Prasanna

Here we are providing A Dog Named Duke Extra Questions and Answers Class 9 English Literature Reader, Extra Questions for Class 9 English was designed by subject expert teachers. https://ncertmcq.com/extra-questions-for-class-9-english/

A Dog Named Duke Extra Questions and Answers Class 9 English Literature

A Dog Named Duke Extra Questions and Answers Short Answer Type

Answer the following questions briefly.

Question 1.
Why was Duke put in a kennel?
Answer:
Duke was put in a kennel because Chuck had an accident which meant he would not be returning home for a long time. Marcy also would not be home much and there would have been no one to take care of Duke.

Question 2.
Why did Chuck not show much improvement in the hospital?
Answer:
Chuck was probably not being able to come to terms with the fact that he would never regain his health but would remain a cripple all his life. This thought depressed him and slowed down his rate of recovery.

Question 3.
How did Duke behave when he saw Chuck after he came back from the hospital?
Answer:
Duke was so excited to see his master that he launched himself on his master causing him to almost fall down.

Question 4.
Did Duke’s return have any effect on Hooper?
Answer:
After the first day when Duke threw himself on him and Chuck had stood up to welcome him, Chuck did not show any more enthusiasm. He would spend his days in silence, staring at the ceiling for hours.

Question 5.
“The dog knew instantly”—What did he know? How did he behave thereafter?
Answer:
He instantly realised that his master was not well and after that he never jumped on Chuck again but stayed by his bedside around the clock, staring at him in silence.

Question 6.
“Duke finally couldn’t take it.” What does the narrator mean by this? What change did Duke bring about?
Answer:
Duke could not take the long hours of silence from Hooper and his apathy and listlessness. He started poking and nudging Chuck till at last Chuck was forced to respond.

Question 7.
“It was like lighting a fuse. Duke shimmied himself U-shaped in anticipation.” Explain.
Answer:
This line refers to the effect Chuck had on the dog when his good hand idly hooked the leash onto the dog’s collar. The dog jumped up in anticipation that his master would take him for a walk. It made the dog all excited.

Question 8.
“The pair set daily goals.” Who were the pair? What were their daily goals?
Answer:
The “pair” refers to Chuck and his dog Duke. Their goal refers to their determination to get Chuck walking and resuming his normal life. Every day they increased the distance and walked till Chuck was able to walk long distances without help from Duke.

Question 9.
What did Duke do when his master fell in his attempt to walk?
Answer:
Duke would stand very still while his master struggled to get up. It seemed as if he felt it was his job to get his master back on his feet.

Question 10.
Did Chuck give up after Duke’s death? Give reasons for your answer.
Encourage the students to think creatively and formulate their own answer.
Answer:
No, Chuck continued to walk and work as he had done with Duke by his side. He had realised the deep love, dedication, and patience that the dog had shown in getting him back on his feet and he could not let all that effort go in vain.

A Dog Named Duke Extra Questions and Answers Long Answer Type

Question 1.
Describe the first attempts made by Hooper to walk.
Answer:
Hooper’s good hand held onto the leash attached to the dog’s collar and he asked Marcy to help him to his feet. With Marcy supporting him by the elbow, he moved his right leg out in the front, causing the left foot to drag forward alongside the right leg. Duke felt the sudden slackness in his leash and he pulled it tight. Chuck swayed forward, broke the fall with his right leg, and then straightened.

Thrice he repeated the same before collapsing into his wheelchair, thus taking his first step since his accident. Everyday thereafter the dog and his master would set targets for the day, slightly further from the day before and not rest till the target for the day was accomplished. In this way from one step they took several steps to reach the door and finally covered the neighbourhood and beyond.

Question 2.
Write a character sketch of Chuck Hooper. What kind of a man do’you think he was?
Answer:
Before the accident Chuck appears to be a happy-go-lucky m$n who has everything going for him. He has a job, a loving wife, a comfortable home with a dog he loves, and the opportunity to play in the football team. But the accident brings out the real depth of his character. After he shakes off his initial despair and gloom, he appears to be a determined, persevering young man who is not afraid to stretch his limits. He shows tremendous courage in facing his handicap and finding a way to live life on his terms in spite of it. He also has the sensitivity to appreciate the dog’s efforts to help him. His hard working nature and independence is apparent in the way he comes back to work and is promoted due to the excellent work that he puts in.

Question 3.
Charles Hooper writes a diary entry after Duke dies, detailing the impact the dog has had on his life. Write the entry.
Answer:
12 April 20xx
Duke died today. A part of me has been buried with him. There is much that I have to thank Duke for. After my accident I saw no reason to live. I lay in my bed for months staring at the ceiling. Marcy, my wife was so upset to see me so morose and depressed. That is when she decided to bring Duke back home from the kennel where she had put him while I was in hospital. The day he returned I tried to stand up to welcome

him. With a giant leap he launched himself on me. He was so excited and happy to see me! But he was so sensitive; he immediately sensed that all was not fine with me. After that he never jumped on me but sat by my bedside quietly staring at me. For some weeks he sat patiently but one day he decided to take me outside and started prodding and nudging me till I had to give in and try to stand.

I can never forget the care and effort he put in to help me walk. I would hold on to his leash while he would walk forward holding it tight waiting for me to drag my legs till I reached him, then he would run ahead and wait for me. In this way I started walking—first a few steps then some more and finally around the neighbourhood. I owe Duke so much. It is really hard to let him go. May you rest in peace!

Question 4.
Marcy writes a letter to her mother in another city informing her about the change in Chuck’s attitude since the return of Duke, mentioning the effort Duke has been putting in goading Chuck out of the bed. Write the letter.
Answer:
15 August 20xx XYZ
Dear Mother,
I never thought there would be a day when I would be grateful to Duke! But it is true, that dog is a wonder! He has managed to get Chuck out of his bed today! I could hardly imagine this was possible.

When I returned from work I saw Chuck standing holding on to Duke’s leash. Then Duke moved ahead and waited with his leash tight while Chuck slowly shuffled his legs to move forward till he was just behind Duke and the leash was loose. Then Duke again moved forward and stood with his leash straining tight. Once again • Chuck moved forward but was so tired out by the effort that he collapsed into his wheelchair!

I am so happy, Duke is such a godsend. He is so sensitive in spite of his huge size. He understands Chuck’s needs and adjusts his movements to suit Chuck’s. He is better than any physiotherapist! He has got my Chuck once again interested in life. Now I am hopeful that Chuck will resume as normal a life as possible under the circumstances.
Your daughter,
Marcy

A Dog Named Duke Extra Questions and Answers Reference to Context

Read the extracts given below and answer the questions that follow.

Question 1.
In 1953, Hooper was a favoured young man. A big genuine grin civilized his highly competitive nature. Standing six-foot-one, he’d played on the university football team. He was already a hard-charging zone sales manager for a chemical company. Everything was going for him.
(a) With reference to Hooper, the author says, “Everything was going for him.” What does it imply?
Answer:
The author implies that Hooper had everything that a man aspires for.

(b) What was Hooper’s occupation and what made him well suited for the job?
Answer:
Hooper was a hard-charging zone sales manager for a chemical company. He was well suited because of his pleasant personality and competitive nature.

(c) In your own words can you define what hard-charging means?
Answer:
Hard-charging means ambitious or working or performing with a lot of energy and skill

Question 2.
“Hooper was taken to the hospital with a subdural haemorrhage. ”
(a) How did Hooper get hurt?
Answer:
Hooper got hurt in a car accident.

(b) What does subdural haemorrhage mean?
Answer:
The medical term subdural haemorrhage means bleeding in the brain.

(c) For how long did Hooper have to stay in the hospital?
Answer:
Hooper stayed in the hospital for many months.

Question 3.
“But Chuck did not make much headway. ”
(a) What was wrong with Chuck?
Answer:
Chuck was paralyzed after an accident.

(b) What does “did not make much headway” mean?
Answer:
It means that Chuck did not show any signs of recovering.

(c) How did Chuck regain his enthusiasm for life?
Answer:
He regained his enthusiasm for life because of his dog, Duke

Question 4.
“Finally they decided to bring Duke home. ”
(a) Whom does “they” refer to?
Answer:
In the given extract “they” refers to Hooper and his wife.

(b) Where had Duke been?
Answer:
Duke had been put in a kennel after Hooper met with an accident.

(c) Why did they decide to bring Duke home?
Answer:
Hooper was bed ridden and needed companionship. They decided to bring Duke home as he could help Hooper get out of his listlessness.

Question 5.
Those who saw it said the dog knew instantly. He never jumped on Chuck again. From that moment, he took up a post beside his master’s bed around the clock.
(a) Why did Duke never jump on Chuck again?
Answer:
Duke realised that Chuck was not well and could not balance himself.

(b) The author says that Duke “knew his job”. What was the job?
Answer:
Duke’s job was to look after Chuck.

(c) Explain the phrase ‘around the clock’.
Answer:
The phrase around the clock means all day and all night.

Question 6.
“ Go run around the house Duke. ’ But Duke wouldn’t. He’d lie down with a reproachful eye. ”
(a) Why was Duke unhappy with Hooper?
Answer:
Duke was unhappy with Hooper as Hooper was not showing any interest in getting well.

(b) What do these lines tell us about Duke?
Answer:
These lines tell us that Duke did not wish to leave his master alone. He was determined to make his master get up.

(c) What does the phrase ‘reproachful eye’ mean?
Answer:
The phrase ‘Reproachful eye’ means that Duke was looking at Hooper disapprovingly.

Question 7.
“Duke felt the sudden slack in the leash and pulled it taut. ”
(a) Why did Duke pull his leash?
Answer:
Duke pulled the leash as he was helping Chuck to walk.

(b) What does the word “taut” mean?
Answer:
Taut means very tight.

(c) What was the result of Duke’s help?
Answer:
The result of Duke’s help was that Hooper regained his confidence and started to walk.

Question 8.
“By mid-April, neighbours saw a daily struggle in front of Marcy’s house. ”
(a) What is the “daily struggle” being referred to?
Answer:
Here the “daily struggle” refers to Hooper getting out of the house to practice his walk.

(b) Who were the ones who struggled?
Answer:
Duke and Hooper were the ones who struggled.

(c) What had happened to Hooper?
Answer:
Hooper had become paralyzed after an accident.

Question 9.
“Gordon this isn’t just a visit. Bring me up to date…”
(a) Who is Gordon?
Answer:
‘ Gordon was Hooper’s manager at work.

(b) Who is the speaker?
Answer:
The speaker of the extracted line is Hooper.

(c) What does he mean when he says “this isn’t just a visit?”
Answer:
When Hooper says “this isn’t just a visit”, he means he had come to work.

Question 10.
“Chuck hit the target and after March 1, there was no time for the physiotherapy programme… ”
(a) What target does Chuck hit?
Answer:
The target Chuck had was to work a full day.

(b) What did this prove about Chuck? What was the result of Hooper’s hitting the target?
Answer:
It proved that he was persevering, determined, and painstaking. He was appointed regional sales manager for hitting the target.

(c) What do you mean by physiotherapy?
Answer:
Physiotherapy is the treatment of injuries or disease by exercise or massage.

Question 11.
“They carried the big dog into the house.”
(a) Why did they have to carry the dog into the house?
Answer:
They had to carry the dog into the house because he had been run over by a car.

(b) Who carried the dog in?
Answer:
Marcy carried the dog inside.

(c) How does the person’s present attitude differ from earlier attitude?
Answer:
Marcy did not like the dog earlier but after everything he did for Hooper she loved him now.

Question 12.
“Marcy was not really a dog lover…It took a long time before Marcy was more than polite to the dog. ”
(a) Who was Marcy?
Answer:
Marcy was Hooper’s wife.

(b) Explain “More than polite to the dog”
Answer:
“More than polite to the dog” means Marcy finally accepted the dog in their house.

(c) Why was Marcy wary of the dog at first?
Answer:
Marcy was wary of the dog at first because it was very big and boisterous.

In this page, we are providing Control and Coordination Class 10 Extra Questions and Answers Science Chapter 7 pdf download. NCERT Extra Questions for Class 10 Science Chapter 7 Control and Coordination with Answers will help to score more marks in your CBSE Board Exams. https://ncertmcq.com/extra-questions-for-class-10-science/

Class 10 Science Chapter 7 Extra Questions and Answers Control and Coordination

Extra Questions for Class 10 Science Chapter 7 Control and Coordination with Answers Solutions

Extra Questions for Class 10 Science Chapter 7 Very Short Answer Type

Question 1.
Define ‘reflex action’.  [CBSE 2009]
Answer:
It is an automatic, spontaneous and an immediate involuntary response to a stimulus controlled usually by the spinal cord. e.g. knee jerk movement.

Question 2.
Name the largest cell in the human body.  [CBSE 2003]
Answer:
Nerve cell (Neuron).

Question 3.
Give an example of plant hormone that promotes growth.  [CBSE 2008]
Answer:
Auxin

Question 4.
What are plant hormones?  [CBSE 2008]
Answer:
The chemical substances produced in plants which help in the growth and development of plant, its tissues and other plants.

Question 5.
Name the part of neuron   [CBSE 2008]
(а) where information is acquired.
(b) through which information travels an electrical impulse.
Answer:
(a) Dendrite
(b) Axon

Question 6.
Name two tissues that provide control and coordination in multicellular animals.  [CBSE 2009]
Answer:
Muscular tissues and nervous tissue.

Question 7.
Name the hormone, the secretion of which is responsible for dramatic changes in appearance in girls and boys when they approach 10-12 years of age.   [CBSE 2008]
Answer:
Testosterone released from testes in males, estrogen released from ovaries in females.

Question 8.
Name the hormone that helps in regulating level of sugar in our blood. Name the glands that secretes it. [CBSE 2010]
Answer:
Insulin hormone secreted by pancreas.

Question 9.
Name a plant hormone that inhibits growth. Write its one more function.  [CBSE 2014]
Answer:
Abscisic acid inhibits growth in plants. It also causes closure of stomata during water stress.

Question 10.
A potted plant is made to lie horizontally on the ground. Which part of the plant will show:
(i) Positive geotropism
(ii) Negative geotropism  [CBSE 2010]
Answer:
(i) Roots will shows positive geotropism.
(ii) Shoots will show negative geotropism.

Question 11.
Name a plant hormone which promotes growth in plants.  [CBSE 2008]
Answer:
Auxin is a plant hormone that promotes growth and cell elongation in plants.

Question 12.
State one function each of pons and cerebellum.
Answer:
Pons: Regulates rate of respiration
Cerebellum: Maintains equilibrium of the body during walking, jumping, etc.

Question 13.
Name a gaseous plant hormone. Give its role.
Answer:
Ethylene is a gaseous hormone. It regulates fruit ripening.

Question 14.
How many spinal and cranial nerves are present in human body?
Answer:
Spinal nerves = 31 pairs
Cranial nerves = 12 pairs

Question 15.
What are meninges?
Answer:
The three membranes which cover the brain to protect it are called meninges.

Extra Questions for Class 10 Science Chapter 7 Short Answer Type I

Question 1.
How do we detect smell of hot spicy food from a distance?
Answer:
We have olfactory receptors in our nose which detect the smell of hot spicy food.
This information is transmitted by nerve impulse to olfactory lobes of forebrain which interpret the information.

Question 2.
Why do tendrils coil around hard objects or support?
Answer:
The tendrils coil around hard objects or support due to a stimulus of touch (thigmotropism) which causes less growth on the side in contact with support than the side which is away from it. This unequal growth of two sides of tendril makes it coil around the support.

Question 3.
Name the hormones reponsible for regulation.
(i) Metabolism of carbohydrates, fats and proteins
(ii) Balance of calcium and phosphate
(iii) Blood pressure
(iv) Water and electrolyte balance.  [CBSE 2007]
Answer:
(i) Thyroxin
(ii) Parathyroid hormone
(iii) Adrenaline
(iv) Vasopressin

Question 4.
What is an association neuron?
Answer:
Association neurons are present in cortex part of spinal cord between the sensory neuron and motor neuron. It helps to interconnect the signals between the sensory neuron and motor neuron by forming synapse with axon of sensory neuron and dendrite of motor neuron.

Question 5.
How are the brain and spinal cord protected from mechanical shock?
Answer:
Brain is present in a bony box called cranium (skull), spinal cord is protected by vertebral column. The cerebrospinal fluid present around the brain and spinal cord protect it from mechanical shock.

Question 6.
Which functions are regulated by the forebrain?
Answer:
The thinking part of the brain is forebrain which controls

• Movement of voluntary muscles.
• Hearing, smell, sight, hunger, thirst, pain, etc. by its association areas.
• It also stores information and controls intelligence.

Question 7.
Explain how a squirrel responds a dangerous situation with help of its hormonal system.
Answer:
When a squirrel perceives a dangerous situation, adrenaline hormone is released in its blood which increases its heart beat and blood supply to tissues. This provides energy to its cells and tissues at a faster rate and enables it to run away from emergency situation.

Question 8.
How are sensory neurons different from motor neurons?
Answer:
Sensory neuorons take information from receptors and transmit the impulses towards central nervous system. Motor neurons carry message from control nervous system to the muscle, gland or an organ to enable it to respond.

Question 9.
How are receptors different from effectors?
Answer:
Receptors are cells, tissues or organs which receive the information in form of stimulus. For example, photoreception, gustatory receptors, etc. Effectors are muscles, glands tissues or cells which respond according to the information received through motor neuron from the central nervous system.

Question 10.
Define peripheral nervous system. What are its components?
Answer:
The nerves that directly arise from the central nervous system and contact different parts of our body to help their involuntary controls. Spinal nerves and cranial nerves are components of peripheral nervous system.

Question 11.
Lable the parts (a), (b), (c) and (d) and show the direction of flow of electrical signals in the given figure.

Answer:
(a) Sensory neuron
(b) Spinal cord (part of CNS)
(c) Motor neuron
(d) Effector (Muscle)

Question 12.
Name the plant hormones responsible for the following:
(a) elongation of cells
(b) growth of stem
(c) promotion of cell division
(d) falling of senescent leaves
Answer:
(a) Auxin
(b) Gibberellin
(c) Cytokinin
(d) Abscissic acid

Question 13.
Label the endocrine glands in figure given below.

Answer:
(a) Pineal Gland
(b) Pituitary Gland
(c) Thyroid
(d) Thymus

Question 14.
Label the parts of a neuron in figure given below.

Answer:
(a) Dendrite
(b) Cell Body
(c) Axon
(d) Nerve ending

Question 15.
Match the terms of Column (A) with those of Column (B)

[NCERT Exemplar]
Answer:
(a) (iii)
(b) (iv)
(c) (i)
(d) (ii)

Extra Questions for Class 10 Science Chapter 7 Short Answer Type II

Question 1.
What are nastic and curvature movements? Give one example of each.  [CBSE 2010]
Answer:
The non-directional responses to stimuli are called nastic movements e.g., drooping of leaves of touch-me-not plant. Curvature movement are the movement of plant parts towards or away from stimulus e.g., bending of shoot towards light.

Question 2.
How does feedback mechanism regulate the hormone action? Explain with the help of an example.
Answer:
The presence or absence of a particular hormone can regulate its further formation with the help of a regulatory mechanism called feedback mechanism.

Example: Hypothalamus regulates thyroxin levels in blood by secreting thyroid stimulating hormone (TSH). If the thyroxine levels increases then hypothalamus stop secreting TSH in order to reduce the production of thyroxine from thyroid gland.

Low levels of thyroxin in blood again switches on the release of TSH from hypothalamus to increase levels of thyroxin in blood.

Question 3.
What are the different types of neurons and their functions in the human body?
Answer:
There are mainly three types of neurons:

1. Sensory neuron: They transmit information from receptors towards the central nervous system.
2. Motor neuron: They transmit information from the central nervous system to effectors like muscles or glands.
3. Relay neuron: It serves as a link between the sensory and the motor neurons in the brain or spinal cord.

Question 4.
What are the limitations to the use of electrical impulse?
Answer:
The limitations to electrical impulse are

1. Only those cells used that are connected by nervous tissue, while other tissues do not receive the information directly.
2. It takes some times to reset the mechanism of generation of new electrical impulse once an electrical impulse had been generated.

Question 5.
Depict the mechanism of Nervous tissue action.
Answer:
The mechanism of nervous tissue action is:

Question 6.
What is a tropic movement? Explain with an example. [NCERT Exemplar]
Answer:
The directional movements caused in plants due to an external stimuli are called tropic movements.
Example: During phototropism, the shoot bends towards light and show positive phototropism while the roots bend away from light to show negative phototropism.

Question 7.
What will happen if intake of iodine in our diet is low?  [NCERT Exemplar]
Answer:
Iodine helps in the synthesis of thyroxin hormone from thyroid gland. Thyroxin hormone is necessary for carbohydrate, proteins and fat metabolism.
Deficiency caused due to low level of iodine in diet might result is a disease called goitre in the person.

Question 8.
Answer the following:
(a) Which hormone is responsible for the changes noticed in females at puberty?
(b) Dwarfism results due to deficiency of which hormone?
(c) Blood sugar level rises due to deficiency of which hormone?
(d) Iodine is necessary for the synthesis of which hormone?  [NCERT Exemplar]
Answer:
(a) Oestrogen
(b) Growth hormone
(c) Insulin
(d) Thyroxin

Question 9.
Answer the following:
(a) Name the endocrine gland associated with brain.
(b) Which gland secretes digestive enzymes as well as hormones?
(c) Name the endocrine gland associated with kidneys.
(d) Which endocrine gland is present in males but not in females?  [NCERT Exemplar]
Answer:
(a) Pituitary
(b) Pancreas
(c) Adrenal gland
(d) Testes

Extra Questions for Class 10 Science Chapter 7 Long Answer Type

Question 1.
Differentiate between tropic and nastic movements in plants.  [CBSE 2006]
Answer:
Tropic Movements:

1. There is directional growth of a plant or part of a plant in response to an external stimulus i.e., direction of stimulus controls direction of growth.
2. The effect is more or less permanent.
3. It is easily observed in stems and roots of plants.
4. It occurs due to unequal growth on the two sides of a stem or root.
5. For example, bending of root towards gravity and bending of shoot towards light.

Nastic Movements:

1. The growth or movement is independent of the direction of stimulus.
2. The effect is temporary and reversible.
3. It occurs in specialised parts and organs of plants like leaves and petals of flowers.
4. It usually involves alterations in cell volumes.
5. For example, folding on leaflets of touch-me-not plant on touching them.

Question 2.
Mention one function for each of these hormones:
(a) Thyroxin
(b) Insulin
(c) Adrenaline
(d) Growth hormone
(e) Testosterone
Answer:
(a) Thyroxin: It regulates carbohydrates, fat and protein metabolism.
(b) Insulin: It regulates blood sugar level.
(c) Adrenaline: It increases heart beat rate and supply of blood to various organs.
(d) Growth hormones: It regulates growth and development of an organism.
(e) Testosterone: It controls the bodily features, secondary sexual characters in males during puberty.

Question 3.
How does chemical coordination take place in animals?
Answer:
Hormones secreted by the endocrine glands are directly poured into the blood stream as they are ductless glands. Blood carries these hormones to specific target tissue or organ where they act and trigger a particular biochemical or physiological activity in response to the stimulus received.

Question 4.
Why is the flow of signals in a synapse from axonal end of one neuron to dendritic end of another neuron but not the reverse?  [NCERT Exemplar]
Answer:
The information received by the dendrites of neurons present at receptors is transferred in form of electrical impulse to the cell body, axon and the nerve endings at the ends of axon. At the axonal ends, chemicals are released between junction of two neurons called synapse. The chemical diffuses towards the dendrite of the next neuron where it generates an electrical impulse again. So, the electrical signals change to chemical signals and again to electrical signals for the next neuron.

Since the chemicals Eire released at the axonal ends and absent at dendrite end, the signal travels from axonal end to dendritic end of another neuron but not the reverse i.e., the flow of electrical impulse is unidirectional only.

Control and Coordination HOTS Questions With Answers

Question 1.
While most of our actions are coordinated by the brain, still some of our actions need to be coordinated by the spinal cord. Why?
Answer:
Brain is the thinking part which coordinates the various activities and processes in human beings. But, some actions which need to be quick, automatic and involuntary, do not involve any thinking processes.
So, such immediate responses are coordinated by the spinal cord and are called reflex actions.

Question 2.
The movements shown by the leaves of ‘touch me not’ plant on touching are different from the movement shown by seedling. Elaborate.
Answer:
The opening and closing of the leaves of the ‘touch me not plant’ is a result of water change in amount of water in the plant cells, which is not dependent on growth. But, the movement of the seedling is a growth-dependent movement because it will not show any movement if it is prevented from growth.

Question 3.
The level of hormones should be well balanced in human beings in order to maintain the normal functioning of the human body. Explain this statement with two examples.
Answer:
The level of hormones should be balanced in human beings because a deficiency or excess secretion of some hormones can have adverse effects on the human body. For example,

• A deficiency in the secretion of insulin from the pancreas increases the blood sugar level and causes diabetes.
• A deficiency in the secretion of growth hormone causes dwarfism whereas it excess secretion causes gigantism.

Question 4.
Chemical coordination plays a vital role in the activities of plants. Elaborate.
Answer:
Coordination in human beings is carried out both by the nervous as well as the hormonal system. But, coordination in plants is dependent on the chemicals called as hormones. The hormone auxin and gibberellins help in the growth of the stem. Cytokinins help in cell division. Abscisic acid inhibits growth. Auxin is also involved in the bending of plants towards light.

Question 5.
The response of the body due to reflex actions is faster than those carried out by secretion of adrenaline in emergency situations. Why?
Answer:
The reflex actions are the result of chemical-electrical impulses which are faster as they move through the nerve cell from one point to another, whereas, hormones are first released in the blood and they have to travel to the target site to bring about the response, which takes more time than reflex actions.

Extra Questions for Class 10 Science Chapter 7 Value Based Questions

Question 1.
Villagers living in a hilly area were facing a problem that a lot of children in the village were developing swollen necks. The priest of the village told that it was due to the acts of the villagers who had annoyed their Goddess and they needed to offer sacrifice for getting rid of this problem. Dr. Kamal visited the village and properly listened to the problem of the villagers and advised them to use iodised salt instead of normal salt in their food. Villagers agreed to Dr. Kamal’s advice and within a few months the problem was overcome to a large extent.
(a) What was the cause of the swollen neck of children in the village?
(b) What values are shown by Dr. Kamal?
(c) Why was use of iodised salt advised to villagers by Dr. Kamal?
Answer:
(a) The swollen neck is a disease called goitre. Goitre occurs due to deficiency of thyroxine hormone.
(b) Scientific aptitude, patience, problem solving ability and helpful nature.
(c) The use of iodised salt was advised because Iodine helps in production of thyroxine hormone which helps to prevent goitre.

Question 2.
Akhilesh saw a plant in his school garden which closed its leaves on touching. He observed the plant very closely for a long time. In the recess, he saw that some students were trying to pluck the plant from the pot. He went to them and advised them not to pluck the plant as it was their school’s property. He also told them about the importance of the plants and the peculiar behavior of the said plant. In this way, he was able to convince the students to not harm the plant.
(a) Why did the leaves of the plant close on touching?
(b) How is this response of plant different from reflex action in animals?
(c) What values are shown by Akhilesh?
Answer:
(a) The leaves of the sensitive plants like Touch-me-not close on touching as they lose the turgor pressure in cells which causes drooping of its leaves/leaflets.

(b)
Movement in Sensitive Plant:

1. The response is produced due to the change in amount of water in the plant cells.
2. No nerve or specialised tissue involved in the conduction of information.

Reflex action:

1. An automatic, immediate, involuntary response of an organism.
2. It is controlled by the spinal cord.

(c) Environment friendly, responsible, leadership, analytical thinking.

Question 3.
Smita’s father was complaining about frequent urination, pain in legs and a frequent weight loss to Smita’s mother and she discussed the things with her daughter when Smita returned from school. Listening to this Smita told her mother that her father should go and visit a doctor immediately. The doctor diagnosed that Smita’s father was having an elevated level of blood glucose. He should take care of his diet and should exercise regularly to maintain his normal glucose level.
On the basis of the text, answer the following questions:
(i) Name the disease he is suffering from and name the hormone whose deficiency causes it.
(ii) Identify the gland that secretes it and mention the function of this hormone.
(iii) Explain how the time and amount of secretion of this hormone is regulated in human system.
(iv) What values were shown by Smita and her father? [CBSE 2012, 2015]
Answer:
(i) Disease-Diabetes, Hormone: Insulin (deficiency of insulin hormone causes diabetes)
(ii) Gland-Pancreas: The blood glucose level is regulated by insulin hormone secreted by the pancreas.
(iii) Cells of pancreas secrete insulin hormone when level of blood glucose level increases in the blood. Insulin regulates the blood glucose level and its secretion gets reduced when blood glucose level falls down.
(iv) Decision making, intelligence, scientific aptitude and caring nature is shown by Smita. Her father had shown an attitude of carelessness towards his health.

Question 4.
Rajesh found an old man lying on the road asking for help to take him to the hospital. He took the old man to the hospital where doctor told him that the old man was suffering from paralysis, and his blood sugar levels were high. The doctor told him that they have given the old man some injections to reduce the blood sugar level and thanked Rajesh for his helpful attitude.
On the basis of above passage, answer the following:
(i) What can be the cause of high blood sugar levels in the old man?
(ii) Which part of old man’s body might have been effected that has caused paralysis?
(iii) What values have been shown by Rajesh?
(iv) Which injection might have been given to old man by doctor to lower the blood sugar levels?
Answer:
(i) Diabetes due to the lower levels of insulin hormone in the body.
(ii) Nervous system associated with brain or spinal cord might have been effected.
(iii) Helpful, care for elderly.
(iv) Injections of insulin might have been given by the doctor to the old man to lower his blood sugar levels.

In this page, we are providing Metals and Non-metals Class 10 Extra Questions and Answers Science Chapter 3 pdf download. NCERT Extra Questions for Class 10 Science Chapter 3 Metals and Non-metals with Answers will help to score more marks in your CBSE Board Exams. https://ncertmcq.com/extra-questions-for-class-10-science/

Class 10 Science Chapter 3 Extra Questions and Answers Metals and Non-metals

Extra Questions for Class 10 Science Chapter 3 Metals and Non-metals with Answers Solutions

Extra Questions for Class 10 Science Chapter 3 Very Short Answer Type

Metals And Non Metals Class 10 Extra Questions Question 1.
Name the property due to which metals have a shining surface in their pure state.
Answer:
Metallic lustre.

Class 10 Science Chapter 3 Extra Questions Question 2.
Name two most malleable metals.
Answer:
Gold and silver.

Metals And Non Metals Class 10 Extra Questions And Answers Question 3.
Name the most ductile metal.
Answer:
Gold.

Question Bank On Metals And Non-Metals Class 10 Question 4.
Name a metal which occurs in the free state.
Answer:
Gold.

Metal And Non Metals Class 10 Extra Questions Question 5.
Give an example of an elementary substance which is a good conductor of electricity but is not a metal.
Answer:
Graphite.

Ch 3 Science Class 10 Extra Questions Question 6.
Name two metals which are both malleable and ductile.
Answer:
Silver and gold.

Extra Questions Of Metals And Nonmetals Class 10 Question 7.
Name the non-metal which is a liquid.
Answer:
Bromine.

Metals And Non Metals Extra Questions Class 10 Question 8.
Expand PVC.
Answer:
Polyvinyl chloride.

Extra Questions On Metals And Nonmetals Class 10 Question 9.
Name a non-metal which is lustrous.
Answer:
Iodine.

Metals And Non Metals Extra Questions Question 10.
Metal A can displace metal B from BO, the oxide of metal B. Metal B can displace C from solution of CSO₄, the sulphate of metal C. Arrange metal A, B and C in the order of increasing reactivity.
Answer:
C < B < A.

Chapter 3 Science Class 10 Extra Questions Question 11.
Name two metals which can be cut with a knife.
Answer:
Lithium, sodium, potassium

Metals And Nonmetals Class 10 Extra Questions Question 12.
An element forms an oxide A₂O₃ which is acidic in nature. Identify A as a metal or non-metal.  [NCERT Exemplar]
Answer:
Oxides of non-metals are acidic in nature while those of metals are basic in nature. Hence, A must be a non-metal.

Metals And Non Metals Class 10 Question Answer Question 13.
Why does calcium float in water?
Answer:
Calcium reacts with water to form calcium hydroxide and hydrogen. Bubbles of hydrogen gas stick to the surface of calcium, hence it floats.

Class 10 Metals And Nonmetals Extra Questions Question 14.
Arrange the following metals in the decreasing order of reactivity Na, K, Cu, Ag.
Answer:
K > Na > Cu > Ag.

Metals And Nonmetals Class 10 Extra Questions And Answers Question 15.
Name the two metals which do not react with water at all.
Answer:
Lead, Copper, Silver and Gold

Question 16.
Name the element which shows non-metallic properties, but is also present in the activity series of metal.
Answer:
Hydrogen.

Question 17.
If X, Y, Z, W, A, B and C represents the metals in the decreasing order of their reactivity, which metal is most likely to occur in free state in nature?
Answer:
C is least reactive, hence .it is likely to occur in the free state.

Question 18.
Name any one metal which reacts neither with cold water nor with hot water, but reacts with heated steam to produce hydrogen gas.
Answer:
Iron
3Fe (s) + 4H₂O (g) → Fe₃O₄ (s) + 4H₂ (g)

Question 19.
Mention the composition of aqua regia.
Answer:
It is a freshly prepared mixture of concentrated hydrochloric acid and concentrated nitric acid in the ratio of 3:1.

Question 20.
In nature, metal A is found in the free state, while metal B is found in the form of its compounds. Which of these two will be nearer to the top of the activity series of metals?
Answer:
Metal B will be nearer to the top because it is more reactive as it is clear from the fact that it exists in the form of its compounds.

Question 21.
Name any two oxides ores.
Answer:

1. Haematite
2. Bauxite.

Question 22.
Which method is used for the concentration of sulphide ores?
Answer:
Froth flotation process.

Question 23.
Complete the chemical equation.

Answer:

Question 24.
What is galvanisation?
Answer:
Galvanisation is a method of protecting steel and iron from rusting by coating them with a thin layer of zinc.

Question 25.
24 Carat gold is not suitable for making jewellery. Why?
Answer:
24 carat gold is very soft, so it is alloyed with either silver or copper to make it hard.

Question 26.
How many carats is pure gold?
Answer:
24 carat.

Question 27.
Name the metal which is used for galvanising iron.
Answer:
Zinc (Zn).

Question 28.
What is meant by 22 carat gold?
Answer:
An alloy consisting of 22 parts by weight of pure gold and 2 parts by weight of copper or silver is called 22 carat gold.

Question 29.
What is an alloy?
Answer:
An alloy is a homogeneous mixture of two or more metals or a metal and a non-metal.

Question 30.
Why do shopkeepers apply oil on tools made of iron while storing them?
Answer:
To protect them from rusting as the oxygen and moisture of the atmosphere will not be able to come in direct contact with the surface of iron.

Question 31.
State two conditions for the rusting of iron.
Answer:

1. Presence of air (or oxygen).
2. Presence of water (or moisture).

Question 32.
Name two metals which are highly resistant to corrosion.
Answer:
Gold and platinum.

Question 33.
Name the gas in air which tarnishes silver particles slowly.
Answer:
Hydrogen sulphide (H₂S).

Extra Questions for Class 10 Science Chapter 3 Short Answer Type I

Question 1.
What happens when
(a) ZnCO₃ is heated in the absence of oxygen?
(b) a mixture of Cu₂O and Cu₂S is heated? [NCERT Exemplar]
Answer:
(a) A mixture of ZnO(s) and CO₂ is formed.

(b) A mixture of copper and SO₂ is formed.

Question 2.
Using the electronic configurations, explain how magnesium atom combines with oxygen atom to form magnesium oxide by transfer of electrons.
Answer:

Question 3.
Name two metals which react violently with cold water. Write any three observations you would make when such a metal is dropped into water. How would you identify the gas evolved, if any, during the reaction?   [CBSE 2008]
Answer:
Sodium, Potassium
When these metals are dropped in water, bubbles will be evolved due to evolution of hydrogen gas.
The gas will catch fire and the solution will be alkaline, i.e., it will turn red litmus blue.

Test: When a burning matchstick is brought near the gas, it burns explosively with a ‘pop’ sound and the splinter is extinguished.

Question 4.
State reasons for the following:
(i) Electric wires are covered with rubber-like material.
(ii) From dilute hydrochloric acid, zinc can liberate hydrogen gas but copper cannot.
Answer:
(i) It is because rubber is an insulator and does not allow current to flow through it.
(ii) Zinc is is placed above hydrogen in the reactivity series of metals while copper is placed below it. Metals placed above hydrogen can displace hydrogen from water and acids while those below it cannot. Therefore, zinc can displace hydrogen from dilute HCl whereas copper cannot.

