Category: CBSE Class 7

NCERT Solutions for Class 7 Science Chapter 5 Acids, Bases and Salts are part of NCERT Solutions for Class 7 Science. Here we have given NCERT Solutions for Class 7 Science Chapter 5 Acids, Bases and Salts.

Board	CBSE
Textbook	NCERT
Class	Class 7
Subject	Science
Chapter	Chapter 5
Chapter Name	Acids, Bases and Salts
Number of Questions Solved	11
Category	NCERT Solutions

NCERT Solutions for Class 7 Science Chapter 5 Acids, Bases and Salts

Question 1.
State differences between acids and bases.
Answer:

Acids	Bases
1. Acids are sour to taste	1. Bases are bitter to taste.
2. Acids turn blue litmus red.	2. Bases turn red litmus blue.
3. Acid is defined as a substance which contains hydrogen ion.	3. A base is defined as a substance which contains hydroxyl ion.

 Question 2.
Ammonia is found in many household products, such as window cleaners. It turns red litmus blue. What is its nature?
Answer:
Ammonia has basic nature.

Question 3.
Name the source from which litmus solution is obtained. What is the use of this solution?
Answer:
The extraction of litmus solution takes place from Lichens (a symbiotic association of algae and fungi). It is used to determine whether the given solution is acidic or basic.

Question 4.
Is the distilled water acidic, basic, or neutral? How would you verify it?
Answer:
Distilled water is neutral. We can verify it by showing that neither blue nor red litmus paper changes its colour when dipped in it.

Question 5.
Describe the process of neutralization with the help of an example.
Answer:
The process in which an acid reacts with a base to form salt and water is known as a neutralization reaction. For example,

Question 6.
Mark ‘T’ if the statement is true and ‘F’ if it is false :
(i) Nitric acid turns red litmus blue. (T/F)
(ii) Sodium hydroxide turns blue litmus red. (T/F)
(iii) Sodium hydroxide and hydrochloric acid neutralize each other and form salt and water. (T/F)
(iv) Indicator is a substance which shows different colours in acidic and basic solutions. (T/F)
(v) Tooth decay is caused by the presence of a base. (T/F)
Answer:
(i) F
(ii) F
(iii) T
(iv) T
(v) F

Question 7.
Dorji has a few bottles of soft drink in his restaurant. But, unfortunately, these are not labelled. He has to serve the drinks on the demand of customers. One customer wants acidic drink, another wants basic and third one wants a neutral drink. How will Dorji decide which drink is to be served to whom?
Answer:
He can decide by the use of an indicator. If the sample of drink turns red litmus blue, it is basic. If it turns blue litmus red, it is acidic. If it does not affect litmus, it is neutral.

Question 8.
Explain why :
(a) An antacid tablet is taken when you suffer from acidity.
(b) Calamine solution is applied on the skin when an ant bites.
(c) Factory waste is neutralised before disposing it into the water bodies.
Answer:
(a) To relieve indigestion, we take an antacid such as milk of magnesia. It neutralizes the effect of excessive acid.
(b) When an ant bites, it injects the acidic liquid into the skin. This acidic liquid is formic acid, which leads to inflammation to the skin. The effect of the sting can be neutralised by rubbing calamine solution which contains zinc carbonate. The zinc carbonate is a weak base and causes no harm to the skin.
(c) The wastes of many factories usually contain acids. If they are allowed to flow into the water bodies without neutralising it properly, then the acids will kill fish and other aquatic organisms. So factory wastes must be neutralised by adding some basic substances into the wastes before disposing these into water bodies.