Question 5.
Give the formulae of the stable binary compounds that would be formed by the combination of the following pairs of elements.
(a) Mg and N₂
(b) Li and O₂
(c) Al and Cl₂
(d) K and O₂
Answer:
(a) Mg₃N₂
(b) Li₂O
(c) AlCl₃
(d) K₂O

Question 6.
Compound X and aluminium are used to join railway tracks.
(a) Identify the compound X
(b) Name the reaction
(c) Write down its reaction.  [NCERT Exemplar]
Answer:
(a) Compound X must be iron (III) oxide, Fe₂O₃.
(b) The reaction is known as ‘thermite reaction’ or ‘aluminothermy’.
(c) The reaction is carried out by igniting the mixture with a Mg-ribbon.

Question 7.
Name two metals which will displace hydrogen from dilute acids, and two metals which will not.
Answer:
Zinc and magnesium can displace hydrogen from dilute acids whereas copper and silver cannot. The metals lying above hydrogen in the reactivity series can displace hydrogen on reaction with dilute acids.

Question 8.
During extraction of metals, electrolytic refining is used to obtain pure metals,
(a) Which material will be used as anode and cathode for refining of silver metal by this process?
(b) Suggest a suitable electrolyte also,
(c) In this electrolytic cell, where do we get pure silver after passing electric current?  [NCERT Exemplar]
Answer:
In the electrolytic refining of impure silver metal:
(a) A rod of impure silver is used as anode while that of pure silver as cathode.
(b) The electrolyte is a water soluble salt of silver, for example silver chloride or silver nitrate.
(c) On passing current, pure silver gets deposited at the cathode. It can be scrapped off later on.

Question 9.
Give reason for the following:
(i) Iron grills are frequently painted.
(ii) Gold ornaments retain their lustre even after several years of use.
Answer:
(i) Iron metal easily gets rusted by air containing moisture and oxygen. Therefore, iron grills are frequently painted with rust proof paints.
(ii) Gold is a noble metal and is not affected by chemicals or by air. Therefore, gold ornaments retain their lustre even after several years.

Question 10.
Name two metals which can be used to reduce metal oxides to metal.
Answer:
(i) Aluminium (Al)

(ii) Magnesium (Mg)

Question 11.
Give the reaction involved during extraction of zinc from its ore by
(a) roasting of zinc ore
(b) calcination of zinc ore   [NCERT Exemplar]
Answer:
(a) Roasting is done for the sulphide ore (zinc blende).

(b) Calcination is done for the carbonate ore (calamine).

Question 12.
The following reaction takes place when aluminium powder is heated with MnO2
3MnO₂(s) + 4Al(s) → 3Mn(l) + 2Al₂O₃(l) + Heat [NCERT Exemplar]
(a) Is aluminium getting reduced?
(b) Is MnO₂ getting oxidised?
Answer:
(a) Aluminium is getting oxidised to Al₂O₃.
(b) Manganese dioxide is getting reduced to Mn.

Question 13.
Differentiate between roasting and calcination process used in metallurgy. Give one example of each.
Answer:

Question 14.
Write chemical equations for the reactions taking place when
(a) Magnesium ribbon is burnt in a jar containing oxygen
(b) Sodium metal falls into a sink containing water
Answer:
(a)

(b) 2Na + 2H₂O → 2NaOH + H₂

Question 15.
What is an amalgam? Write the constituent metals of brass.
Answer:
An amalgam is an alloy in which one of the metals is mercury.
Brass is an alloy of copper and zinc (Cu and Zn). It contains 80% copper and 20% zinc.

Question 16.
Every ore is a mineral but not every mineral is an ore. Explain.
Answer:
Every mineral is not suitable for the extraction of the metal. The mineral from which the metal is economically and conveniently extracted is called an ore.

Extra Questions for Class 10 Science Chapter Short Answer Type II

Question 1.
What is an alloy? How is it prepared? Name the alloy which is used for welding electrical wires together.
Answer:
Alloy is a mixture of two or more metals or non-metals.
Alloys are made by mixing the metals in their molten state. It is prepared by first melting the primary metal and then dissolving the other metal in definite proportion. It is then cooled to room temperature. Solder is used for welding electrical wires together.

Question 2.
Give reasons for the following observations:
(i) Ionic compounds in general have high melting and boiling points.
(ii) Highly reactive metals cannot be obtained from their oxides by heating them with carbon.
(iii) Copper vessels get a green coat when left exposed to air in the rainy season.
Answer:
(i) Ionic compounds have high melting and boiling points due to strong force of attraction between oppositely charged ions.

(ii) It is because these metals, have great affinity towards oxygen and so cannot be reduced by carbon or carbon monoxide or hydrogen.

(iii) Copper vessels react with CO₂, O₂ and moisture to form green coloured basic copper carbonate [CuCO₃. CU(OH)₂] on their surface when exposed to moist air.

Question 3.
E is an element amongst copper, zinc, aluminium and iron. It shows the following properties:
Answer:
(a) One of its ores is rich in E₂O₃.
(b) E₂O₃ is not attacked by water.
(c) It forms two chlorides ECl₂ and ECl₃.
Name the element and justify your answer.
Answer:
The clue for the correct answer is the formation of ECl₂ and ECl₃. This shows that the element E has variable valencies of 2 and 3 out of the elements listed, only iron exists in divalent and trivalent forms.
(a) The ore rich in Fe₂O₃ is haematite.
(b) Haematite (Fe₂O₃) is not attacked by water.
(c) The two chlorides are: Iron (II) chloride or FeCl₂ and iron (III) chloride or FeCl₃.

Question 4.
When a metal X is treated with cold water, it gives a basic salt Y with molecular formula XOH (Molecular mass = 40) and liberates a gas Z which easily catches fire. Identify X, Y and Z and also write the reaction involved. [NCERT Exemplar]
Answer:
The base with molecular mass 40 is NaOH. Hence, the metal X must be sodium (Na). It reacts with H₂O to form the base NaOH and liberates H₂ gas which easily catches fire.

Question 5.
You are provided with three metals: Sodium, magnesium and copper. Using only water as the reactant, how will you identify them?
Answer:

• The metal which reacts violently with cold water and catches fire is sodium.
• The metal which evolves hydrogen gas upon heating with water is magnesium.
• The metal which does not react with water even on strong heating is copper.

Question 6.
A non-metal A is an important constituent of our food and forms two oxides B and C. Oxide B is toxic whereas C causes global warming.
(a) Identify A, B and C.
(b) To which Group of Periodic Table does A belong?  [NCERT Exemplar]
Answer:
The non-metal A is carbon. It is an important constituent of our food in different forms. For example, glucose (C₆H₁₂O₆) contains carbon. In fact, all food materials are organic compounds and these contain carbon as an essential constituent. The two oxides of carbon are, carbon monoxide (B) and carbon dioxide (C). Carbon dioxide causes global warming.

(a) A = Carbon (C); B = Carbon monoxide (CO); C = Carbon dioxide (CO₂)
(b) Carbon is the first member of group 14 in the long form of periodic table.

Question 7.
A non-metal X exists in two different forms Y and Z. Y is the hardest natural substance, whereas Z is a good conductor of electricity. Identify X, Y and Z.   [NCERT Exemplar]
Answer:
Non-metal ‘X’ must be carbon. It exist in two forms, diamond and graphite. Diamond is hardest natural substance. Hence, ‘Y’ is diamond. Graphite is a good conductor of electricity. Hence, ‘Z’ is graphite.

Question 8.
A metal E is stored under kerosene. When a small piece of it is left open in air, it catches fire. When the product formed is dissolved in water, it turns red litmus to blue.
(i) Name the metal E.
(ii) Write the chemical equation for the reaction when it is exposed to air and when the product is dissolved in water.
(iii) Explain the process by which the metal E is obtained from its molten chloride.
Answer:
(i) The available information suggests that the metal (E) is sodium (Na).

The solution is basic and it turns red litmus blue.
(iii) The metal is obtained by the process of electrolytic reduction.

Question 9.
Explain how the following metals are obtained from their compounds by reduction process:
(i) Metal X which is low in reactivity series
(ii) Metal Y which is in the middle of the series
(iii) Metal Z which is high up in the reactivity series.
Give one example of each type.
Answer:
(i) Metals which are low in reactivity series can be obtained by heating their compounds. For example, mercury is obtained by heating its ore, cinnabar (HgS), in air.
HgS + O₂ → Hg + SO₂

(ii) Metals which are in the middle of the series are generally obtained by heating their compounds with some reducing agent such as carbon. For example, iron is obtained from haematite (Fe₂O₃) by reduction with carbon.
2Fe₂O₃ + 3C → 4Fe + 3CO₂

(iii) Metals which are high up in the series are obtained by electrolytic reduction. For example, sodium is obtained by electrolysis of molten sodium chloride.

Question 10.
How is the method of extraction of metals high up in the reactivity series different from that for metal in the middle? Why the same process cannot be applied for them? Explain giving equations, the extraction of sodium.
Answer:
The metals placed high up in the reactivity series (e.g., Na, K, Ca, Mg, Al) are highly reactive and strong reducing agents and are extracted by carrying out the electro-reduction of their molten salts. On the other hand, metals placed in the middle of the series (e.g., Fe, Zn, Cd, Co, Ni, etc.) are comparatively less reactive and are extracted by roasting or calcination.

Sodium is extracted by electro-reduction process.
NaCl ⇌ Na⁺ + Cl^–
Reaction at the cathode: Na⁺ + e⁺ → Na⁺
Reaction at the anode: Cl^– – e^– → Cl
Cl + Cl → Cl₂

Question 11.
Write balanced chemical equation for the reactions taking place when
(i) zinc carbonate is calcinated.
(ii) zinc sulphide is roasted or heated in air.
(iii) zinc oxide is reduced to zinc.
Answer:

Extra Questions for Class 10 Science Chapter 3 Long Answer Type

Question 1.
Explain the following:
(a) Reactivity of Al decreases if it is dipped in HNO₃.
(b) Carbon cannot reduce the oxides of Na or Mg.
(c) NaCl is not a conductor of electricity in solid state whereas it does conduct electricity in aqueous solution as well as in molten state.
(d) Iron articles are galvanised.
(e) Metals like Na, K, Ca and Mg are never found in their free state in nature.   [NCERT Exemplar]
Answer:
(a) On dipping in HNO₃, the surface of Al is oxidised to form an oxide layer of Al₂O₃, which is hard and impervious. It acts as a protective layer for Al underneath. Hence, reactivity of Al decreases.

(b) Na or Mg are highly reactive metals. They have greater affinity for oxygen than for carbon. Hence, their oxides are stable. To reduce them with carbon, very high temperature is required. At this temperature, these metals react with carbon to form corresponding carbides.

(c) The conduction of electricity is due to movement of ions. In the solid state, Na⁺ and Cl^– are fixed and not free to move. Hence, it does not conduct electricity. In the aqueous solution or in the molten state, Na⁺ and Cl^– ions are free to move about and hence conduct electricity.

(d) Galvanisation means coating of iron articles with a layer of zinc. Zinc is more reactive than iron. Hence, it undergoes oxidation more readily than iron. As a result, iron articles remain protected.

(e) These metals are highly reactive and react with the gases present in the air. Hence, they are found as compounds in the ores and not in the free state in nature.

Question 2.
(i) Given below are the steps for extraction of copper from its ore. Write the reaction involved.
(a) Roasting of copper (I) sulphide.
(b) Reduction of copper (I) oxide with copper (I) sulphide.
(c) Electrolytic refining.
(ii) Draw a neat and well labelled diagram for electrolytic refining of copper.   [NCERT Exemplar]
Answer:
(i)

This reaction in which one of the reactants (Cu₂S) carries the reduction of the product (Cu₂O) is known as auto-reduction.

(c) Reaction taking place in electrolytic refining are:
At cathode (reduction): Cu²⁺(aq) + 2e^– → Cu(s)
At anode (oxidation): Cu(s) → Cu²⁺ (aq) + 2e^–

(ii) Metals like copper, aluminium and zinc are refined by this process.

Question 3.
(a) In the formation of compound between two atoms A and B, A loses two electrons and B gains one electron.
(i) What is the nature of the bond between A and B?
(ii) Suggest the formula of the compound formed between A and B.
(b) On similar lines explain the formation of MgCl₂ molecule.
(c) Common salt conducts electricity only in the molten state. Why?
(d) Why is melting point of NaCl high?
Answer:
(a) (i) Ionic bond

(b) Mg → Mg²⁺ + 2e^–
2Cl + 2e^– → 2Cl^–

(c) Na⁺ and Cl^– ions are free to move in molten state but not in solid state.

(d) It is due to strong force of attraction between Na⁺ and Cl^–.

Question 4.
Two ores A and B were taken. On heating ore A gives CO₂ whereas, ore B gives SO₂. What steps will you take to convert them into metals?  [NCERT Exemplar]
Answer:
Since ore A gives CO₂ and ore B gives SO₂. Therefore, ores are MCO₃ and MS.
A can be obtained

B can be obtained

Metals and Non-metals HOTS Questions With Answers

Question 1.
An element A burns with a golden yellow flame in air. It reacts with another element B,
atomic number 17 to give a product C. An aqueous solution of product C on electrolysis gives a compound D and liberates hydrogen. Identify A, B, C and D. Also write down the equations for the reactions involved.  [NCERT Exemplar]
Answer:
A = Sodium which burns with golden flame in air. It reacts with chlorine (Z = 17) to form sodium chloride.
2Na (s) + Cl₂ (g) → 2NaCl (s)

Hence, B = chlorine and C = sodium chloride

Hence, D = Sodium hydroxide.

Question 2.
What is meant by reactivity series of metals? State which of the following chemical reactions will take place giving suitable reason for each.
I. Zn (s) + CuSO₄ (aq) → ZnSO₄ (aq) + Cu (s)
II. Fe (s) + ZnSO₄ (ag) → FeSO₄ (aq) + Zn (s)
III. Zn (s) + FeSO₄ (aq) → ZnSO₄ (aq) + Fe (s)
Answer:
Reactivity series is a list of metals arranged in the order of their decreasing reactivities (activities).
I. Reaction will take place because Zn is above Cu in the activity series and is more reactive than Cu.
II. Reaction will not take place as Fe is below Zn in the activity series and cannot displace Zn from its solution.
III. Reaction will take place because Zn is more reactive than Fe.

Question 3.
A student has been collecting silver coins and copper coins. One day, she observed a black coating on silver coins and a green coating on copper coins. Which chemical phenomenon is responsible for these coatings? Write the chemical name of black and green coatings.
Answer:
The name of the phenomenon is corrosion. The chemical name of black coating is silver sulphide (Ag₂S) formed due to attack of H₂S gas present in the atmosphere on silver and that of green coating is basic copper carbonate formed due to attack of moist air (CO₂, O₂ and H₂O vapours) on copper.

Question 4.
Iqbal treated a lustrous, divalent element M with sodium hydroxide. He observed the formation of bubbles in the reaction mixture. He made the same observations when this element was treated with hydrochloric acid. Suggest how can he identify the produced gas. Write chemical equations for both the reactions.    [NCERT Exemplar]
Answer:
The divalent element M is a metal. It reacts with both sodium hydroxide (alkali) and dilute hydrochloric acid to evolve hydrogen gas.
M(s) + 2NaOH (aq) → Na₂MO₂ (aq) + H₂(g)
M(s) + 2HCl (aq) → MCl₂ (aq) + H₂(g)
The gas burns with a pop sound when a burning matchstick is brought near it.

Question 5.
A non-metal A which is the largest constituent of air, when heated with H₂ in 1: 3 ratio in the presence of catalyst (Fe) gives a gas B. On heating with O₂ it gives an oxide C. If this oxide is passed into water in the presence of air it gives an acid D which acts as a strong oxidising agent.
(a) Identify A, B, C and D.
(b) To which group of periodic table does this non-metal belong?  [NCERT Exemplar]
Answer:
Non-metal which is the largest constituent of air is nitrogen (N₂). Hence, A = N₂.
When heated with H2 in presence of Fe as catalyst, it forms ammonia (NH₃).

Hence, B = NH₃.
When heated with O₂, it forms nitric oxide (NO).

NO further gets oxidised to NO2 by O2 of the air.
2NO(g) + O₂(g) → 2NO₂(g)
Hence, C = NO₂.

On passing this oxide into water in presence of air (O₂), it gives nitric acid (HNO₃) which is a strong oxidising agent.
4NO₂(g) + 2H₂O(l) + O₂(g) → 4HNO₃(aq)
Hence, D = HNO₃.
Nitrogen belongs to Group 15.

Extra Questions for Class 10 Science Chapter 3 Value Based

Question 1.
Anil and his neighbour Sunil had got their garden fenced with iron rods. Next day Anil saw that Sunil was painting the iron fence. Sunil suggested Anil to do the same to increase the longevity of the iron rods by preventing corrosion. Anil argued that it is a waste of time and his iron rods were strong enough. After reading the above passage, answer the following questions.
(i) Whose opinion was correct? Justify.
(ii) Mention two methods (other than painting) to prevent iron from corrosion.
(iii) What is the chemical formula of rust?
(iv) Mention the values exhibited by Sunil.
Answer:
(i) Sunil’s opinion is correct, it helps to protect iron rods from rusting/corrosion.
(ii) (a) Galvanisation
(b) Cathodic protection
(iii) Fe₂O₃. xH₂O
(iv) Friendship/use of knowledge of Chemistry

Question 2.
Mohan approached a goldsmith and asked him to make some gold ornaments. For this he gave advance money also and demanded that 100% pure gold ornaments be made. The goldsmith suggested Mohan that 22-carat gold ornaments would be more appropriate than 24-carat.
(i) What is the difference between 24-carat gold and 22-carat gold?
(ii) Calculate the % of gold in 22-carat gold.
(iii) Why did the goldsmith suggested for use of 22-carat gold?
(iv) Mention the values exhibited by the goldsmith.
Answer:
(i) 24-carat gold is pure gold (100% pure gold) while 22-carat gold is comparatively less pure.
(ii) % of gold in 22 carat = 100 = 91.7%
(iii) Pure of 24-carat gold is very soft, little malleable and ductile. It is quite difficult to work on it. But 22 carat gold (alloy) is comparatively hard, more malleable and ductile.
(iv) Use of knowledge of chemistry, truth, honesty and professionalism.

In this page, we are providing Acids, Bases and Salts Class 10 Extra Questions and Answers Science Chapter 2 pdf download. NCERT Extra Questions for Class 10 Science Chapter 2 Acids, Bases and Salts with Answers will help to score more marks in your CBSE Board Exams. https://ncertmcq.com/extra-questions-for-class-10-science/

Class 10 Science Chapter 2 Extra Questions and Answers Acids, Bases and Salts

Extra Questions for Class 10 Science Chapter 2 Acids, Bases and Salts with Answers Solutions

Extra Questions for Class 10 Science Chapter 2 Very Short Answer Type

Class 10 Science Chapter 2 Extra Questions Question 1.
Write a balanced chemical equation for the reaction between sodium carbonate and hydrochloric acid indicating the physical state of the reactants and products.   [Foreign 2010]
Answer:
Na₂CO₃ (s) + 2HCl (ag) → 2NaCl (aq) + CO₂ (g) + H₂O (l)

Acids Bases And Salts Class 10 Extra Questions Question 2.
During summer season, a milkman usually adds a small amount of baking soda to fresh milk. Give reason.   [CBSE Sample Paper 2009]
Answer:
A milkman adds a very small amount of baking soda so as to prevent spoilage of milk. It leads to change in the pH which does not allow bacteria and enzymes to act and milk does not become sour due to fermentation.

Acid Bases And Salts Class 10 Extra Questions Question 3.
What is the difference between slaked lime and lime water?  [CBSE 2010]
Answer:
A suspension of Ca(OH)₂ in water is called slaked lime. Water containing traces of Ca(OH)₂ is called lime water.

Chapter 2 Science Class 10 Extra Questions Question 4.
Which acid is present in sour milk or curd?
Answer:
Lactic acid.

Acids Bases And Salts Extra Questions Question 5.
Why is potassium iodide added into common salt to use it as table salt?
Answer:
The iodide present in the salt prevents thyroid disorders.

Extra Questions For Class 10 Science Chapter 2 Question 6.
What are the pH values of distilled water and common salt solution?  [CBSE 2010]
Answer:
Both are neutral and have pH close to 7.

Ch 2 Science Class 10 Extra Questions Question 7.
A dry pellet of a common base B, when kept in open absorbs moisture and turns sticky. The compound is also a by-product of chloralkali process. Identify B. What type of reaction occurs when B is treated with an acidic oxide? Write a balanced chemical equation for one such solution.  [NCERT Exemplar]
Answer:
Dry pellets of sodium hydroxide absorb moisture and turn sticky when kept in open which is also a by-product of chloralkali process.

When sodium hydroxide is treated with an acidic oxide it produces salt and water.

Acid Bases And Salts Extra Questions Question 8.
Which bases are called alkalies? Give an example of an alkali. [CBSE 2009, 2010]
Answer:
Soluble bases are called alkalies. For example, sodium hydroxide (NaOH).

Class 10 Chemistry Chapter 2 Extra Questions Question 9.
A knife, which is used to cut a fruit, was immediately dipped into water containing drops of blue litmus solution. If the colour of the solution is changed to red, what inference can be drawn about the nature of the fruit and why? [CBSE 2011]
Answer:
Since the colour of the blue litmus has changed to red, this means that the fruit juice is acidic in nature.

Acid Base And Salt Extra Question Answer Question 10.
How do H⁺ ions exist in water?
Answer:
H⁺ ions in water combine with water (H₂O) molecules and exist as H₃O⁺ ion, called hydronium ion.

Class 10 Science Ch 2 Extra Questions Question 11.
What should be done as remedy if stung by leaves of nettle plant in the wild?
Answer:
The area should be rubbed with the leaf of dock plant.

Extra Questions Of Acids Bases And Salts Class 10 Question 12.
What happens when nitric acid is added to egg shell?  [NCERT Exemplar]
Answer:
Egg shell is made of calcium carbonate. When nitric acid is added to egg shell calcium nitrate, carbon dioxide and water are formed.
CaCO₃ + 2HNO₃ → Ca(NO₃)₂ + CO₂ + H₂O

Acid Base And Salts Class 10 Extra Questions Question 13.
What is the concentration of H⁺ ion in pure water?
Answer:
10^-7

Ncert Class 10 Science Chapter 2 Extra Questions Question 14.
Which one of these has a higher concentration of H⁺ ions? 1 M HCl or 1 M CH₃COOH.   [CBSE 2009]
Answer:
1 M HCl has higher concentration of H⁺ ions.

Class 10 Chapter 2 Science Extra Questions Question 15.
Name an example of olfactory indicators.
Answer:
Vanilla.

Question 16.
Name the chemical substance present in thick white and yellowish clouds present in the atmosphere of Venus.
Answer:
Sulphuric acid.

Question 17.
What is acid rain?
Answer:
Rainwater having pH less than 5.6, is called acid rain.

Question 18.
Name the hardest substance in the body.
Answer:
Tooth enamel (Calcium phosphate).

Question 19.
The pH of three solutions A, B and C are 4, 9 and 6 respectively. Arrange them in increasing order of acidic strength. [CBSE 2010]
Answer:
The increasing order of acidic strength is : B < C < A.

Question 20.
Name the chemist who had given the pH scale.
Answer:
S.P.L. Sorensen (1909).

Question 21.
Name the acid present in tomato.
Answer:
Oxalic acid.

Question 22.
Acidic and basic solutions in water conduct electricity. Why?
Answer:
Because they produce hydrogen and hydroxide ions respectively.

Question 23.
What would be the colour of litmus in a solution of sodium carbonate?   [CBSE 2009]
Answer:
Red litmus will change to blue in sodium carbonate solution.

Question 24.
The pH of a sample of vegetable soup was found to be 6.5. How is this soup likely to taste?
Answer:
The taste will be slightly sour as it is weakly acidic.

Question 25.
Name the chemical substance which is used in the manufacture of soap as well as used as a preservative in pickles.
Answer:
Sodium chloride (NaCl).

Question 26.
There are two jars A and B containing food materials. Food in jar ‘A’ is pickled with acetic acid while ‘B’ is not. Food of which of jar will stale first? Explain. Name two synthetic indicators which are used to test acids and bases.
Answer:
Food in jar ‘B’ will stale first because it will undergo oxidation and will also be attacked by microorganisms.
Synthetic indicators: Phenolphthalein, methyl orange.

Question 27.
What is the chemical formula of soda ash?
Answer:
Na₂CO₃

Question 28.
Name the substance used for disinfecting drinking water supply.
Answer:
Bleaching powder.

Question 29.
Name a chemical substance which can be used to detect the presence of moisture in a liquid.
Answer:
Anhydrous copper sulphate.

Question 30.
What is meant by water of crystallisation?
Answer:
Water of crystallisation is the fixed number of water molecules chemically attached to each formula unit of a salt in its crystalline form.

Question 31.
Which one is a stronger acid, with pH = 5 or with pH = 2?
Answer:
The acid with pH = 2 is a stronger acid.

Question 32.
Fresh milk has a pH of 6. When it changes into curd (yogurt), will its pH value increases or decrease? Why?
Answer:
Its pH will decrease because curd (yogurt) is sour in taste due to presence of acid in it.

Extra Questions for Class 10 Science Chapter 2 Short Answer Type I

Question 1.
How would you distinguish between baking powder and washing soda by heating?   [NCERT Exemplar]
Answer:
Baking soda (NaHCO₃) gives carbon dioxide and water vapour on heating at very low temperature. The gas so formed turns lime water milky, which confirms the presence of carbon dioxide gas.

When washing soda (Na₂CO₃) is heated it does not produce carbon dioxide even at high temperatures, but gives off its water of crystallisation to become anhydrous salt.

Question 2.
A sulphate salt of Group 2 element of the Periodic Table is a white, soft substance, which can be moulded into different shapes by making its dough. When this compound is left in the open for some time, it becomes a solid mass and cannot be used for moulding purposes. Identify the sulphate salt and why does it show such a behaviour? Give the reaction involved.   [NCERT Exemplar]
Answer:
Calcium belongs to group 2. Calcium sulphate is a white soft substance. It is known as Plaster of Paris, which can be moulded into different shapes by making its dough.

When Plaster of Paris is left for some time in the open, it turns into a solid mass because of reaction with moisture present in the atmosphere. The solid mass so formed is known as gypsum and cannot be further used for moulding.

The above said group 2 element is calcium sulpahte.

Question 3.
Name the acid present in ant sting and give its chemical formula. Also give the common method to get relief from the discomfort caused by the ant sting.   [NCERT Exemplar]
Answer:
The acid present in ant sting: Methanoic acid
Chemical Formula of methanoic acid: HCOOH
Method to get relief from the discomfort caused by the ant sting: Rubbing baking soda over the area of ant sting.
Explanation: Rubbing baking soda (a base) over ant sting neutralises the methanoic acid present in the ant sting and gives relief from pain.

Question 4.
List two differences between acids and bases on the basis of chemical properties.
Answer:
(i) Dilute acids like HCl and H₂SO₄ evolve H₂ gas on reacting with metals like Zn, Mg and Ca, etc. and dilute bases do not evolve hydrogen gas.
(ii) Acids react with oxides of metals while bases react with oxides of non-metals.

Question 5.
List four main differences between acids and bases.
Answer:

Properties	Acids	Bases
1. Taste	Sour	Bitter
2. Action on litmus paper	They turn blue litmus paper red	They turn red litmus paper blue.
3. Action with phenolphthalein	No action	They turn phenolphthalein pink.
4. Action with carbonates and bicarbonates	They decompose carbonates and bicarbonates to liberate carbon dioxide.	No action

Question 6.
Mention the terms defined by the following sentences:
(a) A soluble base
(b) The insoluble solid formed when two solution are mixed together.
Answer:
(a) Alkali
(b) Precipitate.

Question 7.
Name the product formed in each case when:
(а) hydrochloric acid reacts with caustic soda.
(b) granulated zinc reacts with caustic soda.
Answer:
(a) The product formed is a mixture of sodium chloride and water.
NaOH (ag) + HCl (ag) → NaCl (ag) + H₂O

(b) The product formed is a mixture of sodium zincate and hydrogen gas.
Zn (s) + 2NaOH (ag) → Na₂ZnO₂ (ag) + H₂(g)

Question 8.
Explain why sodium hydroxide solution cannot be kept in aluminium containers? Write equation for the reaction that may take place for the same.
Answer:
Sodium hydroxide solution reacts with aluminium to form sodium metaaluminate and hydrogen is evolved. Therefore, it cannot be kept in a container made of aluminium.

Question 9.
How can you obtain the following gases by using dilute acid and one other substance?
(а) hydrogen
(b) carbon dioxide.
Answer:
(a) Fe + H₂SO₄(dil.) → FeSO₄ + H₂(g)
Mg + 2HCl(dil.) → MgCl₂ + H₂(g)

(b) Na₂CO₃ + 2HCl(dil.) → 2NaCl + H₂O + CO₂(g)
NaHCO₃ + HCl(dil.) → NaCl + H₂O + CO₂(g)

Question 10.
A solution of HCl is taken in a beaker and an electric circuit with a bulb is set up with the solution in series. What happens to the bulb and why?
Answer:
The bulb will start glowing. Glowing of the bulb indicates that there is a flow of electric current through the solution. Electric current is carried through the solution by ions.

Since the cation present in acids is H⁺, this suggests that acids produce hydrogen ions, H⁺(ag), in solution, which are responsible for carrying current through the solution.

Question 11.
If 280 g of washing soda crystals are left in dry air for some time, a loss of weight of 162 g occurs. How can you account for this?
Answer:
Washing soda (Na₂CO₃. 10H₂O) is an efflorescent substance (if exposed to air, it loses most of its water of crystallisation). 280 g of washing soda lose 162 g of its water of crystallisation.

Question 12.
A sample of bleaching powder was kept in an air tight container. After a month, it lost some of its chlorine content. How will you account for it?
Answer:
Bleaching powder if kept even in an air tight container, will slowly decompose on its own and form calcium chlorate and calcium chloride. The reaction is called auto oxidation. This will result in decrease in its chlorine contents.

Question 13.
A compound which is prepared from gypsum has the property of hardening when mixed with proper quantity of water. Identify the compound. Write chemical equation to prepare the compound. Mention one important use of the compound.
Answer:
The compound is Plaster of Paris (CaSO₄. \(\frac { 1 }{ 2 }\) H₂O). It is formed from gypsum (CaSO₄ . \(\frac { 1 }{ 2 }\) H₂O) upon heating to a temperature of 373 K. It changes back to gypsum on adding water. Plaster of Paris is used for setting fractured bones.

Question 14.
A white powder is added while baking breads and cakes to make them soft and fluffy. Write the name of the powder. Name its main ingredients. Explain the function of each ingredient. Write the chemical reaction taking place when the powder is heated during baking.   [CBSE 2012, 2013]
Answer:
The white powder is known as baking powder. The main ingredients are baking soda (NaHCO₃) and tartaric acid (C₄H₆O₆).

Question 15.
Explain giving reasons:
(i) Tartaric acid is a component of baking powder used in making cakes.
(ii) Gypsum (CaSO₄. 2H₂O) is used in the manufacture of cement.
Answer:
(i) Role of tartaric acid in baking powder (mixture of tartaric acid and sodium hydrogencarbonate) is to neutralise sodium carbonate formed upon heating sodium hydrogencarbonate.

In case it is not done, cake will be better and sodium carbonate will also have injurious side effects.

(ii) The role of gypsum (CaSO₄.2H₂O) in the manufacture of cement is to slow down the process of setting of cement.

Extra Questions for Class 10 Science Chapter 2 Short Answer Type II

Question 1.
What will be the action of the following substances on litmus paper?
Dry HCl gas, moistened NH₃ gas, lemon juice, carbonated soft drink, curd, soap solution.  [NCERT Exemplar]
Answer:
Dry HCl gas: No action
Moistened NH₃ gas: Turns red litmus blue.
Lemon juice: Turns blue litmus red.
Carbonated soft drink: Turns blue litmus red.
Curd: Turns blue litmus red.
Soap solution: Turns red litmus blue.

Explanation:

• Dry HCl gas does not liberate hydrogen ion, hence no action takes place with litmus paper.
• NH₃ gas forms ammonium hydroxide with water which turns red litmus paper blue.
• Lemon juice is citric acid, so it turns blue litmus paper red.
• Carbonate soft drink contains carbon dioxide dissolved in water. Carbon dioxide forms carbonic acid with water; which turns blue litmus paper red.
• Curd contains lactic acid and hence turns blue litmus paper red.
• Soap solution is basic in nature hence it turns red litmus paper blue.

Question 2.
When zinc metal is treated with a dilute solution of a strong acid, a gas is evolved, which is utilised in the hydrogenation of oil. Name the gas evolved. Write the chemical equation of the reaction involved and also write a test to detect the gas formed.   [NCERT Exemplar]
Answer:
Zinc metal gives hydrogen gas when it is treated with dilute sulphuric acid. Hydrogen gas is utilised in hydrogenation of oil.
Therefore, the gas evolved is hydrogen.

Test for hydrogen gas: When a burning candle is brought near hydrogen gas, it bums with a pop sound which confirms the presence of hydrogen gas.

Question 3.
(i) Identify the compound of calcium which is a yellowish powder and is used for disinfecting drinking water. Write its chemical name and formulae.
(ii) Write the balanced chemical equation of chlor-alkali process.   [CBSE 2012, 2014]
Answer:
(i) The yellowish white solid is known as bleaching powder. Chemically, it is calcium oxychloride or calcium hypochlorite. Its chemical formula is CaOCl₂.

(ii) Chemical equation for chlor-alkali process is

Question 4.
Explain with suitable reason
(a) Ferric chloride is stored in air tight bottles.
(b) On exposure to atmosphere, Glaublar’s salt loses weight while quicklime gains weight.
(c) Common salt (containing traces of magnesium chloride) becomes sticky during the monsoons.
Answer:
(a) Because ferric chloride is deliquescent in nature.
(b) Glaubar’s salt is efflorescent and loses water of crystallisation whereas quick lime is hygroscopic in nature and absorbs moisture from the air.
(c) This is because magnesium chloride is deliquescent and absorbs moisture from the atmospheric air and becomes moist.

Question 5.
(a) A solution has a pH of 7. Explain how you would
(i) increases its pH
(ii) decrease its pH
(b) If a solution changes the colour of litmus from red to blue, what can you say about its pH?
(c) What can you say about the pH of a solution that liberates CO₂ from sodium carbonate?
Answer:
(a) (i) By adding some alkali like NaOH
(ii) By adding some acid like HCl

(b) Since the solution changes the colour of litmus from red to blue it is alkaline and hence it has pH > 7.

(c) Since the solution liberates CO₂ from sodium carbonate, it should be acidic and has pH < 7.

Question 6.
A compound which is prepared from gypsum has the property of hardening when mixed with proper quantity of water.
(i) Identify the compound.
(ii) Write the chemical equation for its preparation.
(iii) Mention one important use of this compound.
Answer:
(i) Plaster of Paris

(iii) It is used for plastering fractured bones.

Question 7.
Write any three chemical properties of acids.
Answer:
(i) They react with metals to give out hydrogen gas, for example,

(ii) They react with bases to form salt and water, for example,

(iii) They react with metal carbonates to liberate carbon dioxide gas.

Question 8.
Classify the solutions of the following as acids, bases and salts:
Ammonium hydroxide, barium chloride, sodium chloride, sodium hydroxide, sulphuric acid and nitric acid.
Answer:

Acids	Bases	Salts
1. Sulphuric acid	Ammonium hydroxide	Barium chloride
2. Nitric acid	Sodium hydroxide	Sodium chloride

Question 9.
You are given two solutions A and B. The pH of solution A is 6 and pH of solution B is 8.
(i) Which solution is acidic and which is basic?
(ii) Which solution has more H+ ion concentration?
(iii) Why is HCl a stronger acid than acetic acid?   [CBSE 2011]
Answer:
(i) The solution with pH 6 is acidic while the solution with pH 8 is basic.
(ii) The solution with pH 6 has more H⁺ ion concentration.
(iii) HCl is a stronger acid than CH₃COOH since its degree of dissociation (α) is more or it releases more H+ ions in solution than acetic acid.

Question 10.
What is tooth enamel chemically? State the conditions when it starts corroding. What happens when food particles left in the mouth after eating degrade? Why do doctors suggest use of powder/tooth paste to prevent tooth decay? [CBSE 20011, 2014]
Answer:
(i) The tooth enamel is chemically calcium phosphate with the formula Ca₃(PO₄)₂. It is quite hard.
(ii) The enamel starts corroding when the pH inside our mouth falls below 5.5 because the saliva present in the mouth becomes acidic.
(iii) The bacteria present in the mouth breakdown the food particles into acids which damage our teeth by corroding them.
(iv) The contents of the tooth paste are of basic nature. They neutralise the excess acid present. As a result, the corrosion of enamel and decay of teeth are checked.

Question 11.
(a) Write the name given to bases that are highly soluble in water. Give an example.
(b) How is tooth decay related to pH? How can it be prevented?
(c) Why does bee sting cause pain and irritation? Rubbing of baking soda on the sting area gives relief. How?
Answer:
(a) Alkali, for example, NaOH (Sodium hydroxide).

(b) Lower the pH, more will be tooth decay. Acid formed in the mouth reacts with enamel which is made up of [Ca₃(PO₄)₂] and causes tooth decay.
It can be prevented by brushing our teeth after every meal.

(c) A bee injects formic acid into the skin when it stings which causes pain and irritation. Sodium hydrogencarbonate (baking soda) neutralises formic acid giving relief.

Question 12.
Mention the colour changes observed when the following indicators are added to acids:
(i) Alkaline phenolphthalein solution
(ii) Methyl orange solution
(iii) Neutral litmus solution
Answer:
(i) It gets decolourised
(ii) It turns red or pink
(iii) It turns red.

Question 13.
Choosing only substances from the list given in the box below, write equations for the reactions which you would use in the laboratory to obtain:
(a) Sodium sulphate
(b) Iron (II) sulphate
(c) Zinc carbonate.
Dilute sulphuric acid, copper, iron, copper carbonate, sodium, zinc, sodium carbonate
Answer:
(a) Sodium sulphate
Na₂CO₃ + H₂SO₄ (dil.) → Na₂SO₄ + H₂O + CO₂ (g)

(b) Iron (II) sulphate
Pe + H₂SO₄ (dil.) → FeSO₄ + H₂ (g)

(c) Zinc carbonate
Zn + CuCO₃ → ZnCO₃ + Cu

Question 14.
What is dilution? What precaution should be taken during dilution of a strong acid like sulphuric acid?
Answer:
Dilution is a process in which concentration of a substance decreases by addition of a solvent. Care must be taken while mixing concentrated sulphuric acid with water as the process is a highly exothermic one. The acid must always be added slowly to water with constant stirring. If water is added to a concentrated acid, the heat generated may cause the mixture to splash out and cause burns. The glass container may also break due to excessive local heating.

Question 15.
Write balanced equations to satisfy each statement:
(a) Acid + Chloride → Salt + Hydrochloric acid gas
(b) Acid + Carbonate → Salt + Water + Carbon dioxide
(c) Acid + Sulphite → Salt + Water + Sulphur dioxide
Answer:
(a) H₂SO₄ + NaCl → NaHSO₄ + HCl (g)
(b) 2HCl + Na₂CO₃ → 2NaCl + H₂O + CO₂ (g)
(c) 2HCl + CaSO₃ → CaCl₂ + H₂O + SO₂ (g)

Extra Questions for Class 10 Science Chapter 2 Long Answer Type

Question 1.
What are strong and weak acids? In the following list of acids, separate strong acids from weak acids.  [NCERT Exemplar]
Hydrochloric acid, citric acid, acetic acid, nitric acid, formic acid, sulphuric acid.
Answer:
Strong acid: Strong acids ionise completely in their aqueous solutions to produce a large number of hydrogen ions. Mineral acids are generally strong acids.

Weak acid: Weak acids do not ionise completely in their aqueous solution. Organic acids are generally weak acids.

Strong acid: Hydrochloric acid, nitric acid, sulphuric acid
Weak acid: Citric acid, acetic acid, formic acid

Question 2.
(i) Explain, why is hydrochloric acid a strong acid and acetic acid, a weak acid? How can it be verified?
(ii) Explain, why aqueous solution of an acid conducts electricity?
(iii) You have four solutions A, B, C and D. The pH of solution A is 6, B is 9, C is 12 and D is 7.
(a) Identify the most acidic and most basic solutions.
(b) Arrange the above four solutions in the increasing order of H+ ion concentration.
(c) State the change in colour of pH paper on dipping in solution C and D.   [CBSE 2012, 2013]
Answer:
(i) Hydrochloric acid (HCl) is a stronger acid than acetic acid (CH₃COOH) because it dissociates completely into H⁺ and Cl^– ions in aqueous solution. In order to verify this, add a few drops of universal indicator solution in the test tubes containing the acids. It acquires red colour in hydrochloric acid and yellow in acetic acid which confirms that hydrochloric acid is a stronger acid.

(ii) An aqueous solution of an acid releases ions in aqueous solutions. These ions conduct electricity.

(iii) (a) Most acidic is A (pH = 6) and most basic is C (pH = 12).
(b) The increasing order of H⁺ ion concentration is : C < B < D < A.
(c) The pH paper acquires dark purple colour in solution C and green in solution D.

Question 3.
Fill the missing data in the following table:

Answer:

Question 4.
(a) Explain how antacids give relief from acidity. Write the name of one such antacid.
(b) Fresh milk has a pH of 6. How does the pH change as it turns to curd? Explain your answer.
(c) A milkman adds a very small amount of baking soda to fresh milk. Why does this milk take a longer time to set as curd?
(d) Mention the nature of toothpastes. How do they prevent tooth decay?
Answer:
(a) Our stomach produces hydrochloric acid that helps in digestion of food. During indigestion, our stomach produces excess acid. Antacids neutralise the excess of acid produced and gives relief from hyperacidity. Milk of magnesia (magnesium hydroxide) is one of such antacid.

(b) pH will decrease as it turns to curd because curd is acidic due to the presence of lactic acid.

(c) It takes longer time to set as curd as the presence of baking soda (sodium hydrogen carbonate) makes the milk basic and it does not allow it to become acidic easily.

(d) Toothpastes are basic in nature. They neutralise the acid formed in mouth which causes tooth decay.

Question 5.
(a) Explain the following chemical properties of acids with the help of balanced chemical equations only.
(i) when an acid reacts with a metal carbonate
(ii) when an acid reacts with a metal bicarbonate
(iii) when an acid reacts with a metal oxide.
(b) You are given three solutions A, B and C with pH values 2, 10 and 13 respectively. Write which solution has more hydrogen ion concentration among the three and state the nature ‘acidic or basic’ of each solution.
Answer:
(a) (i) CaCO₃ + 2HCl → CaCl₂ + H₂O + CO₂
(ii) NaHCO₃ + HCl → NaCl + H₂O + CO₂
(iii) Al₂O₃ + 6HCl → 2AlCl₃ + 3H₂O

(b) ‘A’ has maximum [H₃O⁺] equal 10^-2 mol L^-1
‘A’ acidic whereas B and C are basic in nature.

Question 6.
Complete the following reaction:
(i) 2NaCl (aq) + 2H₂O(l) →
(ii) Ca(OH)₂ + Cl₂ →
(iii) NaCl + H₂O + CO₂ + NH₃ →
(iv)
(v) Na₂CO₃ + 10H₂O
Answer:
(i) 2NaCl(aq) + 2H₂O(l) → 2NaOH(aq) + Cl₂(g) + H₂(g)
(ii) Ca(OH)₂ + Cl₂ → CaOCl₂ + H₂O

Acids Bases and Salts HOTS Questions With Answers

Question 1.
A student prepared solutions of (i) an acid and (ii) a base in two separate beakers. She forgot to label the solutions and litmus paper was not available in the laboratory. Since both the solutions were colourless, how would she distinguish between the two?  [NCERT Exemplar]
Answer:
While answering this question, we need to make certain assumptions. Let us assume that laboratory has all the necessary items but no litmus paper. We can use phenolphthalein to check which of the beakers contains acid and which one contains a base. Apart from that, we can also use other natural indicators; like China rose or turmeric.

Question 2.
Salt A commonly used in bakery products on heating gets converted into another salt B which itself is used for removal of hardness of water and a gas C is evolved. The gas C when passed through lime water, turns it milky. Identify A, B and C.  [NCERT Exemplar]
Answer:
Baking powder which is a salt used in bakery products. It give sodium carbonate and carbon dioxide gas on heating. Sodium carbonate is used to remove hardness of water. Carbon dioxide turns lime water milky.

Therefore,

• Salt A, which is sodium bicarbonate and used as baking powder.
• Salt B is sodium carbonate, which is used to remove hardness of water.
• The C is carbon dioxicje gas which turns lime water milky.

Question 3.
In one of the industrial processes used for manufacture of sodium hydroxide, a gas X is formed as by product. The gas X reacts with lime water to give a compound Y which is used as bleaching agent in chemical industry. Identify X and Y giving the chemical equation of the reactions involved.   [NCERT Exemplar]
Answer:
Sodium chloride is used in the manufacture of sodium hydroxide by the Chlor-Alkali process. In this process chlorine and hydrogen gas are formed as by products along with sodium hydroxide. Chlorine gas reacts with lime water to produce bleaching power which is used as bleaching agent in chemical industries.

Therefore,

• The gas ‘X’ is chlorine.
• Compound Y is calcium oxychloride which is commonly known as bleaching powder and used as bleaching agent in chemical industries.

Question 4.
In the following schematic diagram for the preparation of hydrogen gas as shown in Figure. What would happen if following changes are made?   [NCERT Exemplar]
Answer:

(a) In place of zinc granules, same amount of zinc dust is taken in the test tube.
(b) Instead of dilute sulphuric acid, dilute hydrochloric acid is taken.
(c) In place of zinc, copper turnings are taken.
(d) Sodium hydroxide is taken in place of dilute sulphuric acid and the tube is heated.
Answer:
(a) When zinc dust is taken instead of zinc granules to react with sulphuric acid, hydrogen gas is formed. But the rate of reaction increases in the case of zinc dust compared to zinc granules, because of increased surface area of zinc dust which increases the rate of reaction.

Thus, when zinc dust is used in the place of zinc granules, hydrogen gas is produced at a faster rate.

(b) Zinc granules give hydrogen gas; along with zinc chloride; when they react with hydrochloric acid.

Thus, when hydrochloric acid is used in place of sulphuric acid, zinc chloride is formed instead of zinc sulphate; along with hydrogen gas and the reaction takes place at the same rate.

(c) Copper does not react with dilute acids under normal conditions because copper lies at lower position in the reactivity series and does not displace hydrogen from dilute acids.
Thus, if copper turnings are taken in place of zinc granules, no reaction will take place.

(d) If sodium hydroxide is taken in place of dilute sulphuric acid and the tube is heated, sodium zincate is formed along with hydrogen gas. Heating the test tube will increase the rate of formation of hydrogen gas as heating the reaction mixture increases the rate of reaction.

Question 5.
Identify the compound X on the basis of the reactions given below. Also, write the name and chemical formulae of A, B and C.   [NCERT Exemplar]
Answer:

Answer:

Therefore,

• Compound “X’ is sodium hydroxide (NaOH).
• Compound ‘A’ is zinc sulphate (ZnSO₄).
• Compound ‘B’ is sodium chloride (NaCl).
• Compound ‘C’ is sodium acetate (CH₃COONa).

Question 6.
A metal carbonate X on reacting with an acid gives a gas which when passed through a solution Y gives the carbonate back. On the other hand, a gas G that is obtained at the anode during electrolysis of brine is passed on dry Y, it gives a compound Z, used for disinfecting drinking water. Identity X, Y, G and Z.   [NCERT Exemplar]
Answer:
Calcium carbonate gives carbon dioxide gas when it reacts with hydrochloric acid.

Carbon dioxide turns lime water milky when passed through it because of formation of calcium carbonate. When carbon dioxide; so formed; is passed through lime water, it turns milky because of the formation of calcium carbonate.

On electrolysis of brine, chlorine gas is produced at the anode. Therefore G is Cl₂.
Bleaching powder is used in disinfecting drinking water.
Therefore Z can be CaOCl₂.
When chlorine is passed through dry calcium hydroxide [Ca(OH)₂], bleaching powder CaOCl₂ is formed.

Therefore, Y is calcium hydroxide, Ca(OH)₂.
Since Y reacts with a gas to give a carbonate, the gas is CO₂ and the carbonate is CaCO₃.

Therefore, the metal carbonate X is calcium carbonate, CaCO₃.
Therefore,

• Metal carbonate ‘X’ is calcium carbonate.
• Solution ‘Y is lime water (Calcium hydroxide).
• Gas ‘G’ is chlorine gas.
• Dry Y’ is dry calcium hydroxide (dry slaked lime).
• Compound ‘Z’ is bleaching powder (Calcium oxychloride).

Question 7.
A substance X used as an antacid reacts with hydrochloric acid to produce a gas Y which is used in extinguishers.
(а) Name the substances X and Y.
(b) Write a balanced equation of the reaction between X and hydrochloric acid.   [CBSE 2011]
Answer:
(a) Substance X is sodium hydrogencarbonate (X) and the gas evolved Y is carbon dioxide.
(b)

Question 8.
You are provided with the following materials in your laboratory:
Answer:
Hydrochloric acid (HCl), sulphuric acid, (H₂SO₄), nitric acid (HNO₃), acetic acid (CH₃COOH), sodium hydroxide (NaOH), potassium hydroxide (KOH), calcium hydroxide [Ca(OH)₂], magnesium hydroxide [Mg(OH)₃] and ammonium hydroxide (NH₄OH).
If we test each of the above solutions one by one with a drop of the following indicators, what colour change will you observe?
Red litmus, blue litmus, phenophthalein, methyl orange.
Answer:
Acidic substances: HCl, H₂SO₄, HNO₃, CH₃COOH
They will turn blue litmus red and methyl orange red. There will be no effect on red litmus and phenolphthalein.

Basic substances: NaOH, KOH, Ca(OH)₂, Mg(OH)₂, NH₄OH. They will turn red litmus blue and phenolphthalein pink. There will be no effect on blue litmus and methyl orange.

Question 9.
The crystals of a compound A on keeping in air get converted into a white powder. Its solution in water gives blue colour with red litmus. It is used to remove permanent hardness from water.
(a) Identify the substance. Write chemical formula for its crystalline form.
(b) From the given information, identify the nature of the substance.
(c) Write two more uses of the substance.   [CBSE 2013]
Answer:
(a) The substance is washing soda. Its chemical formula is Na₂CO₃.10H₂O.
(b) Since the aqueous solution of the substance in water turns red litmus blue, it is of basic nature.
(c) (i) It is used in laundry for washing clothes.
(ii) It is used in the manufacture of glass, paper and chemicals like caustic soda (NaOH), and borax (Na₂B₄O₇), etc.

Question 10.
A substance X is used as a building material and is insoluble in water. When reacted with dilute HCl, it produces a gas which turns lime water milky. Predict the substance. Write the chemical equations evolved.
Answer:
The substance is probably calcium carbonate (CaCO₃), also called lime stone or marble. It is used as a building material. On reacting with dilute HCl, it evolves CO₂ gas which turns lime water milky.

Question 11.
When electricity is passed through a common salt solution, sodium hydroxide is produced along with the liberation of two gases ‘X’ and T. The gas ‘X’ burns with a pop sound whereas T is used for disinfecting drinking water.  [CBSE 2011]
(i) Identify X and Y.
(ii) Give the chemical equation for the reaction stated above.
(iii) State the reaction of Y with dry slaked lime.
Answer:
(i) The gas X’ is H₂ and gas ‘Y’ is Cl₂.
(ii) The chemical equation for the reaction is:

(iii) Cl₂ reacts with slaked lime to form bleaching powder.
Ca(OH)₂ + Cl₂ → CaOCl₂ + H₂O

Extra Questions for Class 10 Science Chapter 2 Value Based

Question 1.
Aman is fond of eating fast foods and chat. He was suffering from a stomach pain and indigestion for a number of days. Doctor advised him to take antacid tablet after each meal and avoid spicy and junk food. He followed the advice and was cured rapidly.
(i) What is an antacid?
(ii) How are antacid tablets helpful in such indigestion? Justify by the relevant chemical reaction.
(iii) Mention the values exhibited by Aman and the doctor.
Answer:
(i) Antacid is a substance which can neutralise acidity in the stomach.
(ii) The antacid tablets or gels contain base like NaHCO₃ or Mg(OH)₂ which neutralise the effect of excess HCl released in the stomach as
NaHCO₃ + HCl → NaCl + H₂O + CO₂
(iii) Knowledge of Chemistry, caring.

Question 2.
Ayush has cold drinks, chocolates and sweets every day. His teeth were getting damaged. His science teacher asked him to brush his teeth after every meal as well as after eating sweets.
(i) How do the teeth get damaged due to eating chocolates and sweets?
(ii) Brushing of teeth is helpful and prevent tooth decay. Justify.
(iii) Mention the values exhibited by the science teacher.
Answer:
(i) On eating sweets/chocolates the pH of mouth becomes less than 5.5, so tooth enamel gets corroded and tooth decay starts.
(ii) Using toothpaste, which is basic in nature can neutralise the excess acid formed in the mouth and prevent tooth decay.
(iii) Caring, helpful nature, knowledge of Chemistry.

Question 3.
Mohan and Priyanka were playing in the garden. Priyanka was stung by a bee and started crying and returned home. Her mother immediately observed the affected area and applied a thin coating of toothpaste as first aid, then took her to the nearest doctor.
(i) Why did Priyanka cry?
(ii) Name the chemical substance present in bee sting.
(iii) How is toothpaste effective in such incident?
(iv) Mention the values exhibited by Priyanka’s mother.
Answer:
(i) Priyanka cried because the bee injected an acid while stinging which caused pain and irritation.
(ii) Formic acid or Methanoic acid (HCOOH)
(iii) Toothpaste is basic in nature so it neutralise the effect of formic acid and gives relief.
(iv) Knowledge of Chemistry, caring nature.

Question 4.
Manshi is a student of class X in a city school. There was a tall tree at the edge of the garden having a large honeycomb attached to it. Some students were playing cricket in the school playground. Suddenly the cricket ball hit the honeycomb due to which a large number of honey-bees started flying here and there. Manshi was stung on her face by a honey-bee. The sting was so painful that Manshi started crying. One of her classmates Shanti quickly got some baking soda and made a paste of it with water. Then she applied the paste on the stung area of the face. On rubbing baking soda solution, Manshi felt a lot of relief from the pain.
(a) What kind of liquid is injected into the skin when honey-bee strings?
(b) Why did rubbing baking soda solution on the stung area of skin give relief from pain?
(c) What type of chemical reaction takes place when baking soda solution is rubbed on the area stung by honey-bee?
(d) What values are exhibited by Shanti and the classmates?
Answer:
(а) Honey-bee sting injects an acidic liquid into the skin.

(b) Baking soda is a mild base. Being a base, baking soda solution neutralises the acidic liquid injected by honey-bee sting and neutralises its effect. This gives relief from pain.

(c) Neutralisation reaction (between an acid and a base)

(d) The values displayed by Shanti and classmates are

• Awareness
• Knowledge of Chemistry and
• Desire to remove the suffering of others.

Here we are providing Introduction to Trigonometry Class 10 Extra Questions Maths Chapter 8 with Answers Solutions, Extra Questions for Class 10 Maths was designed by subject expert teachers. https://ncertmcq.com/extra-questions-for-class-10-maths/

Extra Questions for Class 10 Maths Introduction to Trigonometry with Answers Solutions

Extra Questions for Class 10 Maths Chapter 8 Introduction to Trigonometry with Solutions Answers

Introduction to Trigonometry Class 10 Extra Questions Short Answer Type 1

Trigonometry Class 10 Extra Questions Question 1.
Find maximum value of \(\frac{1}{\sec \theta}\), 0°≤ θ ≤ 90°.
Solution:
\(\frac{1}{\sec \theta}\), (0° ≤ θ ≤ 90°) (Given)
∵ sec θ is in the denominator
∴ The min. value of sec θ will return max. value for \(\frac{1}{\sec \theta}\).
But the min. value of sec θ is sec 0° = 1.
Hence, the max. value of \(\frac{1}{\sec 0^{\circ}}\) = \(\frac{1}{1}\) = 1

Trigonometry Extra Questions Class 10 Question 2.
Given that sin θ = \(\frac{a}{b}\), find the value of tan θ.
Solution:
sin θ = \(\frac{a}{b}\)

Trigonometry Questions For Class 10 Question 3.
If sin θ = cos θ, then find the value of 2 tan θ + cos² θ.
Solution:
sin θ = cos θ (Given)
It means value of θ = 45°
Now, 2 tan θ + cos² θ = 2 tan 45° + cos² 45°

Introduction To Trigonometry Class 10 Extra Questions With Answers Question 4.
If sin (x – 20)° = cos (3x – 10)°, then find the value of x.
Solution:
sin (x – 20)° = cos (3x – 10)°
⇒ cos [90° – (x – 20)°] = cos (3x – 10)°
By comparing the coefficient
90° – x° + 20° = 3x° – 10° = 110° + 10° = 3x° + x°
120° = 4x°
⇒ \(\frac{120^{\circ}}{4}\) = 30°

Class 10 Trigonometry Extra Questions Question 5.
If sin² A = \(\frac{1}{2}\)tan² 45°, where A is an acute angle, then find the value of A.
Solution:
sin²A = \(\frac{1}{2}\)tan² 45°
⇒ sin²A = \(\frac{1}{2}\) (1)² [∵ tan 45° = 1]
= sin² A = \(\frac{1}{2}\)
⇒ sin A = \(\frac{1}{\sqrt{2}}\)
Hence, ∠A = 45°

Extra Questions Of Trigonometry Class 10 Question 6.
If x = a cos θ, y = b sin θ, then find the value of b²x² + a²y² – a²b².
Solution:
Given x = acos θ, y = b sin θ
b²x² + a²y² – a²b² = b²(acos θ)² + a²(b sin θ)² – a²b²
= a²b² cos²θ + a²b² sin² θ – a²b² = a²b² (sin² θ + cos² θ) – a²b²
= a²b² – a²b² = θ (∵ sin² θ + cos² θ = 1)

Trigonometry Class 10 Questions Question 7.
If tan A = cot B, prove that A + B = 90°.
Solution: We have
tan A = cot B
⇒ tan A = tan (90° – B)
A = 90° – B
[∵ Both A and B are acute angles]
⇒ A + B = 90°

Extra Questions On Trigonometry Class 10 Question 8.
If sec A = 2x and tan A = \(\frac{2}{x}\), find the value of 2\(\left(x^{2}-\frac{1}{x^{2}}\right)\) .
Solution:

Class 10 Maths Chapter 8 Extra Questions Question 9.
In a ∆ABC, if ∠C = 90°, prove that sin² A + sin² B = 1.
Solution:
Since ∠C = 90°
∴ ∠A + ∠B = 180° – ∠C = 90°
Now, sin² A + sin² B = sin² A + sin² (90° – A) = sin² A + cos² A = 1

Trigonometry Extra Questions Question 10.
If sec 4A = cosec (A – 20°) where 4 A is an acute angle, find the value of A.
Solution:
We have
sec 4 A = cosec (A – 20°)
⇒ cosec (90° – 4 A) = cosec (A – 20°)
∴ 90° – 4 A = A – 20°
⇒ 90° + 20° = A + 4 A
⇒ 110° = 5 A
∴ A = \(\frac{110}{5}\) = 22°

Introduction to Trigonometry Class 10 Extra Questions Short Answer Type 2

Introduction To Trigonometry Class 10 Extra Questions Question 1.
If sin A = \(\frac{3}{4}\), calculate cos A and tan A.
Solution:
Let us first draw a right ∆ABC in which ∠C = 90°.
Now, we know that

Important Questions For Class 10 Maths Trigonometry With Solutions Question 2.
Given 15 cot A = 8, find sin A and sec A.
Solution:
Let us first draw a right ∆ABC in which ∠B = 90°.
Now, we have, 15 cot A = 8

Trigonometry Class 10 Extra Questions With Solutions Question 3.
In Fig. 10.5, find tan P – cot R.
Solution:

Using Pythagoras Theorem, we have
PR² = PO² + QR²
⇒ (13)² = (12)² + QR²
⇒ 169 = 144 + QR²
⇒ QR² = 169 – 144 = 25
⇒ QR = 5 cm
Now, tan P = \(\frac{QR}{PQ}\) = \(\frac{5}{12}\) and cot R = \(\frac{QR}{PQ}\) = \(\frac{5}{12}\)
tan P – cot R = \(\frac{5}{12}\) – \(\frac{5}{12}\) = 0

Class 10 Maths Trigonometry Extra Questions Question 4.
If sin θ + cos θ = √3 , then prove that tan θ + cot θ = 1.
Solution:
sin θ + cos θ = √3
⇒ (sin θ + cos θ)² = 3
⇒ sin² θ + cos² θ + 2 sin θ cos θ = 3
⇒ 2 sin cos θ = 2 (∵ sin² θ + cos² θ = 1)
⇒ sin θ. cos θ = 1 = sin² θ + cos² θ

⇒ 1 = tan θ + cot θ = 1
Therefore tan θ + cot θ = 1

Extra Question Of Trigonometry Class 10 Question 5.
Prove that \(\frac { 1-sinθ }{ 1+sinθ } \) = (sec θ – tan θ)²
Solution:

Without using tables, evaluate the following (6 to 10).

Question 6.

Solution:

Trigonometry Important Questions Class 10 Question 7.

Solution:

Extra Questions On Introduction To Trigonometry Class 10 Question 8.

Solution:

Trigonometry Problems For Class 10 Question 9.
Evaluate: sin 25° cos 65° + cos 25° sin 65°.
Solution:
sin 25°. cos 65° + cos 25° . sin 65°
= sin (90° – 65°). cos 65° + cos (90° – 65°). sin 65°
= cos 65° . cos 65° + sin 65°. sin 65°
= cos² 65° + sin² 65° = 1.

Class 10 Introduction To Trigonometry Extra Questions Question 10.
Without using tables, evaluate the following:
3 cos 68°. cosec 22° – \(\frac{1}{2}\) tan 43°. tan 47°. tan 12°. tan 60°. tan 78°
Solution:
We have,
3 cos 68°. cosec 22° – \(\frac{1}{2}\) tan 43°. tan 47°. tan 12°. tan 60°. tan 78°.
= 3 cos (90° – 22°). cosec 22° – \(\frac{1}{2}\) . {tan 43° . tan (90° – 43°)}. {tan 12°. tan (90° – 12°). tan 60°}
= 3 sin 22°. cosec 22° – \(\frac{1}{2}\)(tan 43° . cot 43°). (tan 12°. cot 12°). tan 60°
= 3 × 1 – × 1 × 1 × √3 = 3 – \(\frac{\sqrt{3}}{2}\) = \(\frac{6-\sqrt{3}}{2}\).

Question 11.
If sin 30 = cos (θ – 6°) where 30 and (θ – 6°) are both acute angles, find the value of θ.
Solution:
According to question:
sin 3θ = cos (θ – 6°)
cos (90° – 30) = cos (θ – 6°) [∵ cos (90° – θ ) = sin θ]
90° – 3θ = θ – 6° [comparing the angles)
= 4θ = 90° + 6° = 96°
θ = \(\frac{96}{4}\) = 24°
Hence, θ = 24°

Question 12.
If sec θ = x + \(\frac{1}{4x}\), prove that sec θ + tan θ = 2x or \(\frac{1}{2x}\).
Solution:
Let sec θ + tan θ = λ …..(i)
We know that, sec² θ – tan² θ = 1
(sec θ + tan θ) (sec θ – tan θ) = 1
⇒ λ(sec θ – tan θ) = 1
sec θ – tan θ = \(\frac{1}{\lambda}\) …..(ii)
Adding equations (i) and (ii), we get

Question 13.
Find an acute angle θ, when

Solution:

On comparing we get
⇒ tan θ = √3
⇒ tan θ = tan 60°
= θ = 60°

Question 14.
The altitude AD of a MABC, in which ∠A is an obtuse angle has length 10 cm. If BD = 10 cm and CD = 10√3 cm, determine ∠A.
Solution:

∆ABD is a right triangle right angled at D, such that AD = 10 cm and BD = 10 cm.
Let ∠BAD = θ
∴ tan θ = \(\frac{B D}{A D}\)
⇒ tan θ = \(\frac{10}{10}\) = 1
⇒ tan θ = tan 45°
⇒ θ = ∠BAD = 45° … (i)
∆ACD is a right triangle right angled at D such that AD = 10 cm and DC = 10√3 cm.
Let ∠CAD = Φ
∴ tan Φ = \(\frac{CD}{AD}\)
⇒ tan Φ = \(\frac{10 \sqrt{3}}{10}\) = √3
⇒ tan Φ = tan 60°
⇒ Φ = ∠CAD = 60°
From (i) & (ii), we have
∠BAC = ∠BAD + ∠CAD = 45° + 60° = 105°

Question 15.
If cosec θ = \(\frac{13}{12}\), evaluate \(\frac{2 \sin \theta-3 \cos \theta}{4 \sin \theta-9 \cos \theta}\)
Solution:

Question 16.
Prove that

Solution:

Question 17.
Prove that

Solution:
We have,

Question 18.
Prove that:

Solution:

Question 19.
Prove that:

Solution:

Question 20.
Evaluate the following:

Solution:

Question 21.
If tan (A +B) = √3 and tan (A – B) = \(\frac{1}{\sqrt{3}}\); 0° < A + B ≤ 90°; A > B, find A and B.
Solution:
We have, tan (A + B) = √3
⇒ tan (A + B) = tan 60°
∴ A + B = 60° …(i)
Again, tan (A – B) = \(\frac{1}{\sqrt{3}}\)
∴ A – B = 30° … (ii)
Adding (i) and (ii), we have
2A = 90°
⇒ A = 45°
Putting the value of A in (i), we have
45° + B = 60°
∴ B = 60° – 45o = 15°
Hence, A = 45° and B = 15°

Question 22.
If A, B and C are interior angles of a ∆ABC, then show that sin \(\left(\frac{B+C}{2}\right)\) = cos\(\frac{A}{2}\).
Solution:
Since A, B and C are the interior angles of a ∆ABC,

Question 23.
Prove that: (cosec θ – cot θ)² = \(\frac {1-\cos\theta}{1+\cos\theta}\)
Solution:
LHS = (cosec θ – cot θ)²

Question 24.
Prove that:

Solution:

Question 25.
Prove that: (sin A + cosec A)² + (cos A + sec A)² = 7 + tan² A + cot²A.
Solution:
LHS = (sin A + cosec A)² + (cos A + sec A)²
= sin² A + coses² A + 2sin A . cosec A + cos² A + sec² A + 2 cos A . sec A
= (sin² A + coses² A + 2) + (cos² A + sec² A + 2) [sin A. cosec A = 1]
= (sin² A + cos² A) + (coses² A + sec² A) + 4 [cos A. sec A = 1]
= 1 + 1 + cot²A + 1 + tan² A + 4
= 7 + tan² A + cot² A = RHS [∵ 1 + cot²A = coses² A and 1 + tan² A = sec² A]

Question 26.
Prove that:

Solution:

To obtain cot θ in RHS, we have to convert the numerator of LHS in cosine function and denominator in sine function.
Therefore converting sin² θ = 1 – cos² θ, we get

Question 27.
Prove that:

Solution:

Question 28.
Prove that:

Solution:

Question 29.
Without using trigonometric tables, prove that:

Solution:

Question 30.
Evaluate:

Solution:

Introduction to Trigonometry Class 10 Extra Questions Long Answer Type

Question 1.
In ∆PQR, right-angled at Q, PR + QR = 25 cm and PQ = 5 cm. Determine the values of sin P, cos P and tan P.
Solution:

We have a right-angled ∆PQR in which ∠Q = 90°.
Let QR = x cm
Therefore, PR = (25 – x) cm
By Pythagoras Theorem, we have
PR² = PQ² + QR²
(25 – x)² = 5² + x²
= (25 – x)² – x² = 25
(25 – x – x) (25 – x + x) = 25
(25 – 2x) 25 = 25
25 – 2x = 1
25 – 1 = 2x
= 24 = 2x
∴ x = 12 cm
Hence, QR = 12 cm
PR = (25 – x) cm = 25 – 12 = 13 cm
PQ = 5 cm

Question 2.
In triangle ABC right-angled at B, if tan A = \(\frac{1}{\sqrt{3}}\) find the value of:
(i) sin A cos C + cos A sin C (ii) cos A cos C – sin A sin C.
Solution:

We have a right-angled ∆ABC in which ∠B = 90°.
and, tan A = \(\frac{1}{\sqrt{3}}\)
Now, tan A = \(\frac{1}{\sqrt{3}}\) = \(\frac{BC}{AB}\)
Let BC = k and AB = √3k
∴ By Pythagoras Theorem, we have
⇒ AC² = AB² + BC²
⇒ AC² = (√3k)² + (k)² = 3k² + k²
⇒ AC² = 4k²

Question 3.
If cot θ = \(\frac{7}{8}\), evaluate:
(i)

(ii) cot² θ
Solution:
Let us draw a right triangle ABC in which ∠B = 90° and ∠C = θ.

Question 4.
If 3 cot A = 4, check whether \(\frac{1-\tan ^{2} A}{1+\tan ^{2} A}\) = cos² A – sin² A or not.
Solution:

Let us consider a right triangle ABC in which ∠B = 90°

Let AB = 4k and BC = 3k
∴ By Pythagoras Theorem
AC² = AB² + BC²
AC = (4k)² + (3k)² = 16k² + 9k²
AC² = 25k²
∴ AC = 5k

Question 5.
Write all the other trigonometric ratios of ∠A in terms of sec A.
Solution:

Let us consider a right-angled ∆ABC in which ∠B = 90°.
For ∠A we have

Question 6.
Prove that

Solution:

Question 7.
Prove that:

Solution:

Question 8.
Prove that

Solution:

= 2 cosec² A tan² A = 2(1 + cot² A). tan² A
= 2 tan² A + 2 tan² A. cot² A (∵ tan A cot A = 1)
= 2 + 2 tan² A = 2(1 + tan² A) = 2 sec² A = RHS.

Question 9.
Prove that: (sin θ + sec θ)² + (cos θ + cosec θ)² = (1 + sec θ cosec θ)².
Solution:
LHS = (sin θ + sec θ)2 + (cos θ + cosec θ)²

= (1 + sec θ cosec θ)² = RHS.

Question 10.
Prove that:

Solution:
In order to show that,

Question 11.
Prove that: \(\frac { cosecθ\quad +\quad cotθ }{ cosecθ\quad -\quad cotθ } \) = (cosec θ + cot θ) = 1 + 2 cot² θ + 2 cosec θ cot θ.
Solution:

= cosec² θ + cot² θ + 2 cosec θ. cot θ
= (1 + cot² θ) + cot² θ + 2 cosec θ. cot θ
= 1 + 2 cot² θ + 2 cosec . cot θ = RHS.

Question 12.
Prove that: 2 sec θ – sec θ – 2 cosec θ + cosec θ = cot – tan θ.
Solution:
LHS = 2 sec θ – sec θ – 2 cosec² θ + cosec θ
= 2 (sec² θ) – (sec² θ)2 – 2 (cosec² θ) + (cosec θ)²
= 2 (1 + tan² θ) – (1 + tan⁴ θ)2 – 2(1 + cot² θ) + (1 + cot² θ)⁴
= 2 + 2 tan² θ – (1 + 2 tan² θ + tan² θ) – 2 – 2 cot² θ + (1 + 2 cot² θ + cot θ) =
= 2 + 2 tan² θ – 1 – 2 tan² θ – tan⁴ θ – 2 – 2 cot² θ + 1 + 2 cot⁴ θ + cot⁴ θ
= cot⁴ θ – tan⁴ θ = RHS

Question 13.
Prove that: (cosec A – sin A) (sec A – cos A) = \(\frac{1}{\tan A+\cot A}\).
Solution:
LHS = (cosec A – sin A) (sec A – cos A)

Introduction to Trigonometry Class 10 Extra Questions HOTS

Question 1.
Prove that:
\(\frac{\tan \theta}{1-\cot \theta}\) + \(\frac{\cot \theta}{1-\tan \theta}\) = 1 + sec θ cosec θ = 1 + tan θ + cot θ.
Solution:

For second part
Now from (i), we have

Question 2.
If tan A = n tan B and sin A = m sin B, prove that cos² A = \(\frac{m^{2}-1}{n^{2}-1}\)
Solution:
We have to find cos² A in terms of m and n. This means that the angle B is to be eliminated from
the given relations.
Now, tan A = n tan B
⇒ tan B = \(\frac{1}{n}\) tan A
⇒ cot B = \(\frac{n}{\tan A}\)
and
sin A = m sin B

Question 3.
Prove the following identity, where the angle involved is acute angle for which the expressions are defined.
\(\frac { cosA-sinA+1 }{ cos A + sin A-1 } \) = cosec A + cot A, using the identity cosec² A = 1 + cot² A.
Solution:

= cosec A + cot A = RHS.