Question 9.
Three liquids are given to you. One is hydrochloric acid, another is sodium hydroxide and third is a sugar solution. How will you identify them? You have only a turmeric indicators.
Answer:

S.No.	Name of substance	Effect on turmeric indicator
1.	Hydrochloric acid	The yellow colour of turmeric turns blue
2.	Sodium hydroxide	The yellow colour of turmeric turns red
3.	Sugar solution	No change in turmeric colour

Question 10.
Blue litmus paper is dipped in a solution. It remains blue. What is the nature of the solution? Explain.
Answer:
The solution may be neutral or basic. Both types of substances have no effect on blue litmus. Put a drop of this solution on a red litmus paper. If it turns blue, then the above solution is basic in nature and if no colour change occurs, then it is neutral.

Question 11.
Consider the following statements:
(a) Both acids and bases change colour of all indicators.
(b) If an indicator gives a colour change with an acid, it does not give a change with a base.
(c) If an indicator changes colour with a base, it does not change colour with an acid.
(d) Change of colour in acid, and a base depends on the type of the indicator.
Which of these statements are correct?
(i) All four
(ii) (a) and (d)
(iii) (b) and (c)
(iv) Only (d)
Answer:
(ii) (a) and (d)

We hope the NCERT Solutions for Class 7 Science Chapter 5 Acids, Bases and Salts help you. If you have any query regarding NCERT Solutions for Class 7 Science Chapter 5 Acids, Bases and Salts, drop a comment below and we will get back to you at the earliest.

NCERT Solutions for Class 7 Science Chapter 4 Heat are part of NCERT Solutions for Class 7 Science. Here we have given NCERT Solutions for Class 7 Science Chapter 4 Heat.

Board	CBSE
Textbook	NCERT
Class	Class 7
Subject	Science
Chapter	Chapter 4
Chapter Name	Heat
Number of Questions Solved	11
Category	NCERT Solutions

NCERT Solutions for Class 7 Science Chapter 4 Heat

Question 1.
State similarities and differences between the laboratory thermometer and the clinical thermometer.
Answer:
Similarities:

1. Both contain mercury in bulbs.
2. Both use the Celsius scale on a glass tube.

Differences:

1. The temperature on the laboratory thermometer falls by itself, but not so in the clinical thermometer.
2. The range of a laboratory thermometer is much higher than a clinical thermometer.

Question 2.
Give two examples each of conductors and insulators of heat.
Answer:

• Conductors of heat: Copper, iron.
• Insulators: Plastic, wood (dry).

Question 3.
Fill in the blanks:

1. The hotness of an object is determined by its …….
2. The temperature of boiling water cannot be measured by a ………. thermometer.
3. Temperature is measured in degree …………
4. No medium is required for transfer of heat by the process of ………..
5. A cold steel spoon is dipped in a cup of hot milk. It transfers heat to its other end by the process of ………
6. Clothes of ……….. colours absorb heat better than clothes of light colours.

Answer:

1. temperature
2. clinical
3. Celsius
4. radiation
5. conduction
6. dark

Question 4.
Match the following:

(i) Land breeze blows during	(a) summer
(ii) Sea breeze blows during	(b) winter
(iii) Dark-coloured clothes are preferred during	(c) day
(iv) Light-coloured clothes are preferred during	(d) night

Answer:

(i) Land breeze blows during	(d) night
(ii) Sea breeze blows during	(c) day
(iii) Dark-coloured clothes are preferred during	(b) winter
(iv) Light-coloured clothes are preferred during	(a) summer

Question 5.
Discuss why wearing more layers of clothing during winter keeps us warmer than wearing just one thick piece of clothing.
Answer:
If there are more than one layer of clothes, air would be trapped in between them. Air is a poor conductor of heat. This increases the insulation and thus comfortability of the clothes as a whole.

Question 6.
Look at Fig., mark where the heat is being transferred by conduction, by convection, and by radiation.

Fig. Heat transferred by conduction, by convection and by radiation
Answer:
In this figure, the heat is transferred at three points in different ways:

• by radiation: from the flame to the bottom of the pan.
• by conduction: from lower surface to upper surface of the pan.
• by convection: from the base to the upper region of pan water.

Question 7.
In places of the hot climate, it is advised that the outer walls of houses be painted white. Explain.
Answer:
Objects with white surfaces reflect more heat and absorb less. So, less heat from outside would enter the house.

Question 8.
One liter of water at 30°C is mixed with one liter of water at 50°C. The temperature of the mixture will be
(a) 80°C
(b) more than 50°C but less than 80°C
(c) 20°C
(d) between 30°C and 50°C
Answer:
(d) between 30°C and 50°C.

Question 9.
An iron ball at 40°C is dropped in a mug containing water at 40°C. The heat will
(a) flow from the iron ball to water.
(b) not flow from iron ball to water or from water to iron ball.
(c) flow from water to iron ball.
(d) increase the temperature of both.
Answer:
(b) not flow from iron ball to water or from water to iron ball.

Question 10.
A wooden spoon is dipped in a cup of ice cream. Its other end
(a) becomes cold by the process of conduction.
(b) becomes cold by the process of convection.
(c) becomes cold by the process of radiation.
(d) does not become cold,
Answer:
(d) does not become cold.

Question 11.
Stainless steel pans are usually provided with copper bottoms. The reason for this could be that
(a) copper bottom makes the pan more durable.
(b) such pans appear colourful.
(c) copper is a better conductor of heat than stainless steel.
(d) copper is easier to clean than stainless steel.
Answer:
(c) copper is a better conductor of heat than stainless steel.

We hope the NCERT Solutions for Class 7 Science Chapter 4 Heat help you. If you have any query regarding NCERT Solutions for Class 7 Science Chapter 4 Heat, drop a comment below and we will get back to you at the earliest.

NCERT Solutions for Class 7 Science Chapter 3 Fibre to Fabric are part of NCERT Solutions for Class 7 Science. Here we have given NCERT Solutions for Class 7 Science Chapter 3 Fibre to Fabric.

Board	CBSE
Textbook	NCERT
Class	Class 7
Subject	Science
Chapter	Chapter 3
Chapter Name	Fibre to Fabric
Number of Questions Solved	9
Category	NCERT Solutions

NCERT Solutions for Class 7 Science Chapter 3 Fibre to Fabric

Question 1.
You must be familiar with the following nursery rhymes:
(i) ‘Baa baa black sheep, have you any wool.
(ii) ‘Mary had a little lamb, whose fleece was white as snow.
Answer the following:
(a) Which parts of the black sheep have wool?
(b) What is meant by the white fleece of the lamb?
Answer:
(a) The hairy skin – called fleece, has wool in black sheep.
(b) White fleece means hairy skin which is white in colour.

Question 2.
The silkworm is (a) a caterpillar, (b) a larva. Choose the correct option.
(i) (a)
(ii) (b)
(iii) both (a) and (b)
(iv) neither (a) nor (b)
Answer:
(iii) both (a) and (b)

Question 3.
Which of the following does not yield wool?
(i) Yak
(ii) Camel
(iii) Goat
(iv) Woolly dog
Answer:
(iv) Woolly dog

Question 4.
What is meant by the following terms?

1. Rearing
2. Shearing
3. Sericulture

Answer:

1. Rearing: Bringing up and looking after the sheep is called rearing.
2. Shearing: To obtain wool, the fleece of the sheep along with a thin layer of skin is removed from its body. This process is called shearing.
3. Sericulture: The rearing of silkworms for obtaining silk is called sericulture.

Question 5.
Given below is a sequence of steps in the processing of wool. Which are the missing steps? Add them.
Shearing, ……., sorting ………, ………., ……….
Answer:
Shearing, scouring, sorting, picking out burrs, colouring, rolling.

Question 6.
Make sketches of the two stages in the life history of the silk moth which are directly related to the production of silk.
Answer:

Question 7.
Out of the following, which are the two terms related to silk production?
Sericulture, floriculture, moriculture, apiculture and silviculture.
Hints:
(i) Silk production involves the cultivation of mulberry leaves and rearing silkworms.
(ii) Scientific name of mulberry is Morus alba.
Answer:
Sericulture, Moriculture.