Question 4.
If x sin³ + y cos³ θ = sin θ cos θ and x sin θ = y cos θ, prove x² + y² = 1.
Solution:
We have, x sin³ + y cos³ θ = sin θ cos θ
⇒(x sin θ) sin² θ + (y cos θ) cos² θ sin θ cos θ
⇒ x sin θ (sin² θ) + (x sin θ) cos² = sin θ cos [∵ x sin θ = y cos θ]
⇒ x sin θ (sin² θ + cos² θ) = sin θ cos θ
⇒ x sin θ = sin θ cos
⇒ x = cos θ
Now, we have x sin θ = y cos θ
⇒ cos o sin θ = y cos θ [∵ x = cos θ]
⇒ y = sin θ
Hence, x² + y² = cos² θ + sin² θ = 1.

Question 5.
If tan θ + sin θ = m and tan θ – sin θ = n, show that (m² – n²) = 4√mn.
Solution:
We have, given tan θ + sin θ = m, and tan θ – sin θ = n, then
LHS = (m² – n²),= (tan θ + sin θ)² – (tan θ – sin )²
= tan² θ + sin² θ + 2 tan θ sin θ – tan² θ – sin² θ + 2 tan θ sin θ

Question 6.
If cosec θ – sin θ = l and sec θ – cos θ = m, prove that l² m² (l² + m² + 3) = 1.
Solution:
LHS = l² m² (l² + m² + 3).
= (cosec θ – sin θ)² (sec θ – cos θ)² {(cosec θ – sin θ)² + (sec θ – cos θ)² + 3}

In this page, we are providing Management of Natural Resources Class 10 Extra Questions and Answers Science Chapter 16 pdf download. NCERT Extra Questions for Class 10 Science Chapter 16 Management of Natural Resources with Answers will help to score more marks in your CBSE Board Exams. https://ncertmcq.com/extra-questions-for-class-10-science/

Class 10 Science Chapter 16 Extra Questions and Answers Management of Natural Resources

Extra Questions for Class 10 Science Chapter 16 Management of Natural Resources with Answers Solutions

Extra Questions for Class 10 Science Chapter 16 Very Short Answer Type

Sustainable Management Of Natural Resources Class 10 Important Questions Question 1.
List any two causes for deforestation taking place.  (CBSE 2009)
Answer:

1. Meeting the needs of growing population and using land for housing.
2. Setting up industries.
3. Converting into agricultural land.

Chapter 16 Science Class 10 Extra Questions Question 2.
Name any two forest products each of which is the basis for some industry. (CBSE 2009)
Answer:

1. Timber wood: Used in making paper and furniture.
2. Latex of rubber plant: In making tyres.
3. Resins and gums: Used in paints and varnishes.

Management Of Natural Resources Class 10 Questions And Answers Pdf Question 3.
Mention any one negative effect of our affluent life style on the environment.  (CBSE 2013, 2014)
Answer:
Chlorofluorocarbons used in refrigerators causing ozone hole. Carbon dioxide released on burning fossil fuels causing global warming.

Management Of Natural Resources Class 10 Important Questions Question 4.
List any two measures that you suggest for better management of water resources.  (CBSE 2013, 2014)
Answer:

1. Rainwater harvesting.
2. Reusing the rinsed water from washed clothes for cleaning or mopping the house.

Management Of Natural Resources Class 10 Questions And Answers Question 5.
Give one example each from your daily life where the household waste can be effectively reused and recycled respectively.  (CBSE 2013, 2014)
Answer:
Reuse: Empty plastic or glass bottles of jams and pickles
Recycle: Paper and empty polypacks of milk.

Class 10 Science Chapter 16 Important Questions Question 6.
Name any two items which can be easily recycled but are generally thrown in the dustbins by us.  (CBSE 2013, 2014)
Answer:
Paper, polypacks of milk, cold drink cans, etc.

Management Of Natural Resources Important Questions Question 7.
Write the main objective of conservation of biodiversity.  (CBSE 2013)
Answer:
To maintain ecological balance as loss of biodiversity leads to ecological instability.

Sustainable Management Of Natural Resources Important Questions Question 8.
Water is a valuable resource. List two ways that you would suggest every family member to save this resource. (CBSE 2014)
Answer:

1. Prevent leakage from tap and ensure timely repairs.
2. Reuse the rinsed water from washed clothes for watering plants in garden.

Management Of Natural Resources Class 10 Extra Questions Pdf Question 9.
“We need to manage our resources”. List two reasons to justify this statement.  (CBSE 2014)
Answer:

1. For equitable distribution of resources so that all people get their benefits.
2. Many resources are limited and would exhaust due to overexploitation.

Extra Questions for Class 10 Science Chapter 16 Short Answer Type I

Class 10 Science Chapter 16 Extra Questions Question 1.
List any four measures for conserving forests.  (CBSE 2009)
Answer:

1. Reduce the indiscriminate felling of trees.
2. Create awareness among people for conservation of forests.
3. Involving local people in management and conservation of forests.
4. Reforestation by promoting silviculture.
5. Providing protection to wildlife and endangered plants.
6. Making strict laws for conservation of forests.

Questions On Sustainable Management Of Natural Resources Question 2.
List any four advantages of water harvesting.  (CBSE 2009)
Answer:

1. Helps to recharge ground water.
2. Underground water does not act as breeding ground of mosquitoes.
3. Underground water does not get contaminated by human and animal wastes.
4. Provides moisture to the soil and crops.

Important Question Of Natural Resources Class 10 Question 3.
We often observe domestic waste decomposing in the by lanes of residential colonies. Suggest ways to make people realise that the improper disposal of waste is harmful to the environment.  (CBSE 2013)
Answer:

• Create awareness through campaigns and road rallies on the issue.
• Impose penalty on those found throwing wastes on the road.

Sustainable Management Of Natural Resources Class 10 Extra Questions Question 4.
List two environment-friendly practices or habits which need to be followed by every member of a family / community. Explain how these practices will support the “save the environment” mission. (CBSE 2014)
Answer:

• Segregation of wastes into biodegradable and non-biodegradable and ensuring their reuse and recycling, if possible.
• Less use of fossil fuels and switching to environment friendly alternatives like use of solar energy and wind energy, etc.

Important Questions From Sustainable Management Of Natural Resources Question 5.
What is meant by “Sustainable Management”? Why is reuse considered better than recycling?  (CBSE 2015)
Answer:
The judicious and wise use of resources to cater to the current basic needs and preserving the resources for the needs of future generations is called as Sustainable Management.
Recycling requires more amount of energy and money while no energy is required for the reuse of materials. So, reuse is better than recycling.

Natural Resources Class 10 Important Questions Question 6.
List two advantages associated with water harvesting at the community level. (CBSE 2015)
Answer:
Water harvesting at community level is advantageous as:

• It recharges the ground water and helps in increasing the vegetation around the area.
• It mitigates the chances of droughts and floods. It also increases income of farmers by increasing agricultural production in rural areas.

Management Of Natural Resources Class 10 Question 7.
Everyone of us can do something to reduce our personal consumption of various natural resources. List four such activities based on 3R’s approach.  (CBSE 2013, 2015)
Answer:

• Reduce wastage of water by repairing leaking taps.
• Recycle the wastes like paper, empty polypacks of milk, etc.
• Reuse the aluminium cans of cold drink, glass bottles of pickles, etc.
• Reduce the use of fossil fuels by switching over to cleaner and renewable sources of energy like solar energy.

Management Of Natural Resources Questions And Answers Question 8.
List two main causes of the pollution of water of the river Ganga. State how pollution and
contamination of river water prove harmful for the health of the people of neighbouring areas. (CBSE 2015)
Answer:
The two main causes of pollution of water of river Ganga are:

1. Disposal of domestic and industrial effluents into it.
2. Human activities like washing clothes, bathing, etc.

The harm to the people of neighbouring areas are:

1. Leads to water-borne diseases like cholera, typhoid, etc.
2. Harms the aquatic plants and animals in the water body.

Management Of Natural Resources Question Answers Question 9.
List any two advantages associated with water stored in the ground.  (CBSE 2015)
Answer:
The water stored in ground

1. does not evaporate
2. does not act as breeding ground of mosquitoes.

Class 10th Science Chapter 16 Question Answer Question 10.
What steps have been taken by West Bangal Government to protect badly degraded sal forests?
Answer:
By the efforts of A.K . Banerjee in Arabari forest range of Midnapore district the badly degraded sal forests were revived with the involvement and participation of local villagers. The villagers were in return given employment and were allowed to collect firewood and fuelwood at a nominal fee.

Management Of Natural Resources Class 10 Solutions Question 11.
Why are forests considered ‘biodiversity hot spots’? What would happen due to loss of biodiversity?
Answer:
Wide variety of plants, animals, microorganisms are found in forests. So they act as biodiversity hotspots. Loss of biodiversity disturbs ecological balance.

Sustainable Management Of Natural Resources Class 10 Solutions Question 12.
Prepare a list of five items that you use daily in the school. Identify from the list such items that can be recycled. (NCERT Exemplar)
Answer:
Paper, Plastic pencil box or Tiffin box, Steel spoon, Scale, Eraser.

Management And Natural Resources Class 10 Question 13.
List two advantages associated with water harvesting at the community level.  (NCERT Exemplar)
Answer:

1. Recharging of wells leads to increase in ground water level.
2. Ground water does not evaporates and keeps the layers of soil above it moist.
3. The water stored during rainy season can be used when required.

Sustainable Management Of Natural Resources Question Answer Question 14.
What measures would you take to conserve electricity in your house?  (NCERT Exemplar)
Answer:

• Switch off the fans and lights when they are not required.
• Use solar water heaters during winters.
• Use LED lights instead of normal bulbs or tube lights.

Question 15.
Although coal and petroleum are produced by degradation of biomass, yet we need to conserve them. Why? (NCERT Exemplar)
Answer:
It takes millions of years to form coal and petroleum and their reserves are limited. Due to this they would get exhausted very soon if utilised at a faster rate. Hence, they should be conserved for the needs of the future generations too.

Question 16.
Suggest a few measures for controlling carbon dioxide levels in the atmosphere.  (NCERT Exemplar)
Answer:

• Plant more and more trees.
• Using cleaner fuels like CNG.
• Make manure from litter instead of burning it.
• The harmful effluents from industries should be treated before discharging them into the atmosphere.
• Less use of fossil fuels.

Extra Questions for Class 10 Science Chapter 16 Short Answer Type II

Question 1.
What are natural resources? State two factors that work against an equitable distribution of these resources. (CBSE 2009)
Answer:
The stock of nature such as air, water, soil, minerals, forests and wildlife are called as natural resources. The two factors that work against their equitable distribution are

1. Overuse of resources and their overexploitation.
2. Human activities like cutting of trees, hunting, etc. which disturbs ecological balance.

Question 2.
What is water harvesting? Mention any two water harvesting structures.  (CBSE 2009)
Answer:
Capturing rainwater where it falls or capturing the run-off water so that it can be made available throughout the year for various purposes is called water harvesting.
Some traditional water harvesting structures are:

1. Khadins, tanks and nadis in Rajasthan
2. Kulhs in Himachal Pradesh.

Question 3.
How can we as an individual help in reducing the use of fossil fuels? Mention two ways.
Answer:
We can reduce the use of fossil fuels by .

1. Switching over to renewable sources of energy like solar energy, wind energy, etc.
2. Use public transport instead of private vehicles,
3. Ensure proper servicing and tuning of vehicles to increase fuel efficiency.

Question 4.
What is meant by exploitation of resources with short aims? List its four advantages.  (CBSE 2009)
Answer:
Use of resources for the benefit of a few rich and powerful people in order to fulfil short-term aims and the present needs is called exploitatation of resources with short aims. Its advantages are:

1. Maximises profit without any accountability.
2. Increases growth rate of economy for that duration.
3. They fulfil the needs of the present generation.
4. Ensures availability of a variety of raw materials for human use.

Question 5.
(a) List any two disadvantages of using fossil fuels for the production of energy.
(b) Give two examples each of the following:
(i) Renewable sources of energy. 3
(ii) Non-renewable sources of energy.  (CBSE 2011)
Answer:
(a) Disadvantages of using fossil fuels:

• The oxides of nitrogen and sulphur released on burning fossil fuels reacts with water vapour in air and falls in the form of harmful acid rain.
• Carbon dioxide released on burning them causes greenhouse effect which leads to global warming.
• Carbon monoxide releases on their combustion is toxic and can be fatal.
• They are limited, non-renewable resources which may get exhausted soon.

(b) (i) Examples of renewable sources of energy are

• Solar energy
• Wind energy

(ii) Examples of non-renewable sources of energy are

• Petrol
• Diesel

Question 6.
Dams are useful for the society but there is public opposition to the construction of large dams. Justify your answer by giving three problems.  (CBSE 2011)
Answer:

• Social problems: Large number of human settlements gets submerged in water during construction of dam.
• Environmental problems: Loss of vast variety of flora-fauna due to deforestation and biodiversity loss during construction of dams.
• Economic problems: Huge amount of public money is spent without getting proportionate benefits from such dams.

Question 7.
List the products of combustion of fossil fuels. What are their adverse effects on the environment?  (CBSE 2012)
Answer:
Carbon dioxide, sulphur dioxide, nitrogen oxide, water, carbon monoxide are the products of combustion of fossil fuels.
Their adverse effects on the environment are:

• Carbon dioxide is a greenhouse gas which leads to global warming.
• Oxides of nitrogen and sulphur react with water vapour present in air to form acids which fall in the form of acid rains and harms life.
• Carbon monoxide is a toxic gas which creates respiratory problems.

Question 8.
What is environmental planning? List any four human activities that are directly connected to influence the environment of a region.
Answer:
Various steps taken to reduce pollution and conserve natural resources for long term use is called environmental planning. It is necessary to maintain ecological balance. Human activities that are directly connected to influence the environment of a region are:

• Large scale deforestation for agricultural land or housing needs of growing population.
• Discharge of domestic wastes and industrial effluents into water bodies.
• Excessive use of fossil fuels which causes air pollution.
• Excessive use of non-biodegradable materials, plastics, detergents, etc. which harm the environment.

Question 9.
What is the full form of GAP? Why was it started? What is the main cause of abundant coliform in the river Ganga?
Answer:
GAP-Ganga Action Plan:
GAP was started to ensure the cleaning of water of river Ganga and reduce the pollution levels of Ganga. Main cause of abundant coliform bacteria in river Ganga is due to high amount of organic wastes disposed in the form of unburnt corpses into the water.

Question 10.
In a village in Karnataka, people started cultivating crops all around a lake which was always filled with water. They added fertilisers to their field in order to enhance the yield. Soon they discovered that the waterbody was completely covered with green floating plants and fishes started dying in large numbers.
Analyse the situation and give reasons for excessive growth of plants and death of fish in the lake. (NCERT Exemplar)
Answer:
The fertilisers containing high amount of phosphates and nitrates got carried down by rainwater into the lake which led to nutrient enrichment of water in lakes. This caused excessive growth of aquatic plants which ultimately covered the whole surface of the water body. Due to this insufficient amount of light entered the water body and levels of oxygen became low. This led to death of fishes in the water body.

Question 11.
(a) Locate and name the water reservoirs in Figures (a) and (b).
(b) Which has an advantage over the other and why?


Answer:
(a) The water reservoir in Figure (a) is a pond.
The water reservoir in Figure (b) is an underground water body.

(b) Figure (b) has more advantage than Figure (a), because the advantages of water stored in the ground are many. For example

• It does not evaporate.
• Spreads out to recharge wells and provides moisture for vegetation over a wide area.
• Does not provide breeding grounds for mosquitoes like stagnant water.

Extra Questions for Class 10 Science Chapter 16 Long Answer Type

Question 1.
What is a dam? Write two main advantages and two ill-effects of constructing big dam.  (CBSE 2009)
Answer:
Dams are constructed across the rivers to regulate the flow of water and store the huge amounts of water in large reservoirs. This ensures the supply of water for irrigation and other purposes.

Advantages of Dams:

• Ensures water availability for irrigation of fields.
• Water can be used to generate electricity in Hydel power stations by using turbines.

Disadvantages of dams:

• Social problems: Human settlements get submerged under water.
• Environmental problems: Large scale loss of biodiversity and deforestation.
• Economic problems: Huge amount of public money utilised in their construction but benefits are not proportionate.

Question 2.
Define Reduce, Recycle and Reuse with reference to the environment. Which is better strategy among recycle and reuse? Why?
Answer:
Recycle: Recycling wastes like paper, plastic and glass to obtain materials for use.
Reduce: Minimise the use of natural resources.
Reuse: Encourage the use of things again and again instead of throwing them away.
Reuse is better than recycling.

Recycling requires large amount of energy and money whereas reuse does not require any energy. So, reuse is better than recycling.

Question 3.
Prepare a list of five activities that you perform daily in which natural resources can be conserved or energy utilisation can be minimised.  (NCERT Exemplar)
Answer:

• Taking a bus, public transport or walking/cycling instead of a private vehicle.
• Using LED bulbs in homes instead of normal bulbs.
• Talking the stairs instead of lift.
• Using fan and light only when required.
• Using solar water heating devices.

Question 4.
Is water conservation necessary? Give reasons.  (NCERT Exemplar)
Answer:
The total amount of fresh water is more than enough to meet the needs of human beings. But due to its uneven distribution, wide seasonal, as well as yearly fluctuation in rainfalls and wastage, water shortage is a chronic problem inmost parts of the world.

Management of Natural Resources HOTS Questions With Answers

Question 1.
What is meant by ‘Sustainable Management’? The environmentalists are insisting upon sustainable natural resources management. State its four advantages.  (CBSE 2009)
Answer:
The judicious and wise use of resources to cater to the current basic needs and preserving the resources for the needs of the future generations is called sustainable management. Its advantages are:

1. Prevents exploitation of resources for short term gains and targets the long term aims.
2. Ensures equitable distribution of resources.
3. Minimises the harm caused to the environment.
4. Ensures the availability of resources for their use by the future generations in order to fulfil their needs.

Question 2.
With the help of an example show that ‘reuse’ strategy is better than recycling.  (CBSE 2010)
Answer:
Recycling involves use of energy and money whereas no energy is used in ‘reuse’, so reuse is better than recycling.

For example,
The plastic bottles can be recycled by heating them and remoulding them into different shapes. But, this would require the use of energy resources for getting heat required for remoulding plastic. Also, cost of the energy resource will have to be met. Instead of this, the plastic bottles can be reused for different purposes which will save both money and energy.

Question 3.
Prejudice against traditional use of forests areas has no basis. Explain with an example.
Answer:
Local people were not allowed by the Government to use the forests in the traditional ways they had been using for generations. This has led to harmful effects on the sustainability of forests and its resources. A striking example of such case is: Nomadic shepherds used to take their sheep for grazing in the alpine meadows of Great Himalayan Peak during summers. But when they were not allowed to take sheep for grazing, it was seen that grass in the region grew very tall and then fell over preventing fresh growth, which proved harmful for the biodiversity of the region.

Question 4.
Suggest a few useful ways of utilising waste water.  (NCERT Exemplar)
Answer:
Ways of utilising waste water are:

• Ground water level can be recharged.
• Can be used for construction purposes.
• Washing cars and watering gardens by treated waste water.
• Organic wastes in waste water may be used as fertilisers for crops.

Question 5.
What is the importance of forest as a resource?  (NCERT Exemplar)
Answer:
Forest are important as a resources because they

• Provide shelter and food to wildlife.
• Maintain balance of oxygen and carbon dioxide in the atmosphere.
• Increase water holding capacity of soil and prevent soil erosion.
• Help to regulate the water cycle.
• Products like fuel, wood, timber, paper, etc. are obtained.
• Products like fruits, resins, gums, essential oils, etc. used in various industries are obtained.

Question 6.
Why are the Arabari forests of Bengal known to be a good example of conserved forest?  (NCERT Exemplar)
Answer:
Due to efforts of forest officer A.K. Banerjee, the Sal forests in Arabari forests of West Bengal were revived with the active participation of the local people in their conservation. In return the villagers were given employment in both silviculture and harvesting operations, 25 per cent of the final harvest, and allowed fuel wood and fodder collection on payment of a nominal fee.

By 1983, due to the active and willing participation of the villagers, the previously worthless Sal forests in Arabari forest range of Midnapore district Underwent a remarkable recovery and were valued ₹ 12.5 crores.

Extra Questions for Class 10 Science Chapter 16 Value Based Questions

Question 1.
An environmentalist on visit to your school suggested the use of three R’s to save the environment. Explain what he meet by three R’s and how would you follow his advice at home. What values will be evident in this? (CBSE 2009)
Answer:
The three R’s are Reduce, Recycle and Reuse.
Reduce: It means to minimise the use of natural resources.
Recycle: It means to recycle the wastes to obtain materials again for use.
Reuse: It means to use the things again and again instead of throwing them way.

We would follow his advice at home by reducing use of fossil fuels, recycle the non-biodegradable materials and reuse the plastic and glass bottles of jams and pickles.
The values evident are: Awareness, Eco-friendly care for Nature and environment, Scientific aptitude.

Question 2.
Subhash has started the project of constructing his building. His architect suggested that he should add a system of rainwater harvesting in his building. He thought by adopting water harvesting in his project, he can solve his water crisis problem in the years to come.
(i) Is Subhash correct in his approach? Support your answer.
(ii) Give the values shown by Subhash.  (CBSE 2012)
Answer:
(i) Yes, Subhash is correct in adopting water harvesting in his project because the rainwater falling on the roof can be collected and used for recharging the ground water instead of flowing into drains. This would increase the ground water as it neither evaporates nor acts a breeding ground for mosquitoes like the water stored on surface. It also does not get contaminated by the human or animal wastes.

(ii) The values shown by Subhash:

• Scientific aptitude, Decision-Making
• Environment Friendly, Care for Nature.

In this page, we are providing Natural Resources Class 9 Extra Questions and Answers Science Chapter 14 pdf download. NCERT Extra Questions for Class 9 Science Chapter 14 Natural Resources with Answers will help to score more marks in your CBSE Board Exams. https://ncertmcq.com/extra-questions-for-class-9-science/

Class 9 Science Chapter 14 Extra Questions and Answers Natural Resources

Extra Questions for Class 9 Science Chapter 14 Natural Resources with Answers Solutions

Natural Resources Class 9 Extra Questions Very Short Answer Type

Natural Resources Class 9 Extra Questions Question 1.
What are the resources available on Earth for life to exist?
Answer:
Air, water and land are the resources available on the Earth which help life to exist.

Natural Resources Class 9 Important Questions Question 2.
Name the compound of carbon responsible for the ozone hole in the atmosphere.
Answer:
Chlorofluorocarbons (CFC’s) are responsible for the ozone hole in the atmosphere.

Class 9 Science Chapter 14 Extra Questions And Answers Question 3.
State the temperature range on the surface of the moon.
Answer:
The temperature ranges from -190°C to 110°C on the moon

Natural Resources Class 9 Extra Questions And Answers Question 4.
State any one difference between oxygen and ozone.
Answer:
Oxygen is a diatomic molecule with formula 02 whereas ozone is a triatomic molecule-with formula 0₃.

Extra Questions For Class 9 Science Chapter 14 Natural Resources Question 5.
Name the stage in the life cycle of aquatic animals which is affected by a change in temperature.
Answer:
The stage of animals which is affected by the change in the temperature is – the eggs at the hatching stage, the larvae and the young ones of the animals.

Extra Questions Of Natural Resources Class 9 Question 6.
Along with the natural resources available on the Earth, what else is required to meet the basic requirements of all life forms on the Earth?
Answer:
Solar energy is required to meet the basic requirements of all life forms on Earth.

Natural Resources Class 9 Questions And Answers Question 7.
How is biosphere a dynamic and stable system?
Answer:
There is a constant interaction between the biotic and the abiotic components of the global ecosystem (biosphere) which makes it a stable system. The basic composition and the structure of the system do not change while carrying out the various processes. So, it is a stable system.

Natural Resources Extra Questions Question 8.
How do forests play a major role in maintaining the water cycle?
Answer:
The amount of water vapour in the atmosphere is dependent on the transpiration of water from the leaves of the plants present in a forest. Also, the storage of water in watershed is influenced by the forests. So, forests play a major role in maintaining the water cycle.

Ch 14 Science Class 9 Extra Questions Question 9.
Why is step farming done in hills?
Answer:
Step farming is done in hills to prevent soil erosion by slowing down the speed of the water running down the slopes.

Class 9 Natural Resources Extra Questions Question 10.
Why are root nodules useful for plants?
Answer:
The root nodules of leguminous plants contain nitrogen-fixing bacteria like the Rhizobium which help to increase the fertility of the soil by fixing atmospheric nitrogen.

Class 9 Science Ch 14 Extra Questions Question 11.
What are the biotic and the abiotic components of the biosphere?
Answer:

• Biotic component: comprises of living things.
• Abiotic component: comprises of non-living things like temperature, rainfall, air, water and soil.

Questions On Natural Resources Class 9 Question 12.
What percentage of oxygen and nitrogen are present in the atmosphere?
Answer:
The approximate percentage of oxygen and nitrogen in the atmosphere are:
Oxygen: 21%, Nitrogen: 78%

Extra Questions On Natural Resources Class 9 Question 13.
Give the major source of minerals in the soil.
Answer:
The minerals in the soil depend upon the rocks from which the soil is formed. So, the rocks are the major source of minerals in the soil.

Natural Resources Class 9 Important Questions With Answers Question 14.
Name the two gases given out during the burning of fossil fuels which dissolve in rain to form acid rain.
Answer:
Sulphur dioxide and oxides of nitrogen.

Extra Questions Of Chapter Natural Resources Class 9 Question 15.
Name the group of compounds responsible for ozone layer depletion.
Answer:
Chlorofluorocarbons (CFCs) are responsible for ozone layer depletion.

Natural Resources Class 9 Extra Questions Short Answer Type 1

Question 1.
What are the sources of oxygen in the atmosphere?
Answer:
The sources of oxygen in the atmosphere are:

• Oxygen released during photosynthesis by plants
• The dissociation of oxides from their compounds
• The disintegration of ozone in presence of UV rays
• As the water in combined form

Question 2.

1. What causes winds?
2. List any two methods of preventing soil erosion.

Answer:

1. Due to the unequal heating of land and water, the land get heated up faster during the day, the air on land rises up and creates a region of low pressure. As a result, the air over the sea moves towards the region of low pressure formed on the land. This causes winds to flow.

2. (a) Overgrazing by cattle should be avoided.
(b) Large scale afforestation should be done as roots of plants prevent the soil from getting carried away.
(c) Increasing the vegetation cover on the ground reduces the impact of flowing water on soil and prevents it from getting washed away.
(d) Contour farming can be done by ploughing the land in furrows across the natural slope of the land to trap water flowing down.
(e) Step farming is practised in hilly regions which reduce the flow of water and give it more time to percolate into the soil.

Question 3.
List the importance of oxygen gas and ozone gas in the atmosphere.
Answer:
Role of Oxygen gas: It helps in the process of combustion, respiration and formation of many organic compounds.
Role of Ozone: It absorbs the harmful UV rays of the Sun which can cause skin diseases and cancer on reaching the Earth’s surface.

Question 4.
Mention one method by which living organisms influence the formation of soil.
Answer:
The living organisms like lichens and mosses are the initial colonisers of rocks which secrete certain chemical substances that dissolve the minerals of rock and cause the gradual weathering of rocks. The rocks get broken down into small, fine particles of soil. So, living organisms play an important role in the formation of soil.

Question 5.
Explain the occurrence of land breeze in coastal areas.
Answer:
During the day, in coastal regions, the air above land gets heated faster and warm air being lighter rises up thereby creating a region of low pressure. The air over the sea then moves towards the area of low pressure. The movement of air from one region to the other creates winds. At night, water cools down slower than the land, so the air above water would be warmer than the air above land. This causes air over the land to move towards the region of low pressure over water.

Question 6.
What are the two ways in which carbon dioxide is fixed in the environment?
Answer:
Carbon dioxide is fixed in the atmosphere when:

1. Green plants utilise the carbon dioxide and convert it into glucose during photosynthesis.
2. Carbon dioxide dissolved in seawater in the form of carbonates gets used up by the marine animals for the formation of their shells.

Question 7.

1. Why do terrestrial forms require freshwater?
2. Give two examples where freshwater can be found in the frozen form on the Earth.

Answer:

1. The terrestrial organisms require freshwater as they face osmotic problems if kept in marine water because they have low osmotic concentration. In order to maintain the balance of the salts present in their body, freshwater organisms require a medium having less salt concentration i.e., freshwater.
2. Freshwater can be found in a frozen form at polar ice-caps and the glaciers.

Question 8.
What is the role of the atmosphere in climate control?
Answer:
The atmosphere acts as a buffer which checks excessive rise in temperature during the day and prevents excessive cooling of the Earth during the night. The atmosphere helps to keep the average temperature of the Earth steady.

Question 9.
State any two harmful effects of air pollution.
Answer:
The two harmful effects of air pollution are:

1. Respiratory problems and difficulty in breathing
2. Acid rains

Question 10.
1. Define the term ‘smog’.
2. Name any two types of disease caused by regularly breathing polluted air.
Answer:
1. Smog is a kind of air pollution, named for the mixture of smoke and fog in the air. The thick cloud of water droplets having smoke particles suspended in the atmosphere which restricts visibility is called smog.
2. Diseases caused by breathing polluted air are:
(a) Allergy
(b) Respiratory disorders
(c) Heart-related problems

Question 11.
Mention a cause and a consequence of acid rain.
Answer:
Cause of acid rain: The oxides of nitrogen and sulphur like nitrogen dioxide and sulphur dioxide released from the burning of fossil fuels gets mixed with water vapour present in the atmosphere to form acids. These acids dissolve in the rainwater and fall as acid rain on the Earth.

A consequence of acid rain:

1. The fertility of soil gets reduced due to the acidity created in the soil by the acid rains.
2. Acid rain corrodes the historic monuments and structures made of marble, metals, painted surfaces, etc.
3. The aquatic life is also harmed due to excess amount of acids which gets dissolved in water by acid rains.

Question 12.
What is meant by biogeochemical cycle? Name the two essentials which are transferred between different components of the biosphere.
Answer:
The movement of nutrient elements through the various components of an ecosystem i.e., biotic and the abiotic components, is called a biogeochemical cycle.
The two essentials which are transferred between different components of the biosphere are: Matter and energy,

Question 13.
What is the difference between nitrification and denitrification?
Answer:
Nitrification:
The process by which ammonia or ammonium compounds is converted into nitrites by Nitrosomonas and nitrites into nitrates by the Nitrobacter is called nitrification.

Denitrification:
The process by which the nitrites or nitrates are broken down into elemental nitrogen (N₂) by Pseudomonas or Thiobacillus is called denitrification.

Question 14.
Draw a well-labelled diagram to show the carbon cycle in nature.
Answer:

Question 15.
State the role of photosynthesis and respiration in the carbon cycle.
Answer:
Photosynthesis: Carbon dioxide in the atmosphere is fixed by green plants during the process of photosynthesis and converted into glucose.

Respiration: Glucose is oxidised during respiration to obtain energy. Carbon dioxide gets released during the process and is returned to the atmosphere. In this way photosynthesis and respiration help in maintaining the carbon cycle in nature.

Question 16.
Draw a neat labelled diagram to show the nitrogen cycle.

Question 17.
Name any four carbon-containing molecules which are essential for human beings.
Answer:
The carbon-containing molecules essential for human beings are:

1. Deoxyribonucleic acid-DNA
2. Proteins
3. Carbohydrates
4.  Fats

Question 18.
Draw a well-labelled diagram to show the oxygen cycle in nature.
Answer:

Question 19.
(a) Why do terrestrial forms require freshwater?
(b) Mention any two processes involved in the water cycle.
Answer:
(a) Terrestrial forms require water for carrying out the various cellular and metabolic process which occur in their body.
(b) Two processes involved in the water cycle are: Evaporation of water from water bodies and precipitation of water in the form of rain, hail or snow.

Question 20.
What is the importance of greenhouse gases present in the atmosphere?
Answer:
The greenhouse gases like carbon dioxide and methane prevent the escape of heat from the Earth. Thus, these gases play an important role of keeping the average temperature of the Earth constant.

Question 21.
What is the greenhouse effect? What will happen if the concentration of greenhouse gases increase in the air?
Answer:
The phenomenon in which the incoming sunlight is allowed to pass through the atmosphere but heat radiated back from the planet’s surface is trapped by the gases like carbon dioxide, water vapour and methane present in the atmosphere is called the greenhouse effect.

Increase in concentration of greenhouse gases would prevent the escape of heat from the Earth, increase the average temperature worldwide and result in global warming. Global warming will cause a rise in sea and odd climatic changes due to faster melting of glaciers and polar ice caps.

Natural Resources Class 9 Extra Questions Short Answer Type 2

Question 1.
1. The circulation of carbon is important in nature. Give reasons for your answer.
2. Explain any two processes involved in the cycling of nitrogen in the environment.
Answer:
1. The circulation of carbon dioxide is important in nature as it helps in maintaining the balance of carbon dioxide and oxygen in the atmosphere. Carbon dioxide is taken up by plants for photosynthesis and oxygen released during photosynthesis is utilised by the plants and animals for respiration.

Hence, it is necessary to maintain the balance of these gases. Carbon dioxide gas gets cycled between the atmosphere and the living organisms. An excess of carbon dioxide in the atmosphere causes global warming due to the greenhouse effect.

2. The two-process involved in the cycling of nitrogen in the environment are nitrogen fixation and ammonification.

(a) Nitrogen fixation in which the atmospheric nitrogen is converted into nitrites and nitrates which are water-soluble and are easily taken up the roots.

(b) Ammonification: Formation of ammonia due to the decomposition of dead organic matter is called as Ammonification.

Question 2.
State the reason for the following:
1. Excess burning of coal causes the greenhouse effect.
2. Soil is a mixture.
3. Temperature ranges from (-190°C -110°C) on the surface of the moon.
Answer:
1. Carbon dioxide gas is released during the burning of fuel like coal and petroleum. Carbon dioxide has a property due to which it allows rays of the Sun to pass through and reach the surface of the Earth but stops the long-wave infra-red radiations to pass through on being re-radiated from the surface of the Earth. Thus, carbon dioxide traps the heat rays of the Sun and causes the greenhouse effect.

2. Soil is a mixture of minerals, organic matter, gases, liquids, and the various organisms that together support life on Earth.

3. The moon does not have an atmosphere like that on the Earth which traps the heat rays of the Sun and keeps its warm. The atmosphere helps in checking rise in temperature during the day and the fall in temperature during night. So, in spite of being at the same distance from the Sun as the Earth, the temperature on moon ranges from (-190°C-110° C).

Question 3.
With the help of the diagram shows the carbon cycle in nature. What are the two ways in which carbon dioxide is fixed in the environment?
Answer:
The carbon cycle in nature can be depicted by the following diagram:

Carbon dioxide is fixed in the atmosphere by the following two ways:
1. Green plants utilise the carbon dioxide and convert it into glucose during photosynthesis.
2. Carbon dioxide dissolved in seawater in the form of carbonates gets used up by marine animals for the formation of their shells.

Question 4.
Sun as a natural factor helps in the formation of soil. Explain.
Answer:
The Sun helps in soil formation in the following ways:
Rocks expand when they get heated by the Sun during the day. During the night, the rocks cool down and contract. This results in the formation of cracks in the rocks as the rate of expansion and contraction are different. The rocks split and break into smaller pieces.

Question 5.
What is the percentage of oxygen in the atmosphere? Name any two compounds of oxygen found in nature. Name any three processes by which oxygen is used up in the atmosphere.
Answer:
The percentage of oxygen in the atmosphere is approximately 21%.
The diatomic form oxygen (O₂) and the triatomic form ozone (O₃) are the two forms in which oxygen is found in nature.
The three processes by which oxygen is used up in the atmosphere are:

• Combustion of fossil fuels.
• Respiration by living organisms.
• Decomposition of organic matter.
• Formation of oxides during fixation and other chemical reactions.

Question 6.
How is the greenhouse effect related to global warming? Explain.
Answer:
The phenomenon in which the incoming sunlight is allowed to pass through the atmosphere but heat radiated back from the planet’s surface is trapped by the gases like carbon dioxide, water vapour and methane present in the atmosphere is called the greenhouse effect.

An increase in the percentage of greenhouse gases like carbon dioxide and methane prevents the escape of heat from the Earth. So, the greenhouse effect is responsible for the increase in average temperature worldwide and is causing global warming. Global warming leads to melting of glaciers and polar ice caps at a faster rate which causes a rise of the sea and other odd climatic changes.

Question 7.
Why is water necessary for the living organisms?
Answer:
Water is necessary for living organisms because:

• All cellular metabolic processes occur in the water medium.
• The transportation of various substances from one part of the body to another occurs in dissolved form in water.
• All the reactions taking place in the cells or in our body occur between substances which are dissolved in water.

Question 8.
How are various biological factors needed for soil formation?
Or
Which symbiotic life forms can grow on stones and help in the formation of soil? Write the model of their action for making soil from rocks.
Answer:
Lichens are the symbiotic association of algae and fungi. Lichens help in the formation of soil. The living organisms like lichens and mosses are the initial colonisers of the rocks which secrete certain chemical substances which dissolve the minerals of rock and cause the gradual weathering of rocks. The rocks get broken down into small, fine particles of soil. So, biological factors play an important role in the formation of soil.