Question 8.
Match the words of Column I with those given in Column II:

Column I	Column II
1. Scouring	(a) Yields silk fibres
2. Mulberry leaves	(b) Wool yielding animal
3. Yak	(c) Food of silkworm
4. Cocoon	(d) Reeling
	(e) Cleaning sheared skin

Answer:

Column I	Column II
1. Scouring	(e) Cleaning sheared skin
2. Mulberry leaves	(c) Food of silkworm
3. Yak	(b) Wool yielding animal
4. Cocoon	(a) Yields silk fibres

Question 9.
Given below is a crossword puzzle based on this lesson. Use hints to fill in the blank spaces with letters that complete the words.

Down
(D) 1 : Thorough washing
2 : Animal fibre
3 : Long thread like structure
Across
(A) 1 : Keeps warm
2 : Its leaves are eaten by silkworms
3 : Hatches from egg of moth
Answer:

We hope the NCERT Solutions for Class 7 Science Chapter 3 Fibre to Fabric help you. If you have any query regarding NCERT Solutions for Class 7 Science Chapter 3 Fibre to Fabric, drop a comment below and we will get back to you at the earliest.

NCERT Solutions for Class 7 Science Chapter 2 Nutrition in Animals are part of NCERT Solutions for Class 7 Science. Here we have given NCERT Solutions for Class 7 Science Chapter 2 Nutrition in Animals.

Board	CBSE
Textbook	NCERT
Class	Class 7
Subject	Science
Chapter	Chapter 2
Chapter Name	Nutrition in Animals
Number of Questions Solved	13
Category	NCERT Solutions

NCERT Solutions for Class 7 Science Chapter 2 Nutrition in Animals

Question 1.
Fill in the blanks:

1. The main steps of nutrition in humans are ……., ………., ………., ………, and ………….
2. The largest gland in the human body is ………..
3. The stomach releases hydrochloric acid and ……… juices which act on the food.
4. The inner wall of the small intestine has many finger-like outgrowths called ……….
5. Amoeba digests its food in the ………..

Answer:

1. ingestion, digestion, absorption, assimilation, and egestion.
2. liver
3. digestive
4. villi
5. food vacuole.

Question 2.
Mark ‘T’ if the statement is true and ‘F’ if it is false:

1. Digestion of starch starts in the stomach. (T/F)
2. The tongue helps in mixing food with saliva. (T/F)
3. The gall bladder temporarily stores bile. (T/F)
4. The ruminants bring back swallowed grass into their mouth and chew it for some time. (T/F)

Answer:

1. F
2. T
3. T
4. T

Question 3.
Tick (√) mark the correct answer in each of the following:
(a) Fat is completely digested in the
(i) stomach
(ii) mouth
(iii) small intestine
(iv) large intestine

(b) Water from the undigested food is absorbed mainly in the
(i) stomach
(ii) food pipe
(iii) small intestine
(iv) large intestine
Answer:
(a) (iii) Small intestine
(b) (iv) Large intestine.

Question 4.
Match the items of Column I with those given in Column II:

Column I	Column II
Food components	Product(s) of digestion
Carbohydrates	Fatty acids and glycerol
Proteins	Sugar
Fats	Amino acids

Answer:

Column I	Column II
Food components	Product(s) of digestion
Carbohydrates	Sugar
Proteins	Amino acids
Fats	Fatty acids and glycerol

Question 5.
What are villi? What are their location and function?
Answer:
The inner walls of the small intestine have thousands of finger-like outgrowths. These are called villi. Villi are located in the small intestine. The villi increase the surface area for absorption of the digested food. Each villus has a network of thin and small blood vessels close to its surface. The surface of the villi absorbs the digested food materials.

Question 6.
Where is the bile produced? Which component of the food does it help to digest?
Answer:
Bile is produced in the liver. The bile juice is stored in a sac called the gall bladder. Bile plays an important role in the digestion of fats.