Question 9.
What is topsoil? Mention two factors that decide which plants will thrive on that soil.
Answer:
Topsoil refers to the topmost layer of the soil which contains humus, soil particles and living organisms.
The two factors that decide which plants will thrive on that soil are:

• The humus content and the type of microbes present in the soil.
• The size and texture of soil particles along with the composition of the soil.

Question 10.
What are the causes of soil erosion?
Answer:
The causes of soil erosion are:

1. Large scale deforestation
2. Large scale overgrazing
3. Industrialisation
4. Urbanisation
5. The land left uncultivated for a long time
6. Mining and other human activities which lead to loss of topsoil

Question 11.
Rivers from land, add minerals to seawater. Discuss how.
Answer:
Yes, it is true because water has the ability to dissolve a large number of substances. When the river water flows over the rocks containing soluble minerals, some of the minerals from the rocks get dissolved in the water. These minerals are carried away by the river water into the sea. Thus, the nutrients from the land are carried away by the river into the sea.

Question12.
How can we prevent the loss of topsoil?
Answer:
The loss of the topsoil can be prevented by the following ways:

1. Overgrazing by cattle should be avoided.
2. Large scale afforestation should be done as roots of the plants prevent the soil from getting carried away.
3. Increasing the vegetation cover on the ground reduces the impact of flowing water on soil and prevents it from getting washed away.
4. Contour farming can be done by ploughing the land in furrows across the natural slope of the land to trap water flowing down.
5. Step farming is practised in hilly regions which reduces the flow of water and gives it more time to percolate into the soil.

Question 13.
How is the life of organisms living in water affected when water gets polluted?
Answer:
When the water gets polluted, the life of organisms living in water gets affected in the following ways:

1. The domestic wastewater contains detergents and nutrients which increase the growth of aquatic plants, algae, etc., and reduces the amount of dissolved oxygen in the water body. This adversely affects the aquatic animals as they die due to scarcity of oxygen.
2. The fertilisers, pesticides, etc., which get washed into the water body from the agricultural fields also harm the aquatic organisms.
3. Many disease-causing organisms are also released in the domestic wastewater which acts as a source of many water-borne diseases like cholera.
4. The heated water released directly into the water bodies by some industries can cause the death of aquatic organisms which are not able to tolerate the sudden change in temperature.
5. The heavy metals dissolved in polluted water is also harmful to the living organisms.

Question 14.
During summer, if you go near the lake, you feel relief from the heat, why?
Answer:
We feel relief from the heat when we go near a lake during summer because:
1. The Sunrays heat the land near the lakes more quickly than the water of the lake. The hot air rises up to create a region of low pressure on the land. Evaporation of the water causes cooling of the air above the lake and this cool air flows from the lake towards the region of low pressure on the land. The cool air gives relief to us from the heat.

Question 15.
In the coastal area, wind current moves from the sea towards the land during the day; but during the night
Answer:
During the day, in the coastal regions, the air above the land gets heated faster and the warm air being lighter rises up thereby creating a region of low pressure. The air over the sea then moves towards the area of low pressure. The movement of air from one region to the other creates winds. At night, water cools down slower than the land, so the air above the water would be warmer than the air above land. This causes air over the land to move towards the region of low pressure over water.

Question 16.
Following are a few organisms
(a) lichen
(b) mosses
(c) mango tree
(d) cactus.
Which among the above can grow on stones; and also help in the formation of soil? Write the model of their action for making soil.
Answer:
Lichens and the mosses can grow on stones and help in the formation of soil. The chemical substances secreted by the living organisms like lichens and mosses degrade the rocks and convert them into fine particles of soil. They also cause crevices and cracks in the rocks which help in the colonisation of rocks by bigger plants. The roots of these plants widen the cracks and cause the breakdown of large rocks.

Question 17.
Soil formation is done by both abiotic and biotic factors. List the names of these factors by classifying them as abiotic and biotic?
Answer:
The abiotic factors involved in soil formation are: Sun, water, wind.
The biotic factors involved in soil formation are: lichens, mosses and trees, microorganisms, etc.

Question 18.
All the living organisms are basically made up of C, N, S, P, H and O. How do they enter the living forms? Discuss.
Answer:
Elements like C, N, S, P, H and O enter the living forms through the process of photosynthesis and on getting absorbed from soil by the plants and living organisms.

Question 19.
Why does the percentage of gases like oxygen, nitrogen and carbon dioxide remain almost the same in the atmosphere?
Answer:
The biotic and the abiotic components of the biosphere interact with each other and continuously cycle the elements like nitrogen, oxygen and carbon through their respective cycles called as biogeochemical cycles. This helps to maintain the percentage of these gases almost constant in the atmosphere.

Question 20.
Why does the moon have very cold and very hot temperature variations e.g., from -190°C to 110°C even though it is at the same distance from the Sun as the Earth is?
Answer:
The moon does not have an atmosphere due to which very cold and very hot temperature variations from -190°C to 110°C occur on its surface. The atmosphere helps in maintaining the temperature as it prevents the excessive rise in temperature during daytime and prevents excessive cooling during the night by trapping heat energy of the Sun.

Question 21.
Why do people love to fly kites near the seashore?
Answer:
The wind blows from the sea towards the land during the daytime which helps in flying the kite higher. Also, the wind coming from the sea is cooler which makes the kite flyers feel comfortable. So, people love to fly kites near the seashore.

Question 22.
Why does Mathura refinery pose problems to the Taj Mahal?
Answer:
The harmful gases like sulphur dioxide released from the Mathura oil refinery get mixed with the water vapour present in the air and form acids like sulphuric acid. This acid falls along with the rains in the form of acid rain. The acid present in the acid rain is causing the corrosion of the marble used in the Taj Mahal. The colour (yellowing of marble was caused), as well as the quality of the marble, was getting degraded due to the acid rains. Thus, Mathura refinery posed a problem to the Taj Mahal.

Question 23.
Why do lichens not occur in Delhi whereas they commonly grow in Manali or Darjeeling?
Answer:
Lichens are bio-indicators as they help in assessing the level of pollution in the environment. They are highly sensitive to the gaseous pollutants like sulphur dioxide released from the vehicles and other sources. Delhi has a large number of vehicles and the industries which emit these gases compared to Manali or Darjeeling. So, lichens are unable to grow in Delhi.

Question 24.
Why does water need conservation even though large oceans surround the landmasses?
Answer:
The freshwater resources like river, ponds, lake, etc., are not evenly distributed on the Earth. Most part of the Earth is covered by the oceans and seas which have marine water (salty water) which is not fit for human consumption. So, there is a need to conserve the freshwater resources and the water available to us.

Question 25.
There is a mass mortality of fishes in a pond. What may be the reasons?
Answer:
The mass mortality of fishes in a pond can be the result of one or more of the following factors:

1. Thermal pollution due to the heated water directly released into the water body which harms the organisms that are not able to withstand the sudden change in temperature.
2. The release of heavy metals, poisonous substances like mercury or other harmful chemicals into the waterbody.
3. Blockage of the gills of the fishes by the pollutants or the suspended particles released into the waterbody.
4. Harmful pesticides or chemicals washed into the waterbody from the agricultural fields.
5. Toxic wastes released into the water by the industries.

Question 26.
Lichens are called pioneer colonisers of bare rock. How can they help in the formation of soil?
Answer:
The chemicals released by the lichen cause the gradual weathering of the large particles of rock into smaller fine particles of soil. Thus, they help in the formation of soil.

Question 27.
“Soil is formed by water.” If you agree to this statement then give reasons.
Answer:
Yes, water helps in the formation of soil as it helps in the breakdown of large rocks into fine particles of soil by the following two ways:

1. The water enters the cracks and crevices in the rocks, gets unevenly heated by the Sun and when it expands during freezing in the winter season, the rocks break down in smaller pieces.
2. Also, the fast running water over the surface of the rocks causes weathering of rocks to form soil.

Question 28.
Fertile soil has lots of humus. Why?
Answer:
Fertile soil has a lot of hummus because

1. Soil particles are bound in the form of crumbs by the humus which helps the soil in aeration as well as hydration.
2. Humus contains many kinds of minerals dissolved in it.
3. Growth of the plants is enhanced by the various chemicals present in humus.
4. Soil becomes porous due to humus which facilitates the penetration of roots into the soil.

Question 29.
Why is step farming common in hills?
Answer:
Step farming is practised in hilly regions which reduce the flow of water or the rainwater and gives it more time to percolate into the soil.

Question 30.
Why are root nodules useful for the plants?
Answer:
The plants called legumes to harbour the nitrogen-fixing bacteria like Rhizobium in their roots in the form of root nodules. These bacteria convert the atmospheric nitrogen into nitrites or nitrates which can be assimilated by plants.

Natural Resources Class 9 Extra Questions Long Answer Type

Question 1.
1. Make a neat and labelled sketch of the nitrogen cycle in nature.
2. Describe in brief the role of nitrogen-fixing bacteria and lightning in fixing nitrogen.
Answer:
1. The nitrogen cycle is:

2. The atmospheric nitrogen can be fixed in the following ways:
By nitrogen-fixing bacteria: The nitrogen-fixing bacteria live either in a symbiotic association like the Rhizobium in the root nodules of the legumes or live freely like Azotobacter. The bacteria fix the atmospheric nitrogen into nitrates which are absorbed by the plants in soluble form and assimilated in their body.

By lightning: Lightning has enormous energy which breaks nitrogen molecules and enables their atoms to combine with oxygen present in the air to form nitrogen oxides. These oxides dissolve in rain, form nitrates and are carried to the Earth with the rains.

Question 2.
Explain the role of the atmosphere as a blanket. List the factors deciding the rainfall patterns.
Answer:
The atmosphere is a blanket of air around the Earth which acts as a buffer to prevent the excessive or
sudden rise of temperature during the day and also prevents excessive cooling of the Earth during the night. It slows down the escape of heat into the outer space during the night.

Thus, the atmosphere helps to keep the average temperature of the Earth fairly steady during the day and also during the whole year. The prevailing wind patterns decide the rainfall patterns. The South-West monsoon and the North-East monsoon cause rains in large parts of India.

Question 3.
1. Many municipal corporations are trying water harvesting to improve the availability of water. Give reason.
2. Rainwater sometimes contains traces of acid. Why? Explain in brief.
Answer:
1. The Municipal Corporations are trying water harvesting in order to recharge the underground water reservoirs and the underground water level. This ensures the availability of water during the scarcity of rainfall or water. Rainwater harvesting involves the collection of water from surfaces on which rain falls and stores this water for later use. Generally, the water is collected from the roofs of buildings and stored in rainwater tanks.

2. Combustion of fossil fuels releases oxides of nitrogen (NO₂) and sulphur (SO₂) which dissolve in rainwater to form their respective acids. These acids then fall along with rains and such rain is called acid rain. Due to the presence of such acids, the rainwater sometimes contains traces of acids.

Question 4.
How does the addition of undesirable substances and change in temperature affect water life?
Answer:
Addition of undesirable substances affects the water life in the following ways:

1. Addition of harmful chemicals or metals like mercury, lead, etc., cause poisoning of water bodies and harm aquatic organisms.
2. The pathogens released into the water bodies are the cause of many human diseases like cholera, typhoid, etc.
3. Aquatic organisms are harmed and even killed due to deficiency of oxygen which occurs when the addition of sewage, fertilisers and nutrients in the water body resulting in excessive growth of algae. The algae drain out the oxygen from the water body.

The change in temperature can also affect water life because:

1. The variation in temperature affects the breeding patterns of aquatic animals.
2. The hatching of the eggs is adversely affected due to the changes in the temperature of the water.

Question 5.
What are the various factors or the processes that make soil?
Answer:
Soil is formed due to various physical, chemical and biological processes which result in the breakdown of rocks into fine particles of soil over millions of years. The formation of soil occurs due to factors and processes like Sun, water, wind, living organisms and lichens.

1. Sun: Rocks expand when they get heated by the Sun during the day. During the night, the rocks cool down and contract. This result in the formation of cracks in the rocks as the rate of expansion and contraction are different. The rocks split and break into smaller pieces.

2. Water: Water acts in two ways to break the large rocks into small pieces. Water enters the cracks and crevices in the rocks, gets unevenly heated by the Sun and when it expands during freezing in the winter season, the rocks break down into smaller pieces. Also, the fast running water over the surface of the rocks causes weathering of rocks to form soil.

3. Wind: The winds carry small rocks and sand from one place to another and these strong winds rub against the large rocks to erode them.

4. Living organisms (Lichens): The chemical substances secreted by the living organisms like lichens degrade the rocks and convert them into fine particles of soil.

Question 6.
How do fossil fuels cause air pollution?
Answer:
Fossil fuels like coal and petroleum produce oxides of nitrogen and sulphur on combustion. These gases react with water vapour present in the air to form acids which fall down along with rains on the Earth. Acid rain is very harmful to the plants, animals and the microorganisms present in the soil. Also, the suspended particulate matter released on the burning of fossil fuels cause respiratory problems to human beings and reduces visibility when it forms smog.

Question 7.
What are the causes of water pollution? Discuss how you can contribute in reducing water pollution. Ans. Addition of undesirable and harmful substances in water or the removal of useful substances from water
is referred to as water pollution. It is caused due to:

1. Addition of fertilisers and pesticides washed away from the agricultural field into the nearby water bodies.
2. Disposal of domestic sewage into the waterbody like rivers.
3. The death of many aquatic organisms occurs when hot water from the industries is directly released into the water body. This also reduces the amount of dissolved oxygen in the waterbody.
4.  Washing of the clothes in the waterbody using detergents.
5. Many harmful radioactive substances released from the industries dumped into the waterbody.

Water pollution can be reduced by the following measures:

1. The sewer lines should not be directly connected to the waterbody.
2. Disposal of garbage and wastes into the waterbody should not be allowed.
3. Toxic compounds released from the industries should not be dumped in the water bodies.
4. Detergents increase the nutrient content of water which is harmful to aquatic organisms as the amount of dissolved oxygen gets reduced in water due to excessive algal growth. Therefore water containing detergents should not be allowed to run off into water bodies.
5. Trees should be planted near the banks of the river to prevent soil erosion which leads to siltation in the water bodies.

Question 8.
A motor car, with its glass totally closed, is parked directly under the Sun. The inside temperature of the car rises very high. Explain why.
Answer:
Glass has a property due to which it allows the radiations of the Sun to pass through and enter the car. Infrared radiations also enter the car along with other radiations. Glass is transparent to infrared. radiation from the Sun having smaller wavelength but opaque to longer wavelength radiations that are emitted by the interior of the car.

The infrared radiations get re-radiated by upholstery and other inner parts of the car but cannot pass out of the glass like the other radiations. So, the heat trapped inside raises the temperature inside the car.

Question 9.
Justify “Dust is a pollutant”.
Answer:
Dust can be considered as a pollutant because:

1. Suspended particles are present in the dust which can enter the respiratory systems of the organisms and can cause asthma, bronchitis, allergies or other respiratory diseases.
2. When dust falls on the leaf surface, it can cause blocking of the stomata which adversely affects the process of photosynthesis and plant growth.
3. Many heavy metals and toxic compounds are present in the dust which can harm living organisms.
4. Dust can be harmful to the eyes of the organism as irritation and reddening of eyes can be caused due to it.

Question 10.
Explain the role of the Sun in the formation of soil.
Answer:
The Sun helps in soil formation in the following ways:
Rocks expand when they get heated by the Sun during the day. During the night, the rocks cool down and contract. This result in the formation of cracks in the rocks as the rate of expansion and contraction are different. The rocks split and break into smaller pieces.

Question 11.
Carbon dioxide is necessary for plants. Why do we consider it as a pollutant?
Answer:
Carbon dioxide is necessary for the plants, as it is utilised during the process of photosynthesis. It acts as a raw material for photosynthesis and helps in maintaining the temperature on the Earth. If the concentration of carbon dioxide increases in the atmosphere above a certain level, it traps more heat of the Sun because it is a greenhouse gas.

This ultimately results in an increase in the average temperature on Earth and causes global warming. Due to higher temperatures, the polar ice caps, glaciers and the snow of mountains melt faster. This can lead to floods and an increase in seawater level. So, carbon dioxide is considered a pollutant.

Natural Resources Class 9 Extra Questions HOTS

Question 1.
What is the fate of the glucose molecules formed in photosynthesis?
Answer:
The glucose molecules formed during photosynthesis are either stored in the form of starch in the green plants or get transported in the form of sucrose to the various parts of the plant. Glucose is also utilised by the plants during respiration to obtain energy.

Question 2.
What is the likely outcome if all the oxygen in the environment gets converted into ozone?
Answer:
If all the oxygen in the environment gets converted into ozone it will be harmful to the living organisms as ozone adversely affects the living organisms and would eventually kill them.

Question 3.
We are lucky that ozone is not stable near the Earth’s surface. Why?
Answer:
The ozone present in the lower atmosphere is called ‘bad ozone’ as it adversely affects the living organisms, corrodes metals, acts as a greenhouse gas and creates respiratory problems in animals. So, we are lucky that ozone is not stable near the Earth’s surface as it gets converted into oxygen or the various oxides.

Question 4.
1. Nitrogen-fixing bacteria are usually found only in the root nodules of leguminous plants. Why?
2. Name a non-leguminous plant which has nitrogen-fixing bacteria in root nodules and the microbe present in it.
Answer:
1. The nitrogen-fixing bacteria are usually found only in the leguminous plants as the roots of the leguminous plants provide shelter and the specific conditions required for such bacteria. The bacteria like Rhizobium live in symbiotic association with the roots of leguminous plants.

2.  Alnus is a non-leguminous plant which has a nitrogen-fixing bacteria called Frankia in its root nodules.

Question 5.
What will be the consequences if all the decomposers are removed from the Earth?
Answer:
Decomposers play a vital role in the recycling of various nutrients. The recycling of the nutrients would be hindered in the absence of decomposers. They also help in the decomposition of dead plants, animals and organic matter. In the absence of decomposers, the Earth would get covered by the remains of such organisms and it would become difficult for the organisms to survive on Earth.

Question 6.
Excessive use of pesticides in the fields can adversely affect the fishes living in the nearby ponds. How?
Answer:

• The pesticides used in the fields can get washed into the nearby water bodies by the rains and flowing water.
• These pesticides cause a phenomenon called biological magnification which adversely affects the fishes of the pond.

Question 7.
Excess use of fertilisers in the field is not advisable to the farmers. Give reasons.
Answer:
Excess use of fertilisers increases the food production for a short term but in the long term, it is not advisable to the farmers because
1. Excess use of fertilisers increases the salinity of the soil and reduces its fertility.
2. The fertilisers can get washed away into the nearby ponds where they cause excessive growth of algae due to nutrient enrichment. This depletes the dissolved oxygen from the water body and harms the other aquatic organisms.

Question 8.
The public transport like buses and the autos have shifted to CNG instead of petrol or diesel in Delhi. Why?
Answer:
The public transport like the buses and the autos have shifted to CNG instead of petrol or diesel in Delhi because the gases released from these vehicles cause a lot of pollution and harms the environment in following ways:

• The oxides of nitrogen and sulphur released from the vehicles result in acid rains which is harmful to the living organisms.
• The harmful gases from the exhaust result in several problems like asthma, respiratory disorders, cancer, etc.

Question 9.
Discharge of sewage into the water body decreases the amount of oxygen dissolved in water. How?
Answer:
The sewage water consists of a lot of organic matter which is decomposed by the microorganisms present in the water body. The microorganisms multiply at a rapid rate and consume a lot of dissolved oxygen in order to decompose the organic matter. This reduces the amount of dissolved oxygen in the water.

Question 10.
What will be the result if all the plants get eliminated from the Earth?
Answer:
Plants perform photosynthesis and release oxygen during the process which is used by the other organisms for survival. If all the plants become extinct, eventually all the oxygen requiring living organisms including us will get eliminated from the Earth.

Natural Resources Class 9 Extra Questions Value Based (VBQs)

Question 1.
Vijay is the son of a rich businessman. He lives in a very big house. He always insists and reminds the family members to switch off lights, fans, TVs, etc., of rooms when there is no one in the room, so that use of electricity is minimum. He realises that power generation on a large scale in thermal power plants produces a lot of carbon dioxide and fly ash.
Read the given passage and answer the following questions:

1. How is carbon dioxide responsible for global warming?
2. What measures will you take to reduce levels of carbon dioxide?
3. What values are displayed by Vijay in his action and thoughts?

Answer:
1. Carbon dioxide has a property due to which it allows rays of Sun to pass through and reach the surface of the Earth but stops the rays from being re-radiated from the surface of Earth. The heat of the Sun rays gets trapped by carbon dioxide in this way and causes global warming.
2. The levels of carbon dioxide can be reduced in the atmosphere by increasing the efficiency of engines of vehicles, large scale afforestation, reducing the emission of carbon dioxide from the industries and using alternative sources of energy in place of fossil fuels.
3. The values shown by Vijay are a concern for the environment, intelligence, awareness and scientific attitude.

Question 2.
Due to the establishment of a petroleum refinery near the city, many people started suffering from respiratory problems and the marble used in their houses turned yellow. A survey carried out by Arpit and his colleagues attributed this to the gases released from the refinery. They consulted the Government agencies and suggested to shift the refinery away from the city.
Based on the above, answer the following questions:

1. What can be the reason behind the yellowing of marble?
2. What are the various harmful effects of air pollution?
3. What values are depicted by the efforts of Arpit and his colleagues?

Answer:

1. The oxides of nitrogen and sulphur released from the petroleum refinery dissolve in rainwater to form acids and fall on the Earth. When this acid rain falls on marble it causes yellowing of the marble.
2. The other harmful effects of air pollution are:
   (a) Formation of smog which harms living organisms.
   (b) Respiratory problems, bronchitis, asthma, cancer, etc.
3. The values depicted by Arpit and his colleagues are scientific aptitude, care for the environment and a responsible citizen.

Question 3.
Amrita saw that the farmers of her village use excessive fertilisers and pesticides on their crop. She searched the internet for the effect of such action on the environment. She came to know that their excessive use is harmful to the environment. She talked to the Head of the village and the farmers were motivated to use fertilisers and pesticides judiciously. They were also motivated to practice organic farming for better crop yield.
Based on the above, answer the following questions:
1. How is excessive use of fertilisers and pesticides harmful to the environment?
2. What is organic farming?
3. What values are shown by Amrita in solving the problem?
Answer:
1. The fertilisers and the pesticides get washed away into the nearby water bodies with rainwater or the flowing water.
Excess use of fertilisers causes uncontrolled growth of algae in water bodies which depletes the dissolved oxygen in the water and causes death other aquatic organisms. Excess use of pesticides causes biological magnification which leads to death of many fishes in the water bodies.
2. Organic farming is a method of crop production in which no chemical pesticides or fertilisers are used during the cultivation of crops.
3. The values shown by Amrita are curiosity, inquisitive nature, care for the environment and scientific attitude.

Question 4.
Zeenat and her sister were very happy when their father brought home a new refrigerator. She saw a sticker pasted on the refrigerator which read ‘CFC free’. She asked her father about it. Her father told her that the compounds called CFC are the cause of the ozone hole and so they are not used in the refrigerators to save our environment.
Read the above passage and answer the following:

1.  What is ozone and why is it important?
2. What are CFCs and why are they harmful?
3. What values are shown by Zeenat and her father?

Answer:

1. Ozone is a triatomic molecule of oxygen with formula 03. It traps the harmful rays of the Sun and protects the living organisms.
2. The CFCs are the carbon compounds having both fluorine and chlorine which are very stable and not degraded by any biological process. They persist in the atmosphere and degrade the ozone layer.
3. The quality shown by Zeenat is a curious nature. Her father shows the values of concern for the environment, patience and imparting right knowledge to children.

Question 5.
A farmer came for a consultation with Rajni who worked as ‘Kisan Mitra’ in the village. He told her that he was growing leguminous crop in the field, so what will by the right amount of nitrogenous fertilisers required in his field? Rajni told him that since he was growing leguminous crops in the field, he does not require adding more nitrogenous fertilisers in the field. She further suggested him to grow the leguminous crop alternately with maize or wheat.
Based on the above, answer the following questions:
1. Why did Rajni advise the farmer not to add more nitrogenous fertilisers in his field?
2. Why did she suggest him to grow leguminous crop alternately with maize or wheat?
3. What values are shown by Rajni?
Answer:
1. Rajni advised the farmer not to add more nitrogenous fertilisers as the leguminous plants which the farmer had sown in the field have root nodules which contain nitrogen-fixing bacteria. These nitrogen-fixing bacteria fix the atmospheric nitrogen and give it to the plant, so no additional nitrogen-containing fertilisers are required in the field.

2. Rajni advised the farmer to grow leguminous crop alternately with maize or wheat as the nutrients are taken up by the wheat or maize from the soil will be restored by the nitrogen-fixing bacteria present in the root nodules of the leguminous crop. In this way, the fertility of the soil will be restored and enriched again by the leguminous crop. The process is called crop rotation.

3. The values shown by Rajni are patience, knowledge, proper decision making, scientific aptitude, concern for the environment

In this page, we are providing The Fundamental Unit of Life Class 9 Extra Questions and Answers Science Chapter 5 pdf download. NCERT Extra Questions for Class 9 Science Chapter 5 The Fundamental Unit of Life with Answers will help to score more marks in your CBSE Board Exams. https://ncertmcq.com/extra-questions-for-class-9-science/

Class 9 Science Chapter 5 Extra Questions and Answers The Fundamental Unit of Life

Extra Questions for Class 9 Science Chapter 5 The Fundamental Unit of Life with Answers Solutions

The Fundamental Unit of Life Class 9 Extra Questions Very Short Answer Type

The Fundamental Unit Of Life Class 9 Extra Questions And Answers Question 1.
What process is involved in the movement of O₂ in and out of the cell?
Answer:
Diffusion.

Fundamental Unit Of Life Class 9 Extra Questions Question 2.
Which process is involved in the movement of water from outside into the cell?
Answer:
Osmosis.

Extra Questions For Class 9 Science Chapter 5 With Answers Question 3.
Mention the process by which CO₂ and water move in and out of the cell.
Answer:
Movement of CO₂ occurs by diffusion whereas that of water occurs by osmosis.

Class 9 Science Chapter 5 Extra Questions And Answers Question 4.
Who discovered cells in living organisms? Give an example of a unicellular organism.
Answer:
A.V. Leeuwenhoek observed the.cells in living organisms. Example of a unicellular organism is Amoeba, Paramoecium, etc.

Class 9 Fundamental Unit Of Life Extra Questions Question 5.
Give two examples of prokaryotic organisms.
Answer:
All the bacteria and cyanobacteria are prokaryotic. Example: Nostoc, Oscillatoria, etc.

Fundamental Unit Of Life Extra Questions Question 6.
Name the plastid which stores starch, oils and protein granules.
Answer:
Leucoplast

The Fundamental Unit Of Life Extra Questions Question 7.
List the constituents of plasma membrane.
Answer:
The plasma membrane is composed of lipids and proteins.

Class 9 Science Ch 5 Extra Questions Question 8.
Where do lipids and proteins constituting the cell membrane get synthesised?
Answer:
The lipids are synthesised in smooth endoplasmic reticulum (SER) and the proteins are synthesised in the rough endoplasmic reticulum (RER).

Chapter 5 Science Class 9 Extra Questions Question 9.
Name two unicellular organisms.
Answer:
Amoeba and Paramoecium are unicellular organisms.

Ch 5 Science Class 9 Extra Questions Question 10.
Name the process by which unicellular freshwater organisms and most plant cells tend to . gain water.
Answer:
Endosmosis.

The Fundamental Unit of Life Class 9 Extra Questions Short Answer Type 1

The Fundamental Unit Of Life Class 9 Extra Questions And Answers Ncert Question 1.
Why is plasma membrane called selectively permeable membrane?
Answer:
Plasma membrane is called selectively permeable because it prevents the entry of some substances and allows the entry and exit of only some substances.

Class 9 Chapter 5 Science Extra Questions Question 2.
Define osmosis.
Answer:
The spontaneous movement of water molecules from a region of its high concentration to the region of its low concentration through a selectively permeable membrane is called osmosis.

Ncert Class 9 Science Chapter 5 Extra Questions Pdf Question 3.
What is membrane biogenesis?
Answer:
Some proteins and lipids made by smooth endoplasmic reticulum (SER) help in building the cell membrane of the cell and this process of making of plasma membrane is known as membrane biogenesis.

Ncert Class 9 Science Chapter 5 Extra Questions Question 4.
Why are mitochondria are referred to as strange organelles?
Answer:
Mitochondria are referred to as strange organelles as they have their own DNA and ribosomes so and can make some of their own proteins.

Class 9 Ch 5 Science Extra Questions Question 5.
What is the function of Golgi body?
Answer:
The functions of Golgi body are: storage, modification and packaging of products in vesicles and the formation of lysosomes.

Class 9 Science Chapter 5 Extra Questions Question 6.
(i) In what form do mitochondria release energy? Write its full form.
(ii) The inner membrane of mitochondria is deeply folded. What is the advantage of these folds?
Answer:
(i) The energy is released by mitochondria in form of ATP. Full form of ATP is adenosine triphosphate.

(ii) The folds present on the inner membrane of mitochondria help to provide a large surface area for the ATP generation reactions.

Class 9 The Fundamental Unit Of Life Extra Questions Question 7.
Give three differences between plasma membrane and the cell wall.
Answer:
Plasma Membrane:

• It is the outermost covering of the cell which separates the contents of the cell from its external environment.
• It is mainly composed of lipids and proteins.
• It is living, thin and elastic.

Cell Wall:

• It is a rigid outer covering which lies outside the plasma membrane.
• It is made of cellulose which provides structural strength to plants.
• It is non-living and rigid.

Extra Questions Of Fundamental Unit Of Life Question 8.
Differentiate between nucleus and nucleoid.
Answer:
Nucleus:

• It has a well defined nuclear membrane around it.
• It has chromatin network and contains more than one chromosome.

Nucleoid:

• It lacks a nuclear membrane.
• It has a single chromosome only.

Extra Questions For Class 9 Science Chapter 5 Question 9.
Write two statements to show that lysosomes are called as suicidal bags of the cell.
Answer:
Lysosomes are called as the suicidal bags of the cell as:

1. They contain hydrolytic enzymes which can breakdown the organic material.
2. If the cell gets damaged during disturbance in cellular metabolism, the lysosomes may burst and its enzymes digest their own cell.

Question 10.
Describe the structure of mitochondria with special reference to its membrane covering.
Answer:
Mitochondrion is a double-membrane structure whose outer membrane is very porous while the inner membrane is deeply folded to form cristae. Cristae are folds which create a large surface area for ATP- generating chemical reactions.

The Fundamental Unit of Life Class 9 Extra Questions Short Answer Type 2

Question 1.
Describe an activity to demonstrate endosmosis and exosmosis. Draw a diagram also.
Answer:
Put dried raisins or apricots in plain water and leave them for some time. Then place them into a concentrated solution of sugar or salt. You will observe the following:

(a) Each of the raisins or apricots gains water and swells when placed in water.
Reason: The raisins or apricots swell up as water moves inside them from outside because the water concentration is less inside the cell as compared to the solution outside. Hence, water moves inside the cell by endosmosis.

(b) However, when placed in the concentrated solution they lose water, and consequently shrink.
Reason: The raisins or apricots shrink as water moves outside from them because the water concentration is more inside the cell as compared to the solution outside. Hence, water moves out of the cell by exosmosis.

Question 2.
Differentiate between diffusion and osmosis. Write any two examples where a living organism uses osmosis to absorb water.
Answer:
Diffusion – The movement of a substance from a region of its high concentration to the region of its low concentration is called diffusion.

Osmosis – The spontaneous movement of water molecules from a region of its high concentration to the region of its low concentration through a selectively permeable membrane is called osmosis.

Examples where a living organism uses osmosis to absorb water are:

• Roots of plants absorb water by osmosis.
• Unicellular organisms like Amoeba absorb water by osmosis.

Question 3.
Differentiate between a prokaryotic and eukaryotic cell.
Answer:
Prokaryotic cell:

• Organisms whose cells lack a well defined nuclear membrane.
• They lack membrane bound cell organelles.
• Size is generally small (1-10 pm).
• Have a single chromosome.

Eukaryotic cell:

• Organisms with cells having a well defined nuclear membrane.
• They have membrane bound cell organelles.
• Size is generally large (5-100 pm).
• Have more than one chromosome.

Question 4.
Which organisms are called as the (i) powerhouse of the cell (ii) suicide bags of the cell (iii) kitchen of the cell?
Answer:

• Mitochondria
• Lysosomes
• Chloroplasts

Question 5.
(a) What would happen to the life of the cell if there was no Golgi apparatus?
(b) Which cell organelle detoxifies poisons and drugs in the liver of vertebrates?
Answer:
(a) If there was no golgi apparatus, then the following processes carried out by it would get affected:

• The storage, modification and packaging of products in vesicles.
• The packaging and dispatch of the material synthesised near the ER to various targets inside and outside the cell.
• The formation of lysosomes.
• The formation of cell plate during cell division.

So, in the absence of the Golgi apparatus, most of the functions of the cell would get disrupted.

(b) Smooth endoplasmic reticulum helps to detoxify poisons and drugs in the liver of vertebrates.

Question 6.
What are the functions of the Golgi apparatus?
Answer:
The Golgi apparatus is an important cell organelle as it performs several functions in the cell.

1. Its functions include the storage, modification and packaging of products in vesicles.
2. Golgi apparatus packages and dispatches the material synthesised near the ER to various targets inside and outside the cell.
3. It is also involved in the formation of lysosomes.

Question 7.
What types of enzymes are present in the lysosomes? What is their function? Which cell organelle manufactures these enzymes?
Answer:
Lysosomes are membrane-bound sacs filled with hydrolytic and digestive enzymes. They help to keep the cell clean by digesting any foreign material as well as worn-out cell organelles. Rough endoplasmic reticulum (RER) manufactures these enzymes.

Question 8.
What are chromoplasts and leucoplasts? Give an example of chromoplast which has green pigment.
Answer:
The coloured plastids which have pigments of different colours are called chromoplasts. The colourless plastids which help to store starch, oils or protein granules are called leucoplasts. The green coloured plastid is called chloroplast and it contains a green coloured pigment called chlorophyll.

Question 9.
Write the functions of:
(i) Inner membrane of mitochondria
(ii) Nucleus of the cell
(iii) Ribosomes present in active cells.
Answer:
The functions are:
(i) Inner membrane of mitochondria are the site for the formation of ATP.

(ii) Nucleus of the cell are the control centre of the cell as it controls all the activities of the cell, plays a central role in cellular reproduction and contains DNA which helps to transfer the genetic information from parents to their offsprings.

(iii) Ribosomes present in active cells are the sites for protein synthesis.

Question 10.
What are the different types of endoplasmic reticulum? Write the functions of each.
Answer:
There are two types of endoplasmic reticulum – Rough endoplasmic reticulum and smooth endoplasmic reticulum. The functions of these are:

Rough endoplasmic reticulum – It looks rough as it has particles called ribosomes attached to its surface. Ribosomes are the site of protein synthesis.

Smooth endoplasmic reticulum:

• It helps in the manufacture of fat molecules, or lipids, important for cell function.
• Some proteins and lipids made by SER help in building the cell membrane and this process is known as membrane biogenesis.
• Helps in detoxifying many poisons and drugs in the liver cells of the group of vertebrates.

Question 11.
Draw a neat and labelled diagram of a typical prokaryotic cell.
Answer:

Question 12.
Why do plant cells possess large sized vacuole?
Answer:
Plant cells possess large sized vacuoles as the vacuoles help to store many important substances. They contain cell sap that gives turgidity and rigidity to the plant cell.

Question 13.
Describe the structural features of cell membrane and cell wall. Why is cell membrane called selectively permeable membrane?
Answer:
Cell wall:

• It is a rigid outer covering which lies outside the plasma membrane.
• It is made of cellulose which provides structural strength to plants.
• The shrinkage or contraction of the contents of the cell away from the cell wall when a living plant cell loses water through osmosis is known as plasmolysis.

Cell membrane:

• It is the outermost covering of the cell.
• It separates the contents of the cell from its external environment.
• It is mainly composed of lipids and proteins.

The cell membrane is called selectively permeable as it permits the entry and exit of only some materials in and out of the cell. It prevents the movement of the contents of the cell out of the cell.