Question 7.
Name the type of carbohydrate that can be digested by ruminants but not by humans. Give the reason also.
Answer:
Cellulose is a type of carbohydrate that can be digested by ruminants but not by humans. Ruminants have a large sac-like structure called rumen which is present in between the small intestine and large intestine. The cellulose is digested here by the action of certain bacteria which are not present in humans.

Question 8.
Why do we get instant energy from glucose?
Answer:
Because glucose can easily breakdown in the cell with the help of oxygen and gives carbon dioxide, water, and energy.

Question 9.
Which part of the digestive canal is involved in:

1. absorption of food ……..
2. chewing of food …….
3. the killing of bacteria …….
4. complete digestion of food ………
5. formation of faeces ……..

Answer:

1. Small intestine
2. Mouth
3. Stomach
4. Small intestine
5. Large intestine.

Question 10.
Write one similarity and one difference between the nutrition in amoeba and human beings.
Answer:

1. Similarity: Both amoeba and humans use digestive juices to digest food.
2. Difference: Human needs to chew food, whereas, an amoeba, there is no chewing.

Question 11.
Match the items of Column I with suitable items in Column II

Column I	Column II
(a) Salivary gland	(i) Bile juice secretion
(b) Stomach	(ii) Storage of undigested food
(c) Liver	(iii) Saliva secretion
(d) Rectum	(iv) Acid release
(e) Small intestine	(v) Digestion is completed
(f) Large intestine	(vi) Absorption of water
	(Vii) Release of faeces

Answer:

Column I	Column II
(a) Salivary gland	(iii) Saliva secretion
(b) Stomach	(iv) Acid release
(c) Liver	(i) Bile juice secretion
(d) Rectum	(ii) Storage of undigested food
(e) Small intestine	(v) Digestion is completed
(f) Large intestine	(vi) Absorption of water

 Question 12.
Label figure of the digestive system.
Answer:

Fig. Human digestive system

Question 13.
Can we survive only on raw, leafy vegetables/grass? Discuss.
Answer:
No. Because to live a healthy life, we need a complete balance of all nutrients. Raw leafy vegetables/grass may have cellulose which can not be digested by us. So, we cannot survive only on raw, leafy vegetables/grass.

We hope the NCERT Solutions for Class 7 Science Chapter 2 Nutrition in Animals help you. If you have any query regarding NCERT Solutions for Class 7 Science Chapter 2 Nutrition in Animals, drop a comment below and we will get back to you at the earliest.

NCERT Solutions for Class 7 Science Chapter 9 Soil are part of NCERT Solutions for Class 7 Science. Here we have given NCERT Solutions for Class 7 Science Chapter 9 Soil.

Board	CBSE
Textbook	NCERT
Class	Class 7
Subject	Science
Chapter	Chapter 9
Chapter Name	Soil
Number of Questions Solved	10
Category	NCERT Solutions

NCERT Solutions for Class 7 Science Chapter 9 Soil

Tick the most suitable answer in questions 1 and 2.
Question 1.
In addition to the rock particles, the soil contains
(i) air and water
(ii) water and plants
(iii) minerals, organic matter, air and water
(iv) water, air and plants
Answer:
(iii) minerals, organic matter, air and water

Question 2.
The water holding capacity is the highest in
(i) sandy soil
(ii) clayey soil
(iii) loamy soil
(iv) mixture of sand and loam
Answer:
(ii) clayey soil

Question 3.
Match the items in Column I with those in Column II :

Column I	Column II
(i) A home for living organisms	(a) Large particles
(ii) Upper layer of the soil	(b) All kinds of soil
(iii) Sandy soil	(c) Dark in colour
(iv) Middle layer of the soil	(d) Small particles and packed tight
(v) Clayey soil	(e) Lesser amount of humus

Answer:

Column I	Column II
(i) A home for living organisms	(b) All kinds of soil
(ii) Upper layer of the soil	(c) Dark in colour
(iii) Sandy soil	(a) Large particles
(iv) Middle layer of the soil	(e) Lesser amount of humus
(v) Clayey soil	(d) Small particles and packed tight

Question 4.
Explain how soil is formed?
Answer:

1.  The big and heavy rocks are broken into smaller pieces that come on the surface of the earth.
2. Soil is formed by breaking down of rocks by the action of wind, water, and climate. This process is called weathering.
3.  The smaller particles of the rocks obtained due to weathering get further decomposed on long exposure to air and moisture.
4.  Finally, the decomposed parts of dead plants and animals get mixed up with soil formed by the above processes. This gives the soil enough energy in the form of organic matter.

Question 5.
How is clayey soil useful for crops?
Answer:
Clayey soil retains water to a great extent. Thus the crops which require more water grow well in clayey soil.

Question 6.
List the differences between clayey soil and sandy soil.
Answer:

Clayey Soil	Sandy Soil
1.Proportion of fine particles is large.	1.Proportion of big particles is large.
2. Has least percolation rate of water.	2. Has largest percolation rate of water.
3. Has good water holding capacity.	3. Has poor water holding capacity.

Question 7.
Sketch the cross-section of soil and label the various layers.
Answer:

Fig. A soil profile. Various horizontal zones indicate the stages in soil formation

Question 8.
Razia conducted an experiment in the field related to the rate of percolation. She observed that it took 40 min for 200 mL of water to percolate through the soil sample. Calculate the rate of percolation.
Answer:
Given, amount of water = 200 mL
Time taken = 40 min
Rate of percolation (mL/min) = \(\frac { Amount of water(mL) }{ Amount of water(mL) }\)
= \(\frac { 200 ml}{ 40 Min }\)
= 5 mL / min .

Question 9.
Explain, how soil pollution and soil erosion could be prevented.
Answer:
Prevention of soil pollution:

1. There should be a ban on polythene bags and plastics.
2. Waste products and chemicals should be treated before they are released into the soil.
3. The use of pesticides should be minimized

Prevention of soil erosion:

1. By growing trees.
2. Avoid deforestation.
3. Maintaining the porous structure of the soil.
4. Control and reclamation of ravines and shifting of cultivation.

Question 10.
Solve the following crossword puzzle with the clues given below:

Across
2. Plantation prevents it.
5. Use should be banned to avoid soil pollution.
6. Type of soil used for making pottery.
7. Living organism in the soil.
Down
1. In desert, soil erosion occurs through.
3. Clay and loam are suitable for cereals like.
4. This type of soil can hold very little water.
5. Collective name for layers of soil.
Answer:

We hope the NCERT Solutions for Class 7 Science Chapter 9 Soil help you. If you have any query regarding NCERT Solutions for Class 7 Science Chapter 9 Soil, drop a comment below and we will get back to you at the earliest.

NCERT Solutions for Class 7 Science Chapter 1 Nutrition in Plants are part of NCERT Solutions for Class 7 Science. Here we have given NCERT Solutions for Class 7 Science Chapter 1 Nutrition in Plants.

Board	CBSE
Textbook	NCERT
Class	Class 7
Subject	Science
Chapter	Chapter 1
Chapter Name	Nutrition in Plants
Number of Questions Solved	13
Category	NCERT Solutions

NCERT Solutions for Class 7 Science Chapter 1 Nutrition in Plants

Question 1.
Why do organisms need to take food?
Answer:
Organisms need to take food to

1. get the energy to do work.
2.  build up the body.
3. repair damages in the body.
4.  maintain the functions of the body.

Question 2.
Distinguish between a parasite and a saprotroph.
Answer:

Parasite	Saprotroph
1. A parasite takes the food from the organism on which it survives.	1. They secrete digestive juices on the dead and decaying matter and convert it into a solution
2. They feed on a living organism.	2. They feed on dead and decaying matter.
3. The organism on which it survives is called host.	3. They do not feed on a living organism