Question 14.
Explain in detail what do you know about the structure of the nucleus.
Answer:
The nucleus was discovered by Robert Brown in 1831. The structure and the features of nucleus are:

• It is a dark coloured, spherical or oval, dot-like structure near the centre of each cell.
• It is the control centre of the cell as it controls all the activities of the cell.
• It has a double layered covering called nuclear membrane.
• The nuclear membrane has pores which allow the transfer of materials from inside the nucleus to the cytoplasm.
• The nucleus plays a central role in cellular reproduction (process by which a single cell divides and forms two new cells).
• Nucleus along with the environment directs the chemical activities of the cell to determine the way the cell will develop and the form it will exhibit at maturity.
• Nuclear region of the cell may be poorly defined due to the absence of a nuclear membrane in some organisms like bacteria. Such an undefined nuclear region containing only nucleic acids is called a nucleoid.

Question 15.
Differentiate between rough and smooth endoplasmic reticulum. How is endoplasmic reticulum important for membrane biogenesis?
Answer:
The differences between smooth endoplasmic reticulum and the rough endoplasmic reticulum are:

Smooth Endoplasmic Reticulum (SER):

• SER looks smooth as it does not have ribosomal particles on the surface.
• SER helps in the manufacture of lipids and fat molecules and also in detoxifying many poisons and drugs in the liver cells of the group of vertebrates.

Rough Endoplasmic Reticulum (RER):

• RER appears rough as it has particles of ribosomes on the surface.
• Ribosomes present on RER are the sites of protein synthesis.

Ribosomes are the sites of protein synthesis in all active cells. Endoplasmic reticulum helps in transporting these proteins to various places. Some proteins and lipids made by SER help in building the cell membrane, this process is known as membrane biogenesis.

Question 16.
Describe the phenomenon of membrane biogenesis. Give one function of ER.
Answer:
Some proteins and lipids made by SER help in building the cell membrane and this process is known as membrane biogenesis.

ER serves as channels for the transport of materials (especially proteins) between various regions of the cytoplasm or between the cytoplasm and the nucleus. It also functions as a cytoplasmic framework providing a surface for some of the biochemical activities of the cell.

Question 17.
(i) Why are lysosomes known as ‘scavengers of the cell’?
(ii) Lysosomes are self-destructive. (True/False). Give reason.
Answer:
(i) The lysosomes are waste disposal system of the cell as they remove the debris and help to keep the cell clean by digesting any foreign material as well as worn-out cell organelles. Thus, they are known as the ‘scavengers of the cell’.

(ii) It is true that the lysosomes are self-destructive. They contain digestive enzymes. If the cell gets damaged during disturbance in cellular metabolism, the lysosomes may burst and its enzymes digest their own cell.

Question 18.
Name the organelle of the cell, which has membrane bound sac filled with powerful digestive enzymes. Write any four common functions it performs inside the cell.
Answer:
Lysosome is a membrane bound sac filled with powerful digestive enzymes.

The functions of lysosomes are:

• They are waste disposal system of the cell as they help to keep the cell clean by digesting any foreign material as well as worn-out cell organelles.
• They have digestive enzymes which are capable of breaking down all organic materials.
• If any disturbance occurs in the cellular metabolism or the cell gets damaged, the lysosomes burst open and its digestive enzymes digest all the contents of the cell. So, they are also called as the ‘suicide bags’ of the cell.
• During starvation they digest the food contents of the cell and provide energy to the cell.

Question 19.
State reasons for the following:
(i) Mitochondria are known as the powerhouse of the cell.
(ii) Plastids are able to make their own protein.
(iii) Plant cell shrinks when kept in hypertonic solution.
Answer:
(i) Mitochondria are known as the powerhouse of the cell as they are the site of storage of ATP which helps to provide energy for all the activities of the cell.

(ii) Plastids are able to make their own protein as they have their own DNA and ribosomes.

(iii) Hypertonic solution has a lower concentration of water than the cell. Due to this, the water moves out of the plant cell by exosmosis and results in shrinkage of the plant cell.

Question 20.
List the specific functions of the following:
(i) Endoplasmic reticulum
(ii) Golgi apparatus
(iii) Lysosomes
(iv) Plastids
(v) Mitochondria
(vi) Vacuoles.
Answer:
The specific functions are:
(i) Endoplasmic reticulum: Site of protein synthesis.

(ii) Golgi apparatus: Storage, modification and packaging of products in vesicles.

(iii) Lysosomes: Waste disposal system of the cell as they help to keep the cell clean by digesting any foreign material as well as worn-out cell organelles.

(iv) Plastids: Green coloured plastids are the site of photosynthesis.

(v) Mitochondria: They are called the powerhouse of the cell as they store energy required for the activities of the cell in the form of ATP.

(vi) Vacuoles: Provide turgidity and rigidity to the cell in plant cells. They also help in digestion of food and expulsion of excess water and waste from the cell in unicellular organisms like Amoeba.

Question 21.
Which types of plastids stores starch, oil and proteins?
Answer:
The leucoplasts help to store starch, oil and proteins in the amyloplasts, elaioplasts and aleuroplasts respectively.

Question 22.
How many membranes are present in mitochondria? Give the characteristic features of these membranes. What is the advantage of such features?
Answer:
Mitochondrion is a double-membrane structure whose outer membrane is very porous while the inner membrane is deeply folded to form cristae. The porous membrane helps in getting oxygen and food. Cristae present on the inner membrane are the folds which create a large surface area for ATP- generating chemical reactions.

Question 23.
Why are lysosomes known as ‘suicide-bags’ of a cell?
Answer:
Lysosomes are also known as the ‘suicide bags’ of a cell because if the cell gets damaged during disturbance in cellular metabolism, the lysosomes may burst and its enzymes digest their own cell.

Question 24.
Do you agree that “A cell is a building unit of an organism”. If yes, explain why?
Answer:
Yes, a cell is the building unit or the fundamental unit of an organism as the cells get organised to form tissues which in turn get organised into organs and further into organ system which organise to form an organism. It can be represented as:
Cell → tissue → organ → organ system organism

Question 25.
Why does the skin of your finger shrink when you wash clothes for a long time?
Answer:
The skin of our finger shrinks when we wash clothes for a long time because soap solution is a hypertonic solution i.e., very concentrated solution, so water moves out of our finger cells by the process of osmosis (called as exosmosis).

Question 26.
Why is endocytosis found in animals only?
Answer:
The plant cells have a rigid structure due to the presence of cell wall around their cell membrane whereas in the animals the cell membrane does not have a cell wall. So, endocytosis can occur only in the animal cells.

Question 27
A person takes concentrated solution of salt, after sometime, he starts vomiting. What is the phenomenon responsible for such situation? Explain.
Answer:
A concentrated solution of salt is hypertonic solution and causes dehydration. Water moves out of the cells and exosmosis in the parts of stomach and intestine make the person feel uncomfortable. Excessive dehydration results in anti-peristalsis due to which person starts vomiting.

Question 28.
Name any cell organelle which is non membranous.
Answer:
Ribosomes are non membranous organelles.

Question 29.
We eat food composed of all the nutrients like carbohydrates, proteins, fats, vitamins, minerals and water. After digestion, these are absorbed in the form of glucose, amino acids, fatty acids, glycerol, etc. What mechanisms are involved in absorption of digested food and water?
Answer:
Absorption of the nutrients takes place by diffusion and that of water occurs by the process of osmosis.

Question 30.
If you are provided with some vegetables to cook. You generally add salt into the vegetables during cooking process. After adding salt, vegetables release water. What mechanism is responsible for this?
Answer:
Adding salt into vegetables creates a hypertonic medium around them which results in exosmosis. Exosmosis causes release of water form vegetables.

Question 31.
If cells of onion peel and RBC are separately kept in hypotonic solution, what among the following will take place? Explain the reason for your answer.
(a) Both the cells will swell.
(b) RBC will burst easily while cells of onion peel will resist the bursting to some extent.
(c) a and b both are correct.
(d) RBC and onion peel cells will behave similarly.
Answer:
(b) RBC will burst easily while cells of onion peel will resist the bursting to some extent. This happens because the cells of onion peel have cell wall which prevents them from bursting. The RBC, being animal cells are devoid of cell wall and burst easily in hypotonic solution.

Question 32.
Bacteria do not have chloroplast but some bacteria are photo-autotrophic in nature and perform photosynthesis. Which part of bacterial cell performs this?
Answer:
The photo-autotrophic bacteria have small vesicles associated with plasma membrane which help in the process of photosynthesis.

Question 33.
Match the following A and B

Answer:
(a) (iv)
(b) (v)
(c) (iii)
(d) (i)
(e) (ii)

Question 34.
Write the name of different plant parts in which chromoplast, chloroplast and leucoplast are present. Chromoplasts are present in the flower and fruit.
Answer:
Chloroplasts are present in the leaves of the plant. Leucoplasts are present in the root of the plant.

Question 35.
Name the organelles which show the analogy written as under
(a) Transporting channels of the cell _______
(b) Powerhouse of the cell _______
(c) Packaging and dispatching unit of the cell _______
(d) Digestive bag of the cell _______
(e) Storage sacs of the cell _______
(f) Kitchen of the cell _______
(g) Control room of the cell _______
Answer:
(a) Transporting channels of the cell _______ Endoplasmic reticulum
(b) Powerhouse of the cell _______ Mitochondria
(c) Packaging and dispatching unit of the cell _______ Golgi body
(d) Digestive bag of the cell _______ Lysosome
(e) Storage sacs of the cell _______ Vacuole
(f) Kitchen of the cell _______ Chloroplast
(g) Control room of the cell _______ Nucleus

Question 36.
How is a bacterial cell different from an onion peel cell?
Answer:
Bacterial cell is a prokaryote so, they are smaller in size, their nucleus does not have a well defined nuclear membrane, possess a single chromosome and the cell is devoid of any cell organelles. Onion peel cell is an eukaryotic cell which is comparatively bigger in size, nucleus has a well defined nuclear membrane, possess more than one chromosome and have well defined cell organelles.

Question 37.
How do substances like carbon dioxide (CO₂) and water (H₂O) move in and out of the cell?
Answer:
The movement of carbon dioxide occurs by the process of diffusion in and out of the cell whereas the movement of water in and out of the cell occurs by the process of osmosis.

Question 38.
How does Amoeba obtain its food?
Answer:
Amoeba takes in food with the help of finger like extensions called pseudopodia by the process called endocytosis. Pseudopodia help to engulf the food which gets enclosed in a food vacuole. The complex particles of the food get broken down into simpler substances inside the food vacuole and diffuse into the cytoplasm of Amoeba. The undigested food particles are removed from the cell by exocytosis.

Question 39.
Name the two organelles in a plant cell that contain their own genetic material and ribosomes.
Answer:
Mitochondria and plastids (e.g. chloroplasts) contain their own genetic material and ribosomes.

Question 40.
Why are lysosomes also known as “scavengers of the cells”?
Answer:
The lysosomes are waste disposal system of the cell as they remove the debris and help to keep the cell clean by digesting any foreign material as well as worn-out cell organelles.

Question 41.
Which cell organelle controls most of the activities of the cell?
Answer:
Nucleus is the control centre of the cell and controls most of the activities of the cell.

Question 42.
Which kind of plastid is more common in
(a) roots of the plant
(b) leaves of the plant
(c) flowers and fruits
Answer:
The plastid that is more common in
(a) roots of the plant is leucoplast.
(b) leaves of the plant is chloroplast.
(c) flowers and fruits is chromoplast.

Question 43.
Why do plant cells possess large sized vacuole?
Answer:
The plant cells possess large sized vacuoles as the vacuoles help to store many important substances. They contain cell sap that gives turgidity and rigidity to the plant cell.

Question 44.
How are chromatin, chromatid and chromosomes related to each other?
Answer:
The chromatin material forms chromatids, i.e., chromatids are made up of chromatin. The chromosomes are made up of thread like structures called as chromatids.

Question 45.
What are the consequences of the following conditions?
(a) A cell containing higher water concentration than the surrounding medium
(b) A cell having low water concentration than the surrounding medium.
(c) A cell having equal water concentration to its surrounding medium.
Answer:
The consequences of the following conditions are:
(a) A cell containing higher water concentration than the surrounding medium will undergo exosmosis.

(b) A cell having low water concentration than the surrounding medium will undergo endosmosis.

(c) A cell having equal water concentration to its surrounding medium will not be affected as there won’t be any net movement of water into or outside the cell.

The Fundamental Unit of Life Class 9 Extra Questions Long Answer Type

Question 1.
Distinguish between hypotonic solution, isotonic solution and hypertonic solution.
Answer:
The differences between the three kinds of solutions are:

Question 2.
Describe the roles played by lysosomes. Why are they termed as suicidal bags? How do they perform their function?
Answer:
Roles played by lysosomes are:
(i) They are waste disposal system of the cell as they help to keep the cell clean by digesting any foreign material as well as worn-out cell organelles.

(ii) Lysosomes have powerful digestive enzymes capable of breaking down all organic materials. Lysosomes are also known as the ‘suicide bags’ of a cell because if the cell gets damaged during disturbance in cellular metabolism, the lysosomes may burst and its enzymes digest their own cell. They perform this function as they are membrane-bound sacs filled with hydrolytic and digestive enzymes made by rough endoplasmic reticulum (RER).

Question 3.
(a) Name the organelle which provides turgidity and rigidity to the plant cell. Name any two substances which are present in it.
(b) How are they useful in unicellular organisms?
Answer:
(a) The organelle which provides turgidity and rigidity to the plant cell is the large central vacuole which is filled with cell sap. The substances present in it are amino acids, sugars, various organic acids and some proteins.

(b ) They are very useful for the unicellular organisms in the form of food vacuole and contractile vacuole which perform the following functions:

Food vacuole found in Amoeba contains the food items that the Amoeba has consumed.
Contractile vacuole found in some unicellular organisms help in expelling excess water and some wastes from the cell.

Question 4.
What will happen if:
(i) Ribosomes are removed from the cell?
(ii) Golgi apparatus is removed from the cell?
(iii) Plasma membrane ruptures?
Answer:
(i) If ribosomes are removed from the cell, protein synthesis will not take place, enzymes will not be formed and ultimately death of cell will occur.

(ii) If golgi apparatus is removed from the cell, storage, modification and the packaging of substances in vesicles will not occur and lysosomes will not be formed.

(iii) Plasma membrane is a selectively permeable membrane, so in its absence, the entry and exit of the substances will not be regulated, contents of the cell will leak out and the cell will die.

Question 5.
Draw a plant cell and label the parts which
(a) determines the function and development of the cell
(b) package materials coming, from the endoplasmic reticulum
(c) provides resistance to microbes to withstand hypotonic external media without bursting
(d) is site for many biochemical reactions necessary to sustain life
(e) is a fluid contained inside the nucleus
Answer:
(a) Nucleus
(b) Golgi apparatus
(c) Cell wall
(d) Cytoplasm
(e) Nucleoplasm

Question 6.
Illustrate only a plant cell as seen under electron microscope. How is it different from an animal cell?
Answer:

Plant Cell:

• Cell wall is present.
• Plastids are present.
• A large central vacuole is present.
• Centrioles are absent.

Animal Cell:

• Cell wall is absent.
• Plastids are absent.
• Vacuoles are either absent or very small.
• Centrioles are present.

Question 7.
Draw a neat labelled diagram of an animal cell.
Answer:

Question 8.
Draw a well labelled diagram of an eukaryotic nucleus. How is it different from a nucleoid?
Answer:

It is different from a nucleoid as it is a membrane bound organelle.

Question 9.
Differentiate between rough and smooth endoplasmic reticulum. How is endoplasmic reticulum important for membrane biogenesis?
Answer:
Smooth Endoplasmic Reticulum (SER):

• SER looks smooth as it does not have ribosomal particles on its surface.
• SER helps in the manufacture of lipids and fat molecules and also in detoxifying many poisons and drugs in the liver cells of the group of vertebrates.

Rough Endoplasmic Reticulum (RER):

• RER appears rough as it has particles of ribosome on its surface.
• Ribosomes present on RER are the sites of protein synthesis.

Ribosomes are the sites of protein synthesis in all active cells. Endoplasmic reticulum helps in transporting these proteins to various places. Some proteins and lipids made by SER help in building the cell membrane, this process is known as membrane biogenesis.

Question 10.
In brief state what happens when
(a) dry apricots are left for sometime in pure water and later transferred to sugar solution?
(b) a red blood cell is kept in concentrated saline solution?
(c) the plasma-membrane of a cell breaks down?
(d) Rhoeo leaves are boiled in water first and then a drop of sugar syrup is put on it?
(e) golgi apparatus is removed from the cell?
Answer:
(a) If dry apricots are left for sometime in pure water they swell up due to endosmosis and later when they are transferred to sugar solution exosmosis occurs and they shrink.

(b) If a red blood cell is kept in concentrated saline solution it will lose water and shrink.

(c) If the plasma-membrane of a cell breaks down, the cell will die.

(d) If Rhoeo leaves are boiled in water first and then a drop of sugar syrup is put on it, no plasmolysis occurs as the cells get killed on boiling.

(e) If the golgi apparatus is removed from the cell, all sorts of vesicle formation in the cell get stopped.

Question 11.
Draw a neat diagram of plant cell and label any three parts which differentiate it from animal cell.
Answer:
The plant cells have chloroplast, large central vacuole and the cell wall which are not present in animal cells.

The Fundamental Unit of Life Class 9 Extra Questions HOTS

Question 1.
Unicellular organisms like Amoeba and Paramoecium survive as a single cell. How?
Answer:
In Amoeba and Paramoecium all the activities like digestion, absorption, assimilation, etc., which are necessary for life are carried out by a single cell. This enables them to survive even as a single cell.

Question 2.
Explain how cell walls permit the cells of fungi to withstand very dilute external media without bursting.
Answer:
The fungal cells swell up in very dilute external media as they take in water by the process of endosmosis. The plasma membrane of the cell exerts pressure on the cell wall and the cell wall also exerts an equal pressure on the membrane which helps to prevent the cell from bursting.

Question 3.
Give the roles of the following:
(i) Lipids and proteins of plasma membrane
(ii) Cellulose in the cell wall
(iii) Flexible nature of the cell membrane
(iv) Hydrolytic enzymes of lysosomes
(v) Ribosomes present on the RER
Answer:
The roles are:
(i) Lipids and proteins of plasma membrane: Provide flexibility to cell membrane and make it selectively permeable in nature.

(ii) Cellulose in the cell wall: Provides structural strength to the plants and prevents bursting of the cell when the cell swells in a hypotonic solution.

(iii) Flexible nature of the cell membrane: It helps organisms like Amoeba to engulf food by endocytosis.

(iv) Hydrolytic enzymes of lysosomes: Helps in the process of cell digestion and act as ‘scavengers of cell’.

(v) Ribosomes present on the RER: Are the site of protein synthesis.

Question 4.
Which cell organelle will play a major role when a cell is damaged due to disturbance in cellular metabolism? How?
Answer:
Lysosomes will play a major role when a cell is damaged due to disturbance in cellular metabolism. The lysosomes burst open and its hydrolytic digestive enzymes digest their own cell contents. Thus, lysosomes are also called as the ‘suicidal bags’.

Question 5.
What will be the effect on the cell when:
(a) The cell is placed in a medium having lower water concentration.
(b) The cell is placed in a medium having higher water concentration.
(c) The cell is placed in a medium having water concentration which is equal to that inside the cell.
Answer:
The consequences of the following conditions are:
(a) The cell having low water concentration than the surrounding medium will undergo endosmosis.
(b) The cell containing higher water concentration than the surrounding medium will undergo exosmosis.
(c) The cell having equal water concentration to its surrounding medium will not be affected as there won’t be any net movement of water into or outside the cell.

The Fundamental Unit of Life Class 9 Extra Questions Value Based (VBQs)

Question 1.
Rajni was told by his teacher that cell is the structural and fundamental unit of life. She asked her teacher to give reasons to support her statement. She felt very happy when her teacher showed her the slide of onion peel with the help of a microscope. She was able to identify the various parts of the cells visible in the slide.
(i) Why is the cell called the structural and functional unit of life?
(ii) With the help of a suitable diagram show the cells observed in onion peel and label them.
(iii) What values are shown by Rajni?
Answer:
(i) The body of all living organisms is composed of one or more cells, so cell is called the structural unit of life. Also, the various life processes like digestion, respiration, excretion, etc., are performed by the cells, so the cell is called the functional unit of life.

(ii) The cells of onion peel are shown in the diagram below.

(iii) Values shown by Rajni are curiosity, scientific temper, knowledge and sincerity towards her work.

 

In this page, we are providing Why Do we Fall Ill Class 9 Extra Questions and Answers Science Chapter 13 pdf download. NCERT Extra Questions for Class 9 Science Chapter 13 Why Do we Fall Ill with Answers will help to score more marks in your CBSE Board Exams. https://ncertmcq.com/extra-questions-for-class-9-science/

Class 9 Science Chapter 13 Extra Questions and Answers Why Do we Fall Ill

Extra Questions for Class 9 Science Chapter 13 Why Do we Fall Ill with Answers Solutions

Why Do we Fall Ill Class 9 Extra Questions Very Short Answer Type

Why Do We Fall Ill Class 9 Extra Questions Question 1.
What are infectious or communicable diseases?
Answer:
The diseases which are caused by infectious agents are called as infectious diseases as they can spread from one person to another through some medium or by direct contact.
Example: Pneumonia, common cold, tuberculosis, etc.

Why Do We Fall Ill Extra Questions Question 2.
What are congenital diseases?
Answer:
The diseases which are present in a person since birth are called congenital diseases.
Example: colour blindness.

Why Do We Fall Ill Class 9 Extra Questions Pdf Question 3.
Give one local and one general effect of the inflammation process.
Answer:
Swelling or pain is a local effect. Fever or headache is a general effect.

Class 9 Why Do We Fall Ill Extra Questions Question 4.
Name the organism causing the following diseases:
(a) Kala-azar
(b) Sleeping sickness
Answer:
Kala-azar is caused by Leishmania; Sleeping sickness is caused by Trypanosoma.

Class 9 Science Chapter 13 Extra Questions And Answers Question 5.
It was diagnosed that a patient has lost the power of fighting any infection.
(i) Name the disease the patient is suffering from.
(ii) Name the pathogen responsible for the disease.
Answer:
(i) AIDS.
(iii) HIV is the causative organism of AIDS. [HIV-Human immunodeficiency virus]

Extra Questions Of Why Do We Fall Ill Question 6.
What is immunity?
Answer:
The ability of the body of a person to fight against the disease causing organisms is called immunity. Name any disease that can be prevented by using vaccines.

Class 9 Science Ch 13 Extra Questions Question 7.
The diseases which can be prevented by using vaccines.
Answer:
The diseases which can be prevented by using vaccines are polio, small pox, diphtheria, tetanus, measles, etc.

Extra Questions Of Why Do We Fall Ill Class 9 Question 8.
What are principles of treatment of a disease?
Answer:
The principles of treatment are:

• reducing the effects of the disease.
• to kill the cause of the disease.

Extra Questions On Why Do We Fall Ill Question 9.
How do children in many parts of India get immune to hepatitis-A by the time they are five year old?
Answer:
The children become immune to hepatitis A virus as they are exposed to hepatitis A virus present in the water they drink.

Ch 13 Science Class 9 Extra Questions Question 10.
Name the causative organisms of tuberculosis and cholera.
Answer:
Tuberculosis: Caused by bacterium called as Mycobacterium tuberculosis.
Cholera is caused by a bacterium called as Vibrio cholera

Why Do we Fall Ill Class 9 Extra Questions Short Answer Type 1

Extra Questions Why Do We Fall Ill Question 1.
What are the differences between acute and chronic diseases?
Answer:
Acute disease:

• The disease which lasts for only very short periods of time is called acute disease.
• They get over soon and do not get much time to affect the health more adversely. Example: Common cold

Chronic disease:

• The disease which can last for a long time, even as much as a lifetime is called chronic disease.
• They have a long-term effect on the health of a person. Example: Elephantiasis

Class 9 Science Why Do We Fall Ill Extra Questions Question 2.
What is a pandemic disease? Give one example.
Answer:
The disease which affects the health of human population all over the world is called a pandemic disease. For example, AIDS.

Class 9 Biology Chapter 13 Extra Questions Question 3.
Mention the symptoms because of which you will visit a doctor and why?
Answer:
High fever, headache, tiredness, loose motion, cough and cold, loss of appetite and body weight are some of the symptoms for which we will visit a doctor because the doctor would be able to ascertain the disease caused on the basis of the symptoms produced and give medication accordingly.

Class 9 Biology Why Do We Fall Ill Extra Questions Question 4.
Why is DPT called triple antigen?
Answer:
DPT is called as triple antigen as it affects three antigens to produce the antibodies against them. The diseases are: Diphtheria, Pertussis and Tetanus.

Extra Questions From Why Do We Fall Ill Question 5.
What are the symptoms shown by a person if the
(i) lungs get infected?
(ii) stomach is infected?
Answer:
(i) Cough, breathlessness, tiredness are the symptoms produced if the lungs of a person get affected by a disease.

(ii) Loose motion, vomiting and stomachache are the symptoms produced when the stomach of a person gets affected by a disease.

Question 6.
“In our country majority of children are already immune to hepatitis A without giving its vaccine to them.” Justify this statement giving reasons.
Answer:
Majority of the children are already exposed to the hepatitis A virus by the time they are five years old because the water which the children generally drink contains the hepatitis A virus. The immune system thus helps to develop immunity against the virus.

Question 7.
List any four factors that must be taken care of by an individual for keeping good health.
Answer:
The four factors which must be taken care by an individual for keeping good health are:

• Proper nourishing balanced diet
• Clean and hygienic environment
• Good social environment
• Proper sanitation and cleanliness

Question 8.
Why are antibiotics effective against bacteria?
Answer:
Antibiotics block the biochemical pathways of the bacteria which inhibit their growth and kill them. For example: Penicillin blocks the pathway involved in the synthesis of cell wall which protects the bacteria. This inhibits their growth and kills them.

Question 9.
Influenza or common cold spreads faster and is difficult to control. Explain.
Answer:
Influenza and common cold are infectious diseases which are spread through air, so it becomes difficult to control them.

Question 10.
Why are overcrowded and poorly ventilated areas, major factors in the spread of air-borne diseases?
Answer:
In poorly ventilated and overcrowded areas, the little droplets containing air-borne microbes thrown by an infected person on coughing or sneezing, can be easily inhaled by a healthy person standing close by. This can start a new infection in the healthy person. Hence, such areas are major factors in the spread of air-borne diseases.

Question 11.
(a) Name the organ into which the malarial parasite enters after a mosquito bite.
(b) Give two examples of air-borne diseases.
Answer:
(a) The malarial parasite enters the liver of the healthy person after mosquito bite.
(b) Common cold and pneumonia are some air-borne diseases.

Question 12.
What are non-infectious diseases? Give two examples of non-infectious diseases.
Answer:
The diseases which do not spread from one person to the other person in the community are called as non-infectious diseases. They are caused due to internal factors.
Example: Cancer, high blood pressure, diabetes, etc.

Question 13.
Identify infectious and non-infectious diseases from the diseases given below: Tuberculosis, goitre, marasmus and typhoid.
Answer:

• Infectious diseases are tuberculosis and typhoid.
• Non-infectious diseases are goitre and marasmus.

Question 14.
Write the symptoms and diseases associated with the following:
(a) when microbes attack the lungs
(b) when the virus enters the liver
Answer:
(a) Tuberculosis may occur when microbes attack the lungs. The symptoms would be persistent cough, blood in sputum, prolonged low fever.

(b) Jaundice may occur when the virus enters the liver. The symptoms would be headache, high fever, loss of appetite and dark yellow coloured urine.

Question 15.
Why does a person suffering from the disease HIV-AIDS dies even due to small infection?
Answer:
The HIV damages the immune system of the person suffering from AIDS. Due to this the body of the person is unable to fight against even the small infections. The immune system of the person becomes very weak and ultimately leads to the death of the person due to several infections.

Why Do we Fall Ill Class 9 Extra Questions Short Answer Type 2

Question 1.
(a) Define disease.
(b) Explain briefly the two groups of diseases.
Or
Differentiate between infectious and non-infectious diseases.
Answer:
(a) Disease refers to any condition that disturbs the normal functioning of the living organism. It is a condition of disturbed ease when an individual feels uncomfortable.

(b) The two groups of diseases are infectious diseases and the non-infectious diseases.
Infectious diseases:

• These diseases are caused by infectious agents. These can spread from one person to another through some medium or by direct contact.
• Example: Pneumonia, common cold, tuberculosis, etc.

Non-infectious diseases:

• These do not spread form one person to the other person in the community. They are caused due to
• internal factors.
  Example: Cancer, high blood pressure, diabetes, etc.

Question 2.
What are acute and chronic diseases? Which one of the two is more harmful and why? Give an example in support of your answer.
Answer:
Acute disease:

• The disease which lasts for only very short periods of time is called acute disease.
• They get over soon and do not get much time to affect the health more adversely. Example: Common cold

Chronic disease:

• The disease which can last for a long time, even as much as a lifetime is called chronic disease.
• They have a long-term effect on the health of a person. Example: Elephantiasis

Chronic diseases are more harmful as they persist for a long time and thus adversely affect the general health of the person suffering from them.

Question 3.
Giving reasons, justify that it is difficult to prepare antiviral medicines than antibiotics.
Or
Why is it difficult to prepare anti-viral medicines than antibiotics?
Or
Explain why antibiotics do not work against viruses but work against many group of bacteria.
Answer:
Antibiotics are the chemicals which usually block the biochemical pathways of the bacteria. This inhibits their growth and kills them. But, the viruses do not have their own biochemical pathways as present in the bacteria. Viruses use the host machinery to multiply themselves. So, it becomes difficult to prepare anti-viral vaccines in order to inhibit their growth.

Question 4.
How do diseases spread through air? Name two such diseases.
Answer:
The diseases spread through air when little droplets thrown out by an infected person who sneezes or coughs are inhaled by a healthy person. This results in a new infection in the healthy person.
Example: Common cold, pneumonia and tuberculosis.

Question 5.
Why does a person who has suffered once from small pox cannot suffer with it again?
Answer:
The immune system of our body responds against the disease causing small pox virus when it encounters it for the first time. This interaction is slower and less vigorous, but the immune system remembers the virus specifically. Whenever the immune system encounters the virus after this first response, the interaction is more vigorous and the immune system completely eliminates the virus. Thus, the small pox virus is not able to affect the person who has suffered from it once.

Question 6.
How is the principle of immunisation implemented for eliminating polio?
Answer:
The polio vaccine which is administered to the children in the form of polio drops contains the weakened polio causing pathogen which is not able to cause the disease but enables the immune system of the child to produce antibodies against the polio virus. Subsequent encounter of the child to the polio virus activates the immune system which kills the polio virus and protects the immunised child from the disease. Thus, principle of immunisation helps in eliminating polio.

Question 7.
Give the cause and the remedy of:
(a) Hepatitis
(b) AIDS
(c) Malaria
Answer:

Question 8.
“Being disease free is not the same as being healthy.” Explain the statement by giving an example.
Answer:
Disease refers to any condition that disturbs the normal functioning of the living organism. It is a condition of disturbed ease when an individual feels uncomfortable. Being disease-free is a concept which applies to individual sufferer.

Even a disease free person can be considered as having a poor health if the person is unfit in terms of social and mental health. So, health is a concept which applies to societies and communities.

For example: a disease free person suffering from mental stress and tension cannot be considered as healthy.

Question 9.
A person was bitten by a stray dog. After some days his nature gets irritated, he started fearing water.
(a) Name the disease.
(b) Is there any vaccine available?
(c) Is there any plan of your local authority for the control of this disease?
Answer:
(a) The disease caused due to bite of a stray dog is rabies.
(b) Yes, anti-rabies vaccine is available.
(c) Local authorities have planned immunisation of the stray dogs against the disease.

Question 10.
It was diagnosed that the body of a patient had lost his power of fighting any infection. Name the disease the patient was suffering from. Which microbe is responsible for this disease? Give two ways by which it spreads from one person to another.
Answer:
The disease is called AIDS (Acquired immunodeficiency syndrome) and the microbe which is responsible for the disease is a virus called HIV (Human immunodeficiency virus). The ways to control the disease are:

• Creating awareness among people regarding the modes of spread of the disease.
• Use of disposable syringes in hospitals and clinics.
• Avoiding sexual contact with multiple partners.

Question 11.
Give two examples for each of the following:
(a) Acute diseases
(b) Chronic diseases
(c) Infectious diseases
(d) Non-infectious diseases
Answer:
(a) Acute diseases: Common cold, eye flu
(b) Chronic diseases: Tuberculosis (TB), asthma
(c) Infectious diseases: Chicken pox, small pox
(d) Non-infectious diseases: Goitre, Cancer

Question 12.
Name two diseases caused by Protozoans. What are their causal organisms.
Answer:
Malaria is caused by Plasmodium and Kala-azar caused by Leishmania Symptoms of malaria are: high fever and shaking chills that can range from moderate to severe, profuse sweating, headache, nausea, vomiting, etc. Symptoms of Kala-azar are breathing difficulty, recurrent fever and skin sores.

Question 13.
Which bacterium causes peptic ulcers? Who discovered the above pathogen for the first time?
Answer:
Heliobacterium pylori cause peptic ulcers. This pathogen was discovered for the first time by Marshall and Warren.

Question 14.
What is an antibiotic? Give two examples.
Answer:
The chemicals secreted by some microorganisms which can kill the bacteria and other disease causing pathogens are called antibiotic. Example: Penicillin, Streptomycin

Question 15.
Fill in the blanks
(a) Pneumonia is an example of ________ disease.
(b) Many skin diseases are caused by ________
(c) Antibiotics commonly block biochemical pathways important for the growth of ________
(d) Living organisms carrying the infecting agents from one person to another are called ________
Answer:
(a) Communicable
(b) Fungi
(c) Bacteria
(d) Vector

Question 16.
Name the target organs for the following diseases
(a) Hepatitis targets ________
(b) Fits or unconsciousness targets ________
(c) Pneumonia targets ________
(d) Fungal disease targets ________
Answer:
(a) Liver
(b) Brain
(c) Lungs
(d) Skin

Question 17.
Who discovered Vaccine’ for the first time? Name two diseases which can be prevented by using vaccines.
Answer:
Edward Jenner discovered vaccine for the first time. Polio, small pox, typhoid, etc. can be prevented by vaccines.

Question 18.
Fill in the blanks:
(a) ________ disease continues for many days and causes effect the on body.
(b) ________ disease continues for a few days and causes short term effect on the body.
(c) ________ is defined as physical, mental and social well-being and comfort.
(d) Common cold is an ________ disease.
(e) Many skin diseases are caused by ________
Answer:
(a) Chronic, long-term
(b) Acute
(c) Health
(d) Infectious
(e) Fungi

Question 19.
Classify the following diseases as infectious or non-infectious.
(a) AIDS
(b) Tuberculosis
(c) Cholera
(d) High blood pressure
(e) Heart disease
(f) Pneumonia
(g) Cancer
Answer:
(a) infectious
(b) infectious
(c) infectious
(d) non-infectious
(e) non-infectious
(f) infectious
(g) non-infectious

Question 20.
Name any two groups of microorganisms from which antibiotics can be extracted.
Answer:
Bacteria and fungi are the microorganisms from which antibiotics can be extracted.

Question 21.
Name any three diseases transmitted through vectors.
Answer:
Filariasis, Dengue, Chikungunya, Malaria, Kala-azar

Why Do we Fall Ill Class 9 Extra Questions Long Answer Type

Question 1.
(a) Give definition of health.
(b) State and explain in brief the four major factors which cause disease.
Answer:
(a) ‘Health’ is defined as a state of physical, emotional, mental and social well being of a person.
(b) The four factors whose non availability or absence can cause disease are:
(i) Proper nourishing food: If the person does not get proper nourishing food and a balanced diet, then disease may affect the person.

(ii) Proper hygienic conditions and cleanliness: If the surroundings are not hygienic and the public cleanliness is ignored in a society, then the individuals living there become more prone to diseases.

(iii) Good social conditions: The society in which the person lives should cater towards a healthy mind set of the members of the society. A bad social environment makes the individuals of the society develop an unhealthy attitude.

(iv) Good economic conditions: Poverty is a major cause of diseases and poor economic conditions increase the chances of spread of diseases in the society due to inadequate food and unhygienic conditions.

Question 2.
(a) Doctors diagnosed that Radha was suffering from HIV-AIDS. List any two methods by which she might have come in contact with the disease. Name the organ affected by this disease.
(b) Why antibiotics cannot be used for its treatment? Justify your answer.
Answer:
(a) AIDS can spread by four ways: Sexual contact, Transfusion of AIDS infected blood, use of infected syringe and from an infected mother to her baby during pregnancy or through breast feeding.

(b) Antibiotics block the biochemical pathways of the microorganism in order to inhibit their growth and kill them. But, the viruses do not employ such biochemical pathways of their own. They utilise the host machinery to multiply themselves. So, antibiotics cannot be used for the treatment of the viral diseases like AIDS.

Question 3.
(a) If a person is suffering from jaundice, name the mode of its transmission and the organ affected by the disease.
(b) List one general mode of prevention of jaundice.
(c) It has been observed that despite the availability of the vaccine of Hepatitis A in the market, it may not be necessary to be given to children by the time they are 5 years old. Why?
Answer:
(a) Mode of transmission of Jaundice: Contaminated water Organ affected by Jaundice: Liver

(b) Access to pure drinking water can prevent jaundice.

(c) Most of the children of India are already exposed to the hepatitis A virus through the drinking water and their immune system helps to develop immunity against the disease by the time they are five years old. So, it is not necessary to give them the hepatitis A vaccine.

Question 4.
Give an account of malaria, giving its causative agent, symptoms and control measures.
Answer:
Malaria is a protozoan disease caused by Plasmodium species. It gets transmitted by a vector called as the female Anopheles mosquito. The symptoms of malaria are high fever and body ache. The patient feels chills and shivering at regular time intervals. The disease can be controlled by eliminating the breeding grounds of mosquitoes, using mosquito nets or mosquito repellents at home, taking a dose of quinine medicine as prescribed by the doctor.

Question 5.
(a) Name two air-borne diseases. How does the disease causing microbes spread through air?
(b) How does HIV virus spread from a patient to a healthy person?
(c) How does the immune system of our body function?
Answer:
(a) Common cold, tuberculosis, pneumonia are some air-borne infections. They spread from one person to another when an infected person releases droplets into air while coughing or sneezing and these droplets get inhaled by a healthy person standing close by. The microbes start a new infection in the healthy person.

(b) HIV can spread by the following ways: Sexual contact, transfusion of AIDS infected blood, from an infected mother to her baby during pregnancy or through breast feeding, use of infected syringe.

(c) The immune system gets activated on encountering a disease causing microbe or on infection and recruits many cells to the affected tissue by a process called as inflammation. This results in pain, swelling, fever, etc., but ultimately it results in killing the disease causing microbe and prevent spread of infection.

Question 6.
(a) Discuss briefly the principle of immunisation.
(b) Mention any two diseases that can be prevented by immunisation.
Answer:
(a) The process by which immunity or resistance to a disease is developed in an individual by administration of biological preparations called vaccines is known as immunisation. In this process, a harmless or dead pathogen is introduced in the body of the organism by vaccination. The immune system of the organism gets activated and produces antibodies against the pathogen to kill it.

These antibodies remain in the memory of the immune system of the individual and in the case of any subsequent infection by the same microbe, these antibodies act quickly and more vigorously to kill the microbe. In this way, the microbe is not able to infect the person and the person gets immunised against the disease.

(b) Two diseases prevented by immunisation are: Measles and polio. Some other diseases which can be prevented by vaccination are diphtheria, pertusis, whooping cough, hepatitis, tetanus, etc.

Question 7.
Explain giving reasons
(а) Balanced diet is necessary for maintaining healthy body.
(b) Health of an organism depends upon the surrounding environmental conditions.
(c) Our surrounding area should be free of stagnant water.
(d) Social harmony and good economic conditions are necessary for good health.
Answer:
(a) Balanced diet provides raw materials and energy in appropriate amount needed for the proper growth and development of the body. It contains the nutrients like the protein, carbohydrates, fats, minerals etc., in the right amount which helps in the proper growth and functions. This ensures a good health of the individual.

(b) The physical, mental and the social well being of a person is affected by the surrounding environmental conditions. Since, these factors determine the health of a person, we can say that the health of a person depends on the environmental conditions. For example, Unhygienic surroundings as breeding grounds for disease causing organisms and their vectors can harm our health.

(c) Stagnant water is a source of many water-borne diseases and acts as breeding place for many insect vectors which can cause diseases in human beings. So, our surrounding area should be free of stagnant water.

(d) Social harmony ensures that the mental tensions and problems do not surround a person and friendly relations are maintained among the individuals of the society. They strive for the growth and well being of each other and thus better health is maintained in such environment and surroundings. Better economic conditions enable a person to invest more to attain good health by eating nutritive food, ensure protection from diseases, get better medical facilities, etc. So, health of a person is better maintained if economic conditions are good.

Question 8.
What is a disease? How many types of diseases have you studied? Give examples.
Answer:
Any condition that disturbs the normal functioning of the organism or its organs is called a disease. Diseases can be classified as acute, chronic, infectious, non-infectious, etc. The diseases which are for short duration are called acute whereas the diseases which persist for a long time are called chronic diseases, example common cold (acute) and tuberculosis (chronic).

The diseases which can be transmitted from one person to another are called infectious diseases whereas the ones which cannot be transmitted are called non-infectious diseases, example cancer and goitre respectively.

Question 9.
What do you mean by disease symptoms? Explain giving two examples.
Answer:
The physical disturbances or the visual changes which indicate the existence of a disease are called the symptoms of the disease.
Example:

• High fever and chills is a symptom of malaria.
• Appearance of lesions on the skin is a symptom of chickenpox.

Question 10.
Why is the immune system essential for our health?
Answer:
Immune system is essential as it helps our body to fight against disease causing microbes. It protects our body by secreting chemicals called antibodies or other substances which protect us from harmful microbes.

Question 11.
What precautions will you take to justify “prevention is better than cure”?
Answer:
The precautions which can be taken to protect ourselves from the disease are:

• Maintaining personal hygiene as well as clean surroundings.
• Being aware about diseases, their symptqms and the organism which causes then.
• Eating a balanced diet.
• Timely vaccination and regular medical, check-up.

Question 12.
Why do some children fall ill more frequently than others living in the same locality?
Answer:
The reasons due to which some children fall ill more frequently than others living in the same locality can be:

• Poor and inefficient immune system.
• Unhealthy food habits and not taking balanced diet.
• Not maintaining personal hygiene.

Question 13.
Why are antibiotics not effective for viral disease?
Answer:
The mode of action of the antibiotics is blocking the biosynthetic pathways of the bacteria and other microbes. However, viruses do not have such biochemical pathways or have very few biochemical mechanisms of their own, hence viruses are unaffected by antibiotics.

Question 14.
Becoming exposed to or infected with an infectious microbe does not necessarily mean developing noticeable disease. Explain.
Answer:
Becoming exposed to or infected with an infectious microbe does not necessarily mean developing noticeable disease because the immune system becomes active when it encounters a pathogen. If the immune system of the organism is able to ward off the disease causing microbe, then the disease will not occur and the person will remain disease-free. So, a strong immune system can ensure that we do not suffer from diseases even if we are exposed to infectious microbes.

Question 15.
Give any four factors necessary for a person to be healthy.
Answer:
The four factors necessary for a person to be healthy are:

• Proper nourishment and a balanced diet which help to provide a strong immune system.
• Maintaining personal hygiene to protect ourselves from infectious microbes.
• Timely vaccination against various diseases.
• Maintaining community hygiene and clean surroundings will to prevent the incidence of waterborne and the air-borne diseases.

Question 16.
Why is AIDS considered to be a ‘Syndrome’ and not a disease?
Answer:
The causative organism of AIDS is a virus called the HIV which gets transmitted through sexual contact, transfusion of contaminated blood, intravenous syringes used by drug addicts and from a mother suffering with AIDS to her child, spread to lymph nodes all over the body. The virus attacks the immune system of the organism and makes it so weak that it cannot fight against even the minor infections. Due to this even a small cold can develop into pneumonia or minor stomach infection may lead to severe diarrhoea and blood loss in stools.

Ultimately the immune system becomes very weak and leads to the death of the person suffering from AIDS. Many diseases simultaneously develop in such a person, so there is no specific disease symptom but a number of symptoms occur in the person. This group of symptoms are called as ‘syndrome’. So, AIDS is not a disease, it is a syndrome.

Why Do we Fall Ill Class 9 Extra Questions HOTS

Question 1.
The symptoms seen in a patient are high fever, constipation and stomach pain. A doctor wants to confirm whether the patient is suffering from Amoebiasis or typhoid. How can the doctor confirm it?
Answer:
The doctor can advise the patient to get a widal test done which helps to confirm the presence of typhoid causing microorganism in the body. If typhoid is ruled out then the patient is most likely to suffer from Amoebiasis.

Question 2.
Name the disease:
(a) that spreads by sexual contact but not by casual contact like handshake.
(b) that can be caused by virus, bacteria or protozoa.
(c) that can be caused due to bite of stray dog.
Answer:
(a) AIDS
(b) Diarrhoea
(c) Rabies

Question 3.
A mother who had suffered from chicken pox in her childhood, is now taking care of her child, who is suffering from the same disease. What are the chances of her mother having chicken pox? Explain.
Answer:
The mother will not suffer from chicken pox as she has become immune to chicken pox. During the first infection, her immune system develops antibodies against chicken pox. These antibodies respond with more vigour during the next infection, eliminate the microbe and thus prevent the person from the disease.

Question 4.
Name the disease:
(a) in which the liver of the person is the target.
(b) in which saliva of the infected animal spreads infection.
(c) against which BCG vaccine is given.
(d) for which widal test is done.
(e) in which sexual contact spreads the disease but not the physical contact in form of handshakes or hugging.
Answer:
(a) Jaundice and hepatitis
(b) Rabies
(c) Tuberculosis
(d) Typhoid
(e) AIDS

Question 5.
The immune system of a patient has been damaged by a virus. What is the probable disease which would have led to this effect on the immune system? What are the ways by which the pathogen would have been transferred into the individual?
Answer:
The disease is most likely to be AIDS caused by the HIV virus which damages the immune system of the person.

AIDS can be spread in four ways: Sexual contact, transfusion of AIDS infected blood, from an infected i mother to her baby during pregnancy or through breast feeding.

Question 6.
A patient bitten by a stray animal complained of excessive salivation, restlessness and a fear of water. What can be the probable disease and its cause? How can such disease be treated or controlled?
Answer:
The patient is probably suffering from rabies caused by the rabies virus. The disease can be controlled by ensuring proper vaccination of stray animals like dogs. The disease can be treated by timely administration of anti rabies vaccine.

Question 7.
A patient went to a doctor and complained of having a persistent cough, blood in sputum, breathlessness and loss of body weight. Name the disease and the causative microbe. How is the disease transmitted? Which vaccine is given to develop resistance against the disease?
Answer:
The disease from which the patient is suffering is Tuberculosis (T.B.) and the causative microbe is . a bacteria called Mycobacterium tuberculosis.. The disease gets transmitted when a healthy person inhales the droplets released by an infected person on coughing, sneezing or while talking. The vaccine i called BCG is given to develop resistance against the disease.

Question 8.
A child was suffering from loose motions, frequent vomiting, feeling of nausea and watery diarrhoea which led to an excessive loss of fluids from his body. Name the disease and its causative microbe. What measures, can be taken to treat this disease? How can one avoid getting infected by the disease?
Answer:
The person is infected with disease called cholera which is caused by a virus called Vibrio cholerae. The measures which can be taken for treatment of the disease are: Giving ORS-Oral rehydration solution to the patient and giving antibiotics prescribed by the doctor. The disease can be avoided by eating clean and hygienic food and timely immunisation against the disease.

Why Do we Fall Ill Class 9 Extra Questions Value Based (VBQs)

Question 1.
An HIV infected employee was dismissed from service by the employer. The colleagues of the employee in the office intervened and convinced the boss of the company to reinstate the services of the employee as HIV is not transmitted by mere physical contact. They told the employer that such person should not be made a victim of social stigma on contracting the disease.
(i) Name the disease which the employee was suffering from.
(ii) How does the disease get transmitted from one person to another?
(iii) What values are shown by the colleagues of the employee?
Answer:
(i) AIDS: Acquired immunodeficiency syndrome.

(ii) The disease gets transmitted by four ways:
(a) Sex with multiple partners.
(b) Transfusion of HIV contaminated blood.
(c) Use of HIV contaminated syringe.
(d) From infected mother to her child at the time of delivery of the baby.

(iii) The values shown by the colleague of the employee are: awareness, helpfulness, empathy and knowledge about their rights.

Question 2.
Rohit and’ Mayank are roommates in the hostel. Mayank is an avid reader of science magazines and articles. Mayank immediately took Rohit to a doctor when Rohit complained of tiredness, nausea, vomiting and pale eyes. What is the probable disease Rohit was suffering from? Name the causative microbe. What values are shown by Mayank?
Answer:
The symptoms of Rohit show that he was suffering from Jaundice. The microbe which causes the disease is virus. The values shown by Mayank are awareness, scientific temper, concern for others and helpful nature.

Question 3.
The parents of a new bom child were afraid to take their child for vaccination as someone told them that the vaccine contains harmful germs. However, when they consulted Dr. Shweta, she listened to them patiently and then cleared their doubts about vaccines. She told them that the vaccines only contain dead germs or inactivated germs which do not cause the disease. How do the dead germs in vaccines protect from diseases? What are the values shown by Dr. Shweta?
Answer:
The dead or the inactivated germs in the vaccines stimulate our immune system to develop antibodies against the disease causing microbes present in the vaccine and store the antibodies for action during any subsequent infection. In this way the vaccines provide immunity to the person against the disease. The values shown by Dr. Shweta are concern for others, helpfulness and patience.

Question 4.
Megha’s told her that he had been feeling tired, breathless, had persistent cough and blood was coming out in his sputum. She told him that these are symptoms of an infectious disease and advised him to consult a doctor. She also took him for diagnostic tests prescribed by the doctor. The helps was diagnosed as suffering from an infectious disease. He took the medicines prescribed by the doctor and got cured of the disease.
(i) Name the most likely disease and microbe from which the help suffered?
(ii) How does the disease get transmitted?
(iii) What are the values depicted by Megha?
Answer:
(i) The disease is most likely Tuberculosis caused by bacteria.

(ii) The disease gets transmitted when a healthy person inhales the droplets released into air by an infected person while coughing or sneezing.

(iii) Megha shows a helpful nature, scientific attitude, concern for others and sympathetic nature.

Question 5.
The municipality of an area advised the residents of the area to eliminate the breeding grounds of mosquitoes and use mosquito repellents in homes to avoid a disease which results in chills and recurring fever in patients. The children of the area formed teams which inspected the surrounding areas and put few drops of oil or petrol on stagnant water pools of the area.
(i) Name the disease, causative organism and the vector of the disease which was spreading in the area.
(ii) How do the drops of petrol or oil on stagnant water prevent the spread of the disease?
(iii) What are the values shown by the students?
Answer:
(i) The disease is Malaria caused by Plasmodium and transmitted by the vector female Anopheles mosquito.

(ii) The drops of oil or petrol in the stagnant water pools kill the larvae of the mosquito as they will not be able to breathe.

(iii) The values shown by the children are: public good, helpful attitude, scientific temper and work for social good.

In this page, we are providing Improvement in Food Resources Class 9 Extra Questions and Answers Science Chapter 15 pdf download. NCERT Extra Questions for Class 9 Science Chapter 15 Improvement in Food Resources with Answers will help to score more marks in your CBSE Board Exams. https://ncertmcq.com/extra-questions-for-class-9-science/

Class 9 Science Chapter 15 Extra Questions and Answers Improvement in Food Resources

Extra Questions for Class 9 Science Chapter 15 Improvement in Food Resources with Answers Solutions

Improvement in Food Resources Class 9 Extra Questions Very Short Answer Type

Improvement In Food Resources Class 9 Extra Questions And Answers Question 1.
What is the advantage of selecting seeds of crops with wider adaptability for agriculture?
Answer:
Wider adaptability helps in stabilizing crop production under different environmental conditions.

Class 9 Science Chapter 15 Extra Questions And Answers Question 2.
Name the type of nutrient that we get from mustard seeds and linseed.
Answer:
Mustard seeds and linseed are oilseed crops that provide fats.

Improvement In Food Resources Class 9 Notes Extra Questions And Answers Question 3.
Mention any two abiotic factors that affect crop production.
Answer:
Drought, salinity, waterlogging, heat, cold and frost are the abiotic factors that affect crop production.

Improvement In Food Resources Class 9 Important Questions Question 4.
Students were asked to select one that is not a source of starch amongst the following rice, wheat, sunflower seeds, and potato tuber.
Answer:
Sunflower seeds are not a source of starch. They are a source of fats.

Improvement In Food Resources Class 9 Questions And Answers Pdf Question 5.
Improved varieties can be produced in both animals and plants. How?
Answer:
Improved varieties can be produced in both animals and plants by hybridization and genetic modification.

Ch 15 Science Class 9 Extra Questions Question 6.
Name two protein-containing Rabi crops.
Answer:
Protein containing Rabi crops are gram and peas.

Improvement In Food Resources Class 9 Questions And Answers Question 7.
Identify two crops from the following which provide us carbohydrates for energy requirement. Black gram, wheat, lentil, and rice.
Answer:
Wheat and rice provide energy.

Improvement In Food Resources Class 9 Notes Questions And Answers Question 8.
Name two plants which are used as biopesticide in organic farming.
Answer:
Turmeric and leaves of Neem plant are used as biopesticide in organic farming.

Improvement In Food Resources Question Answer Question 9.
Name the two vitamins which are added in the poultry feed.
Answer:
Vitamin A and K are the vitamins that are added in the poultry feed.

Extra Questions From Chapter Improvement In Food Resources Question 10.
Name the major nutrient which we get from fish.
Answer:
The major nutrient which we get from fish is protein.

Class 9 Improvement In Food Resources Extra Questions Question 11.
How does Catla differ from Mrigal?
Answer:
Callas are surface feeders while Mrigals are bottom feeders.

Class 9 Science Ch 15 Extra Questions Question 12.
What is mariculture?
Or
What do you mean by mariculture?
Answer:
Mariculture is a practice in which marine fishes like mullets, bhetki, and pearl spots are cultured in coastal waters on a commercial scale.

Class 9 Chapter 15 Extra Questions Question 13.
Give one example of local variety and foreign variety of bees.
Answer:
Local variety: Apis cerana Indica is commonly known as the Indian bee.
Foreign variety: Apis mellifera is the Italian variety of bee.

Important Questions Of Improvement In Food Resources Question 14.
State one factor which affects the quality of honey produced.
Answer:
The quality of honey depends upon the pasturage or the flowers available to the bees for nectar and pollen collection.

Question 15.
Give two examples of exotic breeds of cows that are selected for a long lactation period.
Answer:
Exotic or foreign breeds like Jersey and Brown Swiss are selected for long lactation periods.

Question 16.
What is meant by beekeeping?
Answer:
Beekeeping is the practice of rearing the honeybees for obtaining honey and bee wax.

Question 17.
Which species of the honeybee is commonly used for commercial honey production throughout the country?
Answer:
Apis mellifera, the Italian variety of bee is commonly used for commercial honey production throughout the country.

Improvement in Food Resources Class 9 Extra Questions Short Answer Type 1

Question 1.
Mention the names of four marine fish of high economic value.
Answer:
Fishes like mullets, bhetki, pearl spots and prawns are of high economic value.

Question 2.
Give two examples of shellfishes.
Answer:
Shellfish include prawns, mussels and oysters.

Question 3.
Name two desirable traits for variety improvement in poultry farming.
Answer:
The two desirable traits for variety improvement in poultry farming are:

• number and quality of chicks;
• dwarf broiler parent for commercial chick production.

Question 4.
Which method is commonly used for improving cattle breeds and why?
Answer:
Crossbreeding between the indigenous and exotic breeds is commonly used for improving cattle breeds. This is done as it helps to incorporate the desirable qualities like a long lactation period of exotic breeds with the disease resistance of indigenous breeds in the progeny.

Question 5.
What are ‘Sahiwal’ and ‘Jersey’ breeds?
Answer:
Sahiwal is an indigenous breed of cow whereas Jersey is the exotic breed of cow.

Question 6.
State the food requirements of dairy animals.
Answer:
The food requirements of dairy animals are of two types:

• Maintenance requirement, which is the food required to support the animal to live a healthy life.
• Milk producing a requirement, which is the type of food required during the lactation period.

Question 7.
What is mixed cropping? How does it help a farmer?
Answer:
Mixed cropping is the practice of growing two or more crops simultaneously on the same piece of land. For example, wheat and gram, or wheat and mustard, or groundnut and sunflower. It helps the farmer as it reduces the risk and gives some insurance against the failure of one of the crops.

Question 8.
State two advantages of fertilizers over manure.
Answer:
Fertilizers are more advantageous than manure as:

• Fertilizers are nutrient specific and provide the specific nutrients like N, P, K to the soil.
• They are not bulky, so are easier to transport.

Question 9.
What do you mean by vermicompost?
Answer:
The compost prepared by using earthworms to hasten the process of decomposition of plant and animal refuse is called vermicompost.

Question 10.
What are the advantages of fish farming?
Answer:
The advantages of fish farming are:

• It helps to get a large amount of desired fishes from a small area.
• It enables a variety of improvement in a better way.

Question 11.
What is a GM crop? Name anyone such crop which is grown in India.
Answer:
GM crops are the crops obtained by introducing a gene that would provide the desired characteristic to the crop plant. Bt Cotton is a genetically modified (GM) crop which has been made insect-resistant by introducing a gene from bacteria.

Question 12.
Give any two differences between macronutrients and micronutrients.
Answer:
Macronutrient:

1. Macronutrients are generally present and utilized by plant tissues in large amounts.
2. Apart from carbon, hydrogen, oxygen, the macronutrients include six elements- nitrogen, phosphorous, sulfur, potassium, calcium, and magnesium.

Micronutrient

1. The nutrients which are needed by plant tissues in small amounts are called micronutrients.
2. These include seven elements: iron, manganese, copper, zinc, molybdenum, boron, and chlorine.

Question 13.
What is a green revolution?
Answer:
An increase in crop production (especially wheat and rice) due to the use of plant breeding techniques and better farming practices, is called the green revolution.

Question 14.
What are the weeds? How do they harm crop plants?
Or
How do they prevent the growth of crops?
Answer:
The unwanted plants which grow along with the crop in the cultivated field are called weeds. Weeds compete for food, space, and light with the crop plant and reduce the growth of the crop.

Question 15.

1. What are many animals?
2. Give two examples of such animals.

Answer:

1. Milk: producing females of cattle are called many animals (dairy animals).
2. Examples of such animals are: cows, buffaloes, goats etc.

Question 16.
Mention two advantages of animal husbandry.
Answer:
Animal husbandry is advantageous to get

1. Higher milk production from cattle and higher egg production from poultry.
2. Utilization of animal wastes in a beneficial way.

Question 17.
State two characteristics of a healthy animal.
Answer:
The two characteristics of a healthy animal are:

1. A healthy animal feeds regularly.
2. Healthy animals have a normal posture.

Question 18.
Why would a cattle breeder choose to cross-breed a Jersey cow with a Red Sindhi? State two reasons.
Answer:
Jersey cows have a longer lactation period while Red Sindhi are resistant to diseases. So, the two are cross-bred to get animals with

• Long lactation period
• Resistance to diseases.

Question 19.
How are new varieties of poultry birds with desired traits produced?
Answer:
Poultry birds with desired traits are produced by crossbreeding the indigenous variety like Aseel with the exotic variety like Leghorn.

Question 20.
What desirable traits are focussed to develop by cross-breeding indigenous and exotic breeds of fowl?
Or
Mention any four desirable traits for which new varieties are produced?
Answer:
Desirable traits of poultry are:

• number and quality of chicks;
• dwarf broiler parent for commercial chick production;
• summer adaptation capacity/tolerance to high temperature;
• low maintenance requirements;
• reduction in the size of the egg-laying bird with the ability to utilize more fibrous cheaper diets formulated using agricultural by-products.

Question 21.
1. State one demerit with a composite fish culture system.
2. How can this problem be overcome?
Answer:
1. The demerit of composite fish culture system is:
(a) Many of the fishes used in the composite culture system breed only during monsoon.
(b) Lack of availability of good quality seed.
2. The problem is overcome by breeding these fish in ponds using hormonal stimulation. This ensures the supply of pure fish seed in desired quantities.

Improvement in Food Resources Class 9 Extra Questions Short Answer Type 2

Question 1.
(a) Suppose you are in charge of a grain store. How will you find out the presence of pests? Mention any two indicators.
(b) Which method is most effective for destroying insects in stored food grains, spraying or fumigation?
Answer:
(a) The indicators for the presence of pests in grain store are:
(i) Damaged or broken grains having perforations or holes.
(ii) Discoloration of grains, degraded quality of food grains.
(b) Fumigation is a better method than spraying of chemicals as the fumigants completely fill the area with gaseous particles that suffocate the pests and kill them.

Question 2.
Write a short note on marine fisheries.
Answer:
Marine fishery resources include 7500 km coastline and the deep seas beyond it. Some marine fish varieties are pomfret, mackerel, tuna, sardines, and Bombay duck. Fishes like mullets, bhetki, and pearl spots; shellfish such as prawns, mussels, and oysters as well as seaweed are of high economic value.

Question 3.
Differentiate between:
1. Inland fishery and marine fishery
2. Apiculture and aquaculture
Or
Distinguish between
1. Inland fishery and marine fishery
2. Culture fishery and capture fishery
3. Apiculture and aquaculture
Answer:
Inland Fishery:

• Inland fishery resources include canals, ponds, reservoirs, rivers and brackish water resources like estuaries and lagoons.
• Most fish production from these resources is through aquaculture.

Marine Fishery:

• Marine fishery resources include 7500 km coastline and the deep seas beyond it.
• Most fish production from these resources is through mariculture.

Apiculture:
The practice of rearing and maintenance of honeybees for obtaining honey and bee wax is called as apiculture.

Aquaculture:
The practice of breeding, rearing, and harvesting of plants and animals in all types of water environments including ponds, rivers, lakes, and the ocean.

Capture fishery:
Fish are obtained from natural resources in capture fishery.

Culture fishery:
Fish farming done in ponds or tanks is called culture fishery.

Question 4.
Differentiate between layers and broilers. What type of food should be given to broilers?
Answer:
Layers:

• The egg-laying birds which are managed for egg production are called layers.
• The layers start laying eggs at the age of 20 weeks. So, they are kept for longer periods of, around 500 days, called laying period.
• They require enough space, proper light, and hygienic conditions.
• Their feed consists of vitamins, minerals, and certain micronutrients that affect the hatchability of the eggs.

Broilers:

• The birds maintained for meat production are called broilers.
• The broilers are raised in poultry farms up to 6-7 weeks and usually weigh around 700 g to 1.5 kg.
• More stress is given to maintain the feathering, carcass quality, and low levels of mortality.
• The requirement of the broilers is protein and fat-rich food. The level of vitamin A and vitamin K is kept high in their feed.

Question 5.
What are the advantages of bee-keeping?
Answer:
The advantages of bee-keeping are:

• It helps to obtain honey and bee wax which are used in medicines and many cosmetic preparations respectively.
• It requires a very low amount of investment.
•  It is less labor-intensive.
• It helps to increase the pollination of flowers.

Question 6.
What is honey? What does the quality of honey depend upon?
Answer:
It is a sugary substance produced and stored by insects like bees in the bee-hives. It has a very high nutritional and medicinal value. The value or quality of honey depends upon the pasturage, or the flowers available to the bees for nectar and pollen collection.

Question 7.
Differentiate between the following:

1. Capture fishery and culture fishery
2. Beekeeping and Poultry farming

Answer:

1. Capture fishery: Fish are obtained from natural resources in capture fishery.
   Culture fishery: Fish farming is called culture fishery.
2. Beekeeping is the practice of rearing honeybees for obtaining honey and bee wax.
   Poultry farming is undertaken to raise domestic fowl called layers for egg production and the broilers for chicken meat.

Question 8.
Discuss various methods of weed control.
Answer:
The various methods of weed control are:
Mechanical removal, a spray of chemicals called weedicides, and preventive methods like proper seedbed preparation, timely sowing of crops, intercropping, and crop rotation.

question 9.
Discuss the role of hybridization in crop improvement.
Answer:
Hybridization is one of the methods of crop production which ensures high yield. Hybridization refers to crossing between two genetically dissimilar plants each of which possesses a particular desired character. The two varieties are cross-bred during the process to incorporate both the desirable characteristics in a single variety. This method of hybridization improves crops with respect to yield, disease resistance, pest resistance, etc.

Question 10.
What are the macro and micronutrients of plants? Name two of each kind.
Answer:
Macronutrients: The nutrients which are required in large quantities. They are six.
Example: Nitrogen, Phosphorus.
Micronutrients: The nutrients which are required in small quantities. They are seven.
Example: Iron, Copper.

Question 11.
Name any three processes in plants that are affected by deficiency in nutrients.
Answer:
Deficiency of nutrients affects the following things in plants:

• reproduction
• growth
•  susceptibility to diseases.

Question 12.
Distinguish between intercropping and mixed cropping. List any two advantages of intercropping over mixed cropping.
Answer:
Mixed cropping Growing two or more crops simultaneously on the same piece of land.
Inter-cropping: Growing two or more crops simultaneously on the same field in a definite pattern.
Intercropping is better than mixed cropping because:

• The application of pesticides to individual crop is easier and done as per the need of the crop.
• Different crops can be separately harvested and threshed.

Question 13.
What is hybridization? How is it done?
Answer:
Hybridization refers to crossing between two genetically dissimilar plants each of which possesses a particular desired character. The two varieties are cross-bred during the process to incorporate both the desirable characteristics in a single variety. This method of hybridization improves crops with respect to yield, disease resistance, pest resistance, etc.

Question 14.
How are cultivation practices and crop yield related to weather?
Answer:
1. Agriculture in India is largely dependent on the monsoon. The success of crops in most areas is dependent on timely monsoons and sufficient rainfall spread through most of the growing season. Hence, poor monsoons cause crop failure.

2. The cultivation of different varieties of crops is dependent on abiotic stresses like droughts and floods situation in an area.

Question 15.
Name any three methods of irrigation and briefly describe them.
Or
(a) Describe any two irrigation systems adopted in India to supply water to agricultural lands.
(b) Write two advantages of building check dams.
Answer:
(a) The three different types of irrigation systems are:
Wells: There are two types of wells: dug wells and tube wells. In a dug well, water is collected from water-bearing strata. Tube wells can tap water from the deeper strata. From these wells, water is lifted by pumps for irrigation.

Canals: In this system canals receive water from one or more reservoirs or from rivers. The main canal is divided into branch canals having further distributaries to irrigate fields.

River Lift Systems: In this system, water is directly drawn from the rivers for supplementing irrigation in areas close to rivers.

The advantage of check dams are-

• Leads to an increase in groundwater levels.
• The check-dams stop the rainwater from flowing away and reduce soil erosion.

Question 16.
What factors may be responsible for losses of grains during storage? Give one example of both. Give one method/preventive measure to control such losses.
Or
What preventive and control measures should be taken before the storage of grains?
Answer:
Factors responsible for losses of grains during storage are:

• Biotic: insects, rodents, fungi, mites, and bacteria
• Abiotic: inappropriate moisture and temperatures in the place of storage.

Ways to reduce loss during storage of grains:

1. Proper treatment and systematic management of warehouses.
2. They include strict cleaning of the produce before storage.
3. Proper drying of the product first in sunlight and then in shade.
4. Fumigation using chemicals that can kill pests.

Question 17.
List six facilities that must be provided to cattle to ensure their good health and production of clean milk.
Answer:
Six facilities that must be provided to cattle to ensure their good health and production of clean milk are:

• The cattle should be housed in well-ventilated sheds,
• The floor of the cattle shed needs to be sloping so as to stay dry and to facilitate cleaning.
• The feeding of cattle should be carried out in a scientific manner. The feed should have:

(a) Roughage, which is largely fiber and
(b) Concentrates, which are low in fiber and have high levels of proteins and other nutrients.

• Leads to an increase in groundwater levels.
• The check-dams stop the rainwater from flowing away and reduce soil erosion.

Question 18.
What is the lactation period? Name two breeds of cattle that are selected for their lactation period. Why are they crossed with local breeds?
Answer:
The period of milk production after the birth of a calf is called the lactation period. Milk production can be increased by increasing the lactation period. Exotic or foreign breeds like Jersey and Brown Swiss are selected for long lactation periods. They (exotic breeds) are crossed with local breeds to get animals with the desired qualities of both the animals.

Question 19.
Which variety of honeybee is advantageous – Apis cerana indica or Apis mellifera and why?
Answer:
Apis mellifera, the Italian variety of bee is better than Apis cerana indica. It has the following advantages:

• They have high honey collection capacity.
• They sting somewhat less.
• They stay in a given beehive for long periods and breed very well.

Question 20.
Match the column A with column B

Answer:
(a) (ii) Surface feeders
(b) (iii) Middle-zone feeders
(c) (i) Bottom feeders
(d) (iv) Culture fishery

Question 21.
Fill in the blanks
(a) Pigeon pea is a good source of ………..
(b) Berseem is an important ………… crop.
(c) The crops which are grown in the rainy season are called ………… crops.
(d) ………… are rich in vitamins.
(e) ………… crop grows in the winter season.
Answer:
(a) protein
(b) fodder
(c) Kharif
(d) Vegetables
(e) Rabi

Question 22.
What is a GM crop? Name anyone such crop which is grown in India.
Answer:
GM crops are the crops obtained by introducing a gene that would provide the desired characteristic to the crop plant. Bt Cotton is a genetically modified (GM) crop which has been made insect-resistant by introducing a gene from bacteria.

Question 23.
List out some useful traits in the improved crop.
Answer:
Some useful traits of improved crops are:
(a) higher yield
(b) improved nutritional quality
(c) resistance to biotic and abiotic stresses
(d) change in maturity duration
(e) wide range of adaptability
(f) desired agronomic characteristics.

Question 24.
Why is organic matter important for crop production?
Answer:
Organic matter is important for crops production because:
(a) it helps in improving soil structure.
(b) it helps in increasing water holding capacity of sandy soil.
(c) It helps in drainage and in avoiding water logging in clayey soils.

Question 25.
Why is excess use of fertilizers detrimental for the environment?
Answer:
Excess use of fertilizers is detrimental for the environment as their residual and unused amounts become pollutants for air, water, and soil. The fertilizers get washed away in the nearby water bodies and cause excessive growth of algae and aquatic plants which can adversely affect the aquatic life and drain the oxygen from water bodies.

Question 26.
Give one word for the following:
(a) Farming without the use of chemicals as fertilizers, herbicides and pesticides is known as ……….
(b) Growing of wheat and groundnut on the same field is called as ……….
(c) Planting soybean and maize in alternate rows in the same field is called as ……….
(d) Growing different crops on a piece of land in pre-planned succession is known as ……….
(e) Xanthium and Parthenium are commonly known as ……….
(f) The causal organism of any disease is called as ……….
Answer:
(a) organic farming
(b) mixed cropping
(c) intercropping
(d) crop-rotation
(e) weeds
(f) pathogen

Question 27.
Match the following A and B

Answer:
(a) → (iii) Drought animals
(b) → (v) Aseel
(c) → (iv) The local breed of cattle
(d) → (i) Milk producing female
(e) → (ii) Broiler

Question 28.
If there is low rainfall in a village throughout the year, what measures will you suggest to the farmers for better cropping?
Answer:
If there is low rainfall in a village throughout the year, then the farmers will be suggested to:
(a) Cultivate crops varieties that are drought resistant and early maturing.
(b) Increase the humus content of the soil in order to increase its water holding capacity.

Question 29.
Group the following and tabulate them as energy-yielding, protein yielding, oil yielding, and fodder crop. Wheat, rice, berseem, maize, gram, oat, pigeon gram, sudangrass, lentil, soybean, groundnut, castor, and mustard.
Answer:

1. Energy yielding: wheat, rice, maize
2. Protein yielding: gram, pigeon gram, lentil, soybean
3. Oil yielding: groundnut, castor, mustard, soybean
4. Fodder crops: berseem, oat, sudangrass

Question 30.
Define the term hybridization and photoperiod.
Answer:
Hybridization is one of the methods of crop production which involves crossing between two genetically dissimilar plants each of which possesses a particular desired character. The photoperiod is the duration of sunlight available to the plant. It affects the growth, flowering, and maturation of crops.

Question 31.
Fill in the blanks
(a) Photoperiod affects the ………..
(b) Kharif crops are cultivated from ……….. to ………..
(c) Rabi crops are cultivated from ……….. to ………..
(d) Paddy, maize, green gram and black gram are ……….. crops.
(e) Wheat, gram, pea, mustard are ……….. crops.
Answer:
(a) Flowering of plants
(b) June to October
(c) November to April
(d) Khalil
(e) Rabi

Question 32.
Cultivation practices and crop yield are related to environmental conditions. Explain.
Answer:
Different crops and cultivation practices require different climatic conditions, temperature, photoperiod for their growth and completion of life cycle. Depending upon these conditions some crops called Kharif crops are grown in rainy season while others called as the Rabi crops are grown during winter season.

Question 33.
Fill in the blanks
(a) A total of ……….. nutrients are essential to plants.
(b) ……….. and ……….. are supplied by air to p1ants.
(c) ……….. is supplied by water to plants.
(d) Soil supply ……….. nutrients to plants.
(e) ……….. nutrients are required in large quantity and called.
(f) ……….. nutrients are needed in small quantity for plants and are called.
Answer:
(a) 16 (Sixteen)
(b) Carbon, oxygen
(c) Hydrogen
(d) 13 (Thirteen)
(e) Six, macro
(f) Seven, micro

Question 34.
Differentiate between compost and vermicompost.
Answer:
1. Compost: Compost is prepared by decomposition of the farm waste materials like livestock excreta (cow dung, etc.), vegetable waste, animal refuse, domestic waste, sewage waste, straw, eradicated weeds, etc., in pits.
2. Vermicompost: The compost is called as vermicompost if it is prepared by using earthworms to hasten the process of decomposition of plant and animal refuse.

Question 35.
Arrange these statements in the correct sequence of preparation of green manure.
(a) Green plants are decomposed in soil.
(b) Green plants are cultivated for preparing manure or crop plant parts are used.
(c) Plants are plowed and mixed into the soil.
(d) After decomposition, it becomes green manure.
Answer:
(b)→(c)→(a)→(d)

Question 36.
An Italian bee variety A. mellifera has been introduced in India for honey production. Write about its merits over other varieties.
Answer:
The Italian bee variety A. mellifera has the following advantages:

• They have high honey collection capacity.
• They sting somewhat less.
• They stay in a given beehive for long periods and breed very well.

Question 37.
In agricultural practices, higher input gives a higher yield. Discuss how.
Answer:
The financial conditions of the farmers allow them to take up different farming practices and technologies. The cropping system and production practices of the farmer are decided by the farmer’s purchasing capacity for input. A higher money input helps to raise the yield. So, we can say that in agricultural practices, higher input gives a higher yield.

Improvement in Food Resources Class 9 Extra Questions Long Answer Type

Question 1.
Mention the modern initiatives undertaken in India to supply water to the fields.
Answer:
Indian agriculture is mainly dependent on the monsoons. The irregular or scarcity of rainfall often results in crop failure. To overcome the problem, different types of irrigation systems are in practice in India for the supply of water in agricultural fields. Wells, canals, river lift systems, tanks, etc. are used for irrigation. Some new initiatives like rainwater harvesting and watershed management are being used.

For this small check-dams are constructed to stop the rainwater from flowing and lead to an increase in groundwater levels. The different types of irrigation systems are:

1. Wells: There are two types of wells – dug wells and tube wells. In a dug well, water is collected from water-bearing strata. Tube wells can tap water from the deeper strata. From these wells, water is lifted by pumps for irrigation.

2. Canals: In this system canals receive water from one or more reservoirs or from rivers. The main canal is divided into branch canals having further distributed to irrigate fields.

3. River Lift Systems: In this system, water is directly drawn from the rivers for supplementing irrigation in areas close to rivers.

4. Tanks: These are small storage reservoirs, which intercept and store the run-off of smaller catchment areas.

Question 2.
What do you understand by composite fish culture? Describe in detail with advantages and disadvantages. What are the advantages of composite fish culture?
Answer:
A combination of five or six fish species is used in a single fish pond in the composite fish culture system. The selected species do not compete for food among them as they have different types of food habits.

The types of fishes used are:
Callas are surface feeders, Rohus feed in the middle-zone of the pond, Mrigals, and Common Carps are bottom feeders, and Grass Carps feed on the weeds. As a result, the food available in all the parts of the pond is used.

Advantages of Composite fish culture:

• The species of fishes in the pond utilize all the food available in the pond.
• The species do not compete with each other for food as they have different food habits.
• The yield of fish is increased by such a culture system.

The disadvantage of Composite fish culture:
A major problem in fish farming is the lack of availability of good quality fish seeds.

Question 3.
How do plants get their nutrients?
Or
List the nutrients supplied by air, water, and soil.
Answer:

Question 4.
Define manures. What are its different kinds? State two limitations of manures.
Answer:
Manure is prepared by the decomposition of animal excreta and plant waste and contains a lot of organic matter which helps in enriching the soil with nutrients and increasing soil fertility. Manure is classified on the basis of kind of biological material used as:

1. Compost: Compost is prepared by decomposition of the farm waste materials like livestock excreta (cow dung etc.), vegetable waste, animal refuse, domestic waste, sewage waste, straw, eradicated weeds, etc., in pits.

2. Vermicompost: The compost is called vermicompost if it is prepared by using earthworms to hasten the proœss of decomposition of plant and animal refuse.

3. Green manure: Green plants like sun hemp or guar are grown and then mulched by plowing them into the soil prior to the sowing of the crop seeds to enrich the soil in nitrogen and phosphorus.

The limitations of manure are:

1. They do not supply a specific nutrient.
2. They are not readily soluble in water so their absorption by plants is slower.
3. They are bulky in nature and difficult to be transported.
4. Only small amounts of nutrients are supplied by the manure.

Question 5.
Differentiate between manures and fertilizers.
Or
Compare manure and fertilizer in three points.
Manure:

1. Manure is prepared by the decomposition of animal excreta and plant waste.
2. They are bulky and difficult to be transported.
3. They are not nutrient-specific in nature.
4. They are not readily soluble in water and thus absorbed slowly by plants.
5. Manure contains a lot of organic matter.
6. They are environment friendly in nature.
7. Difficult to store.

Fertilizer:

1. Fertilizers are commercially produced plant nutrients.
2. They are not bulky, so easier to transport.
3. They are nutrient-specific in nature.
4. They are easily absorbed by the plants as they are soluble in water.
5. They do not contain organic matter.
6. The comparatively less environmentally friendly.
7. Easier to store.

Question 6.
Mention the management practices that are common between dairy and poultry farming.
Answer:
Management practices which are common between dairy and poultry fanning are:

• Should be housed in the well-ventilated shelter.
• Proper cleanliness should be maintained.
• Regular visits by a doctor and timely vaccination.
• Balanced food should be provided with additives.
• Regular inspections, with proper record keeping.

Question 7.
What are the differences between broilers and layers with respect to their purpose of breeding and daily requirement? What necessary steps have to be taken to prevent the occurrence of infectious diseases in poultry farms?
Answer:
The meat-producing birds are called broilers and the egg-laying birds are called layers. The housing, nutritional and environmental requirements of the broilers are different from the layers. The broilers are raised in poultry farms up to 6-7 weeks and usually weigh around 700 g to 1.5 kg.

The requirement of the broilers is protein and fat-rich food. The level of vitamin A and vitamin K is kept high in their feed. Care is taken to avoid mortality and to maintain the feathering and carcass quality. The layers start laying eggs at the age of 20 weeks. So, they are kept for longer periods of around 500 days, called laying period. They require enough space, proper light, and hygienic conditions.

heir feed consists of vitamins, minerals, and certain micronutrients that affect the hatchability of the eggs. Necessary steps for prevention of infectious diseases are:
1. Proper cleaning, sanitation, and spraying of disinfectants at regular intervals.
2. Appropriate vaccination to prevent the occurrence of infectious diseases.

Question 8.
Discuss the role of hybridization in crop improvement.
Answer:
Hybridization is one of the methods of crop production which ensures high yield. Hybridization refers to crossing between two genetically dissimilar plants each of which possesses a particular desired character. The two varieties are cross-bred during the process to incorporate both the desirable characteristics in a single variety. This method of hybridization improves crops with respect to yield, disease resistance, pest resistance, etc.

Question 9.
Define
1. Vermicompost
2. Green manure
3. Biofertilizer
Answer:
1. Vermicompost: The compost prepared by using earthworms to hasten the process of decomposition of plant and animal refuse.
2. Green manure: The manure which is prepared by decomposing green plants in field itself is called green manure. For example: sun hemp is grown in fields, mulched by plowing and allowed to
decompose infield for the preparation of green manure. It helps in enriching the soil in nitrogen and phosphorus.
3. Biofertiliser: Living organisms which are used as fertilizer to supply the nutrients to plants, are called as biofertilizers. For example, blue-green algae which fix nitrogen in soil, rice fields, are called biofertilizers.

Question 10.
Discuss various methods of weed control.
Answer:
The various methods of weed control are mechanical removal, a spray of chemicals called weedicides and preventive methods like proper seedbed preparation, timely sowing of crops, intercropping and crop rotation.

Question 11.
Differentiate between the following

1. Capture fishery and Culture fishery
2. Mixed cropping and Inter-cropping
3. Beekeeping and Poultry farming

Answer:

1. Capture fishery: Fish are obtained from natural resources in capture fishery. Culture fishery: Fish farming is called culture fishery.
2. Mixed cropping: Growing two or more crops simultaneously on the same piece of land. Inter-cropping: Growing two or more crops simultaneously on the same field in a definite pattern.
3. Beekeeping is the practice to rear honeybee for obtaining honey. Poultry farming is undertaken to raise domestic fowl called layers for egg production and the broilers for chicken meat.

Question 12.
Give the merits and demerits of fish culture.
Answer:
The merits and demerits of fish culture are:
Merits:

• It helps to get a large amount of desired fishes from a small area.
• It enables a variety of improvements in a better way.

Demerits:

• It is a threat to bio-diversity as only selected varieties are cultured on a large scale.
• It involves the culture of only economically important and valued fishes.

Question 13.
What do you understand by composite fish culture?
Answer:
A combination of five or six fish species is used in a single fish pond in the composite fish culture system. The selected species do not compete for food among them as they have different types of food habits.

The types of fishes used are:
Callas are surface feeders, Rohus feed in the middle-zone of the pond, Mrigals and Common Carps are bottom feeders, and Grass Carps feed on the weeds. As a result, the food available in all the parts of the pond is used.

Question 14.
Why should beekeeping be done in good pasturage?
Answer:
Beekeeping should be done in good pasturage as it:

• Helps in increasing the honey yield.
• Helps in increasing pollination efficiency.
• Provides better quality and quantity of nectar for the honey bees.

Question 15.
Write the modes by which insects affect the crop yield.
Answer:
The modes by which insects affect the crop yield are

• they cut the root, stem and leaf,
• they suck the cell sap from various parts of the plant, and
• they bore into stem and fruits.

Question 16.
Discuss why pesticides are used in very accurate concentration and in a very appropriate manner.
Answer:
Pesticides should be used in very accurate concentration and in a very appropriate manner because it
may have the following adverse effects:
(a) They harm the soil and causes loss of fertility
(b) They act as a check on the replenishment of organic matter
(c) They kill the microorganism of soil and destroy the soil structure
(d) They cause air, water and soil pollution.

Question 17.
Name two types of animal feed and write their functions.
Answer:
The two types of animal feed are:

• Roughage, which is largely fiber.
• Concentrates, which are low in fiber and have high levels of proteins and other nutrients.

Question 18.
What would happen if poultry birds are larger in size and have no summer adaptation capacity? In order to get small sized poultry birds, having summer adaptability, what method will be employed?
Answer:
Maintenance of temperature is needed for better egg production by poultry birds. The egg production is declined due to larger size (increase in surface area of the body) and no adaptability of summer in poultry birds. So, cross-breeding of poultry birds is done to obtain smaller size and higher summer adaptability in them. Small size is ais? needed for better housing and lower feed requirements.

Question 19.
Suggest some preventive measures for the diseases of poultry birds.
Answer:
Some preventive measures of poultry bird diseases are
(a) cleaning of poultry farms
(b) proper sanitation of poultry farms
(c) spraying of disinfectants at regular intervals
(d) appropriate vaccination of birds.

Question 20.
The figure shows the two crop fields [Plots A and BI have been treated by manures and chemical fertilizers respectively, keeping other environmental factors same. Observe the graph and answer the following questions.

1. Why does plot B show a sudden increase and then a gradual decrease in yield?
2. Why is the highest peak in plot A graph slightly delayed?
3. What is the reason for the different patterns of the two graphs?

Answer:
1. With the addition of chemical fertilizer, there is a sudden increase in yield due to the release of nutrients Nitrogen, Phosphorus, Potassium (NPK), etc. in high quantity. The gradual decline in the graph may be due to continuous use and a high quantity of chemicals that kill microbes useful for replenishing the organic matter in soil. This decreases soil fertility.

2. Manures supply small quantities of nutrients to the soil slowly as it contains large amounts of organic matter. It enriches soil with nutrients thereby increasing soil fertility continuously.

3. The difference in the two graphs indicates that use of manure is beneficial for a long duration in cropping as the yield tends to remain high when the number of manure increases.

4. In the case of Plot B the chemical fertilizers may cause various problems when used continuously for long time. Loss of microbial activity reduces the decomposition of organic matter and as a result, the soil fertility is lost that affects the yield.

Question 21.
Complete the crossword puzzle

Across:
1. Oil yielding plant (9)
3. Crop grown in winter season (4)
5. Fixed by Rhizobium (8)
9. Common honey bee (4)

Down:
2. Animal feed (6)
4. A micronutrient (5)
6. Unwanted plant in crop fields (4)
7. An exotic breed of chicken(7)
8. Bottom feeders in fish pond(7)
10. A marine fish (4)
Answer:

Improvement in Food Resources Class 9 Extra Questions HOTS

Question 1.
Irrigation systems are in practice in India for the supply of water in agricultural fields. Why?
Answer:
Most agriculture in India is rain-fed and the success of crops in most areas is dependent on timely monsoons and sufficient rainfall. Poor monsoons can cause crop failure. Hence, in order to ensure that the crops get water at the right stages during their growing season, irrigation systems are in practice in India for the supply of water to agricultural fields.

Question 2.
Nitrogenous fertilizers are usually not required by the leguminous crops. Why?
Answer:
The leguminous crops have root nodules that harbor nitrogen-fixing bacteria like Rhizobium in them. These bacteria convert the atmospheric nitrogen to nitrates for their utilization by plants. So, nitrogenous fertilizers are usually not required by the leguminous crops.

Question 3.
Why are crops like guar grown by some farmers before sowing the seeds of a crop?
Answer:
The crops like guar are grown by farmers before sowing the seeds of a crop as the guar crop is mulched by plowing. It turns into green manure which helps in enriching the soil in nitrogen and phosphorus.

Question 4.
Why is the enhancement of food production becoming a major necessity? Which group of activities are required for improving the crop yields?
Answer:
Enhancement of food production has become a major necessity because:
1. The population of the world is increasing at a faster rate, so it is needed to fulfill the food requirements of the population.
2. The land available for cultivation is limited, so the only option available is to increase crop production.

Major groups of activities for improving crop yields:

• Crop variety improvement
• Crop production improvement
• Crop protection management

Question 5.
List some dairy farming practices needed to increase the milk yield potential of cattle.
Answer:
The dairy farming practices needed to increase the milk yield potential of cattle are:

1. The cattle should be housed well and have adequate water.
2. The cattle should be kept disease-free.
3. The feeding of cattle should be carried out in a scientific manner with special emphasis on the quality and quantity of fodder.
4. Stringent cleanliness and hygiene should be maintained.
5. Regular inspections of cattle should be done with proper record keeping.
6. Regular visits by a veterinary doctor should be ensured.

Improvement in Food Resources Class 9 Extra Questions Value Based (VBQs)

Question 1.
Aniket took admission in a dairy research institute and took an active interest in his studies. During the course, he got an opportunity to visit a village. He met the farmers there and advised them about dairy farm practices which can help to increase the milk yield of their cattle. The farmers were able to get an increased yield due to his advice.

1. Name two species of cattle in India.
2. List two measures that would have been suggested by Aniket to increase milk yield.
3. What values are shown by Aniket?

Answer:
1. Indian cattle belong to two different species, Bos indicus, cows, and Bos bubble.s, buffaloes.
2. The measures which would have been suggested by Aniket to increase milk yield are:
(a) The cattle should be housed well and have adequate water.
(b) The cattle should be kept disease-free.
(c) The feeding of cattle should be carried out in a scientific manner with special emphasis on the quality and quantity of fodder.
3. The values shown by Aniket are a concern for others, caring nature, scientific approach, and knowledge.

Question 2.
Sonam got admission in a reputed institute engaged in agricultural research. After the completion of course she decided to go and serve the people of her village. Her village was suffering from a reduction in infertility of the soil and high salinity in soil. She called a meeting of farmers and told them that the use of fertilizers has increased the salinity of the soil. She suggested to them the use of manures and cropping patterns to get better yields.

1. What are the different types of manures which can be used?
2. Name the different cropping patterns which she would have suggested.
3. What values are shown by Sonam?

Answer:

1. The types of manures which can be used are: Compost, vermicompost, and green manure.
2. The different cropping patterns can be inter-cropping, mixed cropping, and crop rotation.
3. The values shown by Sonam are sincerity towards work, scientific aptitude, and concern for others.

In this page, we are providing Motion Class 9 Extra Questions and Answers Science Chapter 8 pdf download. NCERT Extra Questions for Class 9 Science Chapter 8 Motion with Answers will help to score more marks in your CBSE Board Exams. https://ncertmcq.com/extra-questions-for-class-9-science/

Class 9 Science Chapter 8 Extra Questions and Answers Motion

Extra Questions for Class 9 Science Chapter 8 Motion with Answers Solutions

Motion Class 9 Extra Questions Very Short Answer Type

Motion Class 9 Extra Questions Question 1.
Define the following terms:
(a) Distance
(b) Displacement
(c) Speed
(d) Velocity
(e) Acceleration
(f) Uniform motion
(g) Uniform circular motion
(h) Scalar quantity
(i) Vector quantity
Answer:
(a) Distance: The total path length traveled by a body in a given interval of time is called distance.
(b) Displacement: The shortest distance measured from the initial to the final position of an object is known as displacement.
(c) Speed: The speed of a body is defined as the distance traveled per unit time.
(d) Velocity: Velocity is defined as displacement per unit time.
(e) Acceleration: The rate of change of velocity with respect to time.
(f) Uniform motion: A body moving in a straight line has a uniform motion if it travels the equal distance in equal intervals of tune.
(g) Non-uniform motion: A body has a non-uniform motion if it travels unequal distances in equal intervals of time.
(h) Scalar quantity: A physical quantity which is described completely by its magnitude only, is called a scalar quantity.
(i) Vector quantity: A physical quantity that has magnitude as well as direction and obeys the vector addition is called a vector quantity.

Motion Chapter Class 9 Extra Questions And Answers Question 2.
Draw position-time graph of a body that started from a position other than origin and moving with uniform speed.
Answer:

Class 9 Motion Extra Questions Question 3.
Give one example where the displacement is zero but the distance traveled is not zero.
Answer:
When a body completes one rotation in a circular path its initial and final positions are the same and hence its displacement is zero.

Class 9 Motion Numericals Extra Questions Question 4.
The area under the velocity-time curve represents which physical quantity?
Answer:
Distance and displacement.

Motion Extra Questions Class 9 Question 5.
Under what conditions, distance, and magnitude of the displacement are equal?
Answer:
Distance and displacement are equal fan object move along a straight line in one direction.

Class 9 Science Chapter 8 Extra Questions And Answers Question 6.
What is the numerical ratio of average velocity to the average speed of an object when it is moving in a straight path?
Answer:
In this case, both are equal, so the ratio is 1.

Motion Chapter Class 9 Extra Questions And Answers Numericals Question 7.
What does the speedometer of an automobile measure?
Answer:
The speedometer of a vehicle measures its instantaneous speed.

Extra Questions Of Motion Class 9 Question 8.
Classify the following quantities on the basis of scalar quantities and vector quantities.
(a) Distance
(b) Displacement
(c) Speed
(d) Velocity
(e) Acceleration
Answer:
(a) Distance: Scalar quantity
(b) Displacement: vector quantity
(c) Speed: Scalar quantity
(d) Velocity: Vector quantity
(e) Acceleration: Vector quantity

Extra Questions On Motion Class 9 Question 9.
An object starts with initial velocity y and attains a final velocity y. The velocity is changing at a uniform rate. What is the formula for calculating average speed in this situation?
Answer:

Extra Questions For Class 9 Physics Motion Question 10.
What will you say about the motion of an object if its distance-time graph is a straight line with having a constant angle with a time axis?
Answer:
The motion of the body is uniform motion (constant speed).

Class 9 Science Motion Extra Questions Question 11.
What will you say about the motion of a body if its velocity-time graph is a straight line parallel to the time axis?
Answer:
The velocity of the body is constant.

Class 9 Science Ch 8 Extra Questions Question 12.
A physical quantity measured is -20 ms^-1 It is speed or velocity?
Answer:
It is velocity because velocity can be positive or negative while speed cannot be negative.

Class 9 Physics Motion Extra Questions Question 13.
A motorcycle drives from A to B with a uniform speed of 30 kmh¹ and returns hack with a speed of 20 kmh¹. Find its average speed.
Answer:
Let distance AB = x km.
Time taken from going A to B; t₁ = \(\frac {x}{30}\) h
Time taken from goingBto A; t₂ = \(\frac {x}{20}\) h
Total time taken,t = t₁ + t₂ = \(\frac {x}{30}\) + \(\frac {x}{20}\) = \(\frac {x}{50}\) h
total distance = x + x = 2x km

∴ Average speed = 24 km/h

Ch 8 Science Class 9 Extra Questions Question 14.
A man swims in a pool of width 300 m. He covers 600 m in 10 minutes by swimming from on end to the other, and back along the same path. Find the average speed and average velocity of the man for the entire journey.
Answer:
Total distance covered by the man in 10 minutes = OA + AB = 600 m
Displacement of man in 10 minutes = 0 m

Average speed = 1 m/s

Average velocity = 0 m/s

Extra Questions For Class 9 Science Chapter Motion With Answers Question 15.
What is the acceleration of a body moving with uniform velocity along a straight line?
Answer:
Acceleration of the body is zero as the velocity is constant.

Question 16.
Give an example of a uniform circular motion.
Answer:
An athlete running on a circular track with constant speed.

Question 17.
Convert speed 54 km in meter per second.
Answer:
Speed = 54 km/h =54 x \(\frac{1000 m}{3600}\) = 15 m/s

Question 18.
What ¡s the nature of the distance-time graph for accelerated motion?
Answer:

Motion Class 9 Extra Questions Short Answer Type 1

Question 1.
Distinguish between speed and velocity.
Answer:
Speed:

• Speed is the ratio of distance and time.
• Speed is always positive
• Speed is a scalar quantity.

Velocity:

• Velocity is the ratio of displacement and time.
• Velocity may be negative or positive.
• Velocity is a vector quantity.

Question 2.
Distinguish between distance and displacement.
Answer:
Distance

• It is the actual length of the path covered by a moving body.
• It is always positive or zero.
• It is a scalar quantity.

Displacement:

• It is the shortest distance measured between the initial and final positions.
• It may be positive, negative, or zero.
• it is a vector quantity.

Question 3.
Write down the SI unit of the following quantities:
(a) Displacement
(b) Speed
(c) Velocity
(d) Acceleration
Answer:
(a) m
(b) m/s
(c) m/s
(d) m/s²

Question 4.
Distinguish between uniform motion and non-uniform motion.
Answer:
1. Uniform motion:
A body moving in a straight line has a uniform motion if it travels the equal distance in equal intervals of time

2. Non.uniform motion:
A body has a non-uniform motion if it travels the unequal distance in equal intervals of time

Question 5.
Distinguish speed at any instant and average speed.
Answer:
1. Instantaneous speed:
The speed at any particular instant is known as instantaneous speed.

2. Average speed:
Average speed is the ratio of total distance traveled by a body and time taken to travel that distance.

Question 6.
Draw a velocity versus time graph of a stone thrown vertically upwards and then coming downwards after attaining the maximum height.
Answer:
velocity-time graph

Question 7.
What is uniform circular motion? How is uniform circular motion regarded as an acceleration motion? Explain.
Answer:
When an object is moving in a circular path with a constant speed, the motion of an object is said to be uniform circular motion. When a body has a uniform circular motion, its velocity changes due to the continuous change in the direction of its motion. Hence, the motion of the body is accelerated motion.

Motion Class 9 Extra Questions Numericals

Question 8.
A person travels a distance of 4.0 m towards the east, then turns left and travels 3.0 m towards the north.
1. What is the total distance traveled by the person? North
2. What is his displacement?
Answer:
1. Total distance = OA + AB
= 4m + 3m
Total distance = 7m

2. Total displacement = OB = \(\sqrt{(O A)^{2}+(A B)^{2}}\)
=\(\sqrt{(4)^{2}+(3)^{2}}\) = \(\sqrt{25}\) = 5
Displacement = 5 m

Question 9.
A person travels on a semi-circular track of radius 50 m during a morning walk. If he starts from one end of the track and reaches the other end, calculates the distance traveled and displacement of the person.
Answer:
Let the person start moving from A and reach B via O.
The distance travelled by the person
= Length of track = πr
= \(\frac{22}{7}\) x 50 m = 157.14m
Distance = 157.14 m
The displacement is equal to the diameter of the semi-circular track joining A to B via O.
= 2r = 2 x 50 m = 100m
∴ Displacement = 100 m

Question 10.
Dinesh takes 20 minutes to cover a distance of 5 km on a bicycle. Calculate his average speed in
1. m/s
2. km/h
Answer:
1. Average speed in metre/second
Distance travelled by Dmesh = 5 km = 5 x 1000 m = 5000 m
time taken (t) = 20 min = 20 x 60 seconds = 1200 seconds

2. Average speed in kilometre/hour
Average speed = \(\frac{5 \mathrm{km}}{\frac{20}{60} \mathrm{h}}\) = 15 km/h
∴  Average speed = 15 km/h

Question 11.
A train starting from a railway station and moving with uniform acceleration attains a speed of 20 m/s in 10 seconds. Find its acceleration.
Answer:
Given,
initial velocity, u = 0 m/s
Final velocity, υ = 20 m/s
time taken, t = 10 s
Acceleration, a = \(\frac{v-u}{t}=\frac{20-0}{10}\)
∴ a = 2 m/s²

Question 12.
A car moving with a speed of 72 km/h is brought to rest in 10 seconds by applying brakes. Find the magnitude of average retardation due to brakes and distance traveled by car after applying the brakes.
Answer:
Given, initial velocity = 72 km/h = 72 x \(\frac{5}{18}\) = 20 m/s
Final velocity = 0 m/s
Time taken = 10s.

1. Retardation
Acceleration, a = \(\frac{υ – u}{t}\)
a = \(\frac{0 – 20}{10}\) = -2m/s²
∴ Retardation = 2 m/s²

2. Distance travelled using equation, υ² – u² = 2as
(0)² – (20)² = 2 (-2)s
∴ s = 100 m

Question 13.
The velocity of a particle moving along a straight line in a certain time interval is shown below. What is the distance traveled during acceleration?

Answer:
Here particle accelerates for 2 seconds.
Distance traveled during acceleration = area under υ – t graph for 2 sec.
\(\frac{1}{2}\) x Base x Height = \(\frac{1}{2}\) x 2 x 20 = 20m

Question 14.
A girl walks along a straight path to drop a letter in the letterbox and comes back to her initial position. Her displacement—
The time graph is shown in the figure. Plot a velocity-time graph for the same.
Answer:
Velocity-time graph

Question 15.
Obtain a relation for the distance traveled by an object moving with uniform acceleration in the time interval between the 4th and 5th seconds.
Answer:
Using equation, s = ut + \(\frac{1}{2}\) at²
Distance travelled in 5 s; s₁ = u x 5 + \(\frac{1}{2}\) a(5)²
s₁ = 5u + \(\frac{25a}{2}\)

Distance travelled in 4 s; s₂ = u x 4 + \(\frac{1}{2}\) a(4)²
s₂ = 4u x 8a
Distance travelled in the interval between 4^th and 5^th sec.
= s₁ – s₁ = (5u + \(\frac{25a}{2}\)) – (4u + 8a)
∴ Distance travelled = u + \(\frac{9a}{2}\)

Motion Class 9 Extra Questions Short Answer Type 2

Question 1.
Draw a position-time graph of for
(a) rest
(b) uniform motion
(c) Non-uniform motion
Answer:
(a) Position – time graph for rest

(b) Position – time graph for uniform motion

(c) Position – time graph for non-uniform motion

Question 2.
A draw velocity-time graph for
(a) Uniform motion
(b) Uniform acceleration
(c) Uniform retardation
Answer:
(a) Velocity – time graph for uniform motion (Const. speed)

(b) Velocity – time graph for uniform acceleration (Const. acceleration)

(c) Velocity – time graph for uniform retardation

Question 3.
Explain the difference between the two graphs.

Answer:
(a) In the first graph, the body is starting its motion from origin but in the second graph, the body is starting its motion from any other point.
(b) In the first graph, the body has zero initial velocity but in the second graph the body has non-zero initial velocity.

Question 4.
Two stones are thrown vertically upwards simultaneously with their initial velocities u1 and u2 respectively. Prove that the heights reached by them would be in the ratio of \(\frac{1}{2}\)
(Assume upward acceleration is – g and downward acceleration to be +g).
Answer:
The maximum height reached by the stone can be calculated by the formula
υ² – u² = 2as
Here, υ = 0 and a= – g
Applying this equation for the first ball

Motion Class 9 Extra Questions Numericals

Question 5.
Study the velocity-time graph of a traveling metro train as shown in the figure. What is the acceleration of the train
(a) during the first two seconds?
(b) between the second and tenth seconds?
(c) during the last two seconds?

Answer:
(a) Acceleration, a = \(\frac {v – u}{t}\)
Here, u = 0, u = 20m/s and t = 2s
a = \(\frac {20 – 0}{2}\) = 10 m/s²

(b) Here, u = 20m/s, υ = 20m/s and t = 8s
a = \(\frac {20 – 0}{2}\) = 0 m/s²

(c) Here, u = 20 m/s, u = 0 m/s and t = 2s
a = 0 – 20 = – 10 m/s²

Question 6.
An electron moving with a velocity of 5 x 10 ms¹ enters into a uniform electric field and acquires a uniform acceleration of 10 ms² in the direction of its initial motion.
1. Calculate the time in which the electron would acquire a velocity double its initial velocity.
2. How much distance would the electron cover in this time?
Answer:
Given, u =5 x 10 m/s²
a = 10⁴ m/s²

1. From υ = u + at
take υ = 2u
2u = u + at
u = at
5 x 10⁴ = 10⁴ x t
∴ t = 5s

2. From s = ut + \(\frac{1}{2}\) at²
s = 5 x 10⁴ x 5 + \(\frac{1}{2}\) x 10⁴ x (5)²
∴ s = 37.5 x 10⁴ m

Question 7.
The motion of a train is described by the velocity-time graph as shown in the figure given below.

Find distance travelled by car between
1. 0 to 20 s
2. 20 s to 50 s
Answer:
Distance travelled = Area of velocity – time curve
1. For (0 to 20 s)
Distance = Area of ΔOAC = \(\frac{1}{2}\) x OC x AC = \(\frac{1}{2}\) x 20 x 10 = 100 m

2. For (20 s to 50 s)
Distance = Area of rectangle ABDC + Area of ΔBED
Distance = AC x CD + \(\frac{1}{2}\) DE x DB = 10 x (40 – 20) + \(\frac{1}{2}\) x 10 x 5 = 225m

Motion Class 9 Extra Questions Long Answer Type

Question 1.
Derive an expression for three equations of motion for uniform accelerated motion graphically.
Answer:
Equation of motion by graphical method
Let us consider a body is moving with acceleration where u is initial velocity and u is final velocity, s is the displacement of object and t is a time interval.

1. υ = u + at
We know that slope of υ – t graph gives acceleration so slope
= a = \(\frac{v-u}{t-0}\)
a = \(\frac{v-u}{t}\)
∴ υ = u + at

2. s = ut + \(\frac{1}{2}\) at²
We know that area under u – t graph gives the displacement.
Area = s = area of triangle CDE + area of rectangle ABCE
s = ut + \(\frac{1}{2}\) x t x (υ – u) from (υ – u = at)
Putting the value of υ – u
s = ut + \(\frac{1}{2}\) at²

3. υ² – u² = 2as
We know that area under υ – t graph gives displacement
Area = s = area of trapezium ABDE
s = \(\frac{1}{2}\) x (υ+u) x t From I (t = \(\frac{υ – u}{a}\))
Putting the value of t.
υ² – u² = 2as

Motion Class 9 Extra Questions HOTS

Question 1.
The distance-time graph of two trains is given below. The trains start simultaneously in the
same direction.
1. How much ahead of A is B when the motion starts?
2. What is the speed of B ?
3. When and where will A catch B?
4. What is the difference between speeds of A and B?

5. Is the speed of both the trains uniform or non-uniform? Justify your answer.

Answer:

1. 100km
2. Speed of B, υ = \(\frac{x_{2}-x_{1}}{t}\) = \(\frac{150-100}{2-0}\) = 25 km/h
3. After 2 hours, A catches B at 2. i.e.,150 km from origin 0.
4. The slope of the distance-time graph of A is greater than that of B. Therefore, the speed of A is greater than
   speed B. Speed of A = Slope of OQ = \(\frac{150}{2}\) = 75 km/h
   Difference between speed of A and B =75 km/h – 25 km/h = 50 km/h
5. The speed of both trains is uniform.

Question 2.
A car starts from rest and moves along the x-axis with constant acceleration 5 ms2 for 8 seconds. If it then continues with constant velocity, what distance will the car cover in 12 seconds since it started from rest?
Answer:
Given,
u = 0, a = 5ms^-2, t₁ = 8s and t₂ = 12s.
Total distance = distance travelled during acceleration + distance travelled during constant velocity
s = s₁ + s₂

For S₁
s₁ = u₁t₁ + \(\frac{1}{2}\) \(a t_{1}^{2}\)
s₁ = \(\frac{1}{2}\) x 5 x (8)²
s₁ = 160 m

For S₁
Applying υ = u + at
υ = 0 + (5 x 8)
u = 40 m/s
s₁ = ut₂
s₂ = 40 x 12
s₂ = 480 m
Total distance, s = s₁ + s₂
s = 160 + 480 = 640m

Question 3.
An object is dropped from rest at a height of 150 m and simultaneously another object is dropped from rest at a height 100 m. What is the difference in their heights after 2s if both the objects drop with the same acceleration? How does the difference in heights vary with time?
Answer:
At t = 0, difference in heights of two stones A and B
= 150 – 100 = 50 m
In t = 2s, distance through which each stone falls is –
s = ut + \(\frac{1}{2}\) at² = 0 x \(\frac{1}{2}\) x 10 x (2)² = 20m
∴ Difference in heights of two stones A and B
= (150 – 20) – (100 – 20) = 50
The difference in heights will remain the same at all times during their fall.

Question 4.
An object starting from rest travels 20 m in the first 2s and 160 m in the next 4s. What will be the velocity after 7s from the start?
Answer:
Given, the object travels 20 m first 2 s and 160 m in the next 4s.
From s = ut + \(\frac{1}{2}\) at²
In first 2 s, s = 20 m
20 = 0 + \(\frac{1}{2}\) a(2)²
20 = 2 a
∴ a = 10 m/s²
Velocity at the end of 2s is υ = u + at
υ = 0 + 10 x 2 = 20 m/s

In next 4 s,
s = ut + \(\frac{1}{2}\) a’t²
160 = 20 x 4 + \(\frac{1}{2}\) a’(4)²
80 = 8 a’
a’ = 10 m/s²

Motion Class 9 Extra Questions Value Based (VBQs)

Question 1.
Sumeet and Jaikishan are close friends. Sumeet is a science graduate and Jaikishan is a commerce graduate. Sumeet finds that while driving on a clear highway, Jaikishan often exceeds the speed limit and argues that there is no harm in doing so when the road is clear. Sumeet does not agree with him and tells him that with an increase in speed, the stopping distance of the car would increase and he would not be able to manage if someone appears suddenly on the way.
Read the above passage and answer the following questions:

1. is Sumeet right in his statement?
2. What values are displayed by Sumeet in his statement?
3. How is stopping distance related to the speed of the vehicle?

Answer:

1. Yes, Sumeet is absolutely right.
2. Sumeet is an intelligent boy and he can apply his knowledge of science in daily life.
3. Stopping distance (velocity)²

Question 2.
Raju and Raman are close friends. One day they went for a picnic. Raju was driving the car. When Raman saw the speedometer, he found that the speed of the car was more than the allowed speed limit. Raman advised Raju to reduce speed to avoid the punishment of Overspeed.
Answer the following questions:

1. What is the function of the speedometer?
2. What values are displayed by Raman?

Answer:

1. Speedometer provides instantaneous speed. B
2. Raman is a careful and law-abiding person.

Question 3.
Three friends Ram, Mohan, and Roy have to reach point B from point A. The path taken by them is shown in the figure.
Answer the following questions:

1. Distinguish between distance and displacement.
2. If all of them travel at the same speed, who will reach first at point B and why?
   

Answer:
1. Distance:

1. It is the actual length of the path covered by a moving body.
2. It is always positive or zero.
3. It is a scalar quantity.

Displacement:

1. It is the shortest measured distance between the initial and final positions.
2. It may be positive, negative, or zero.
3. It is a vector quantity.

2.  Mohan will reach first as he is traveling the shortest path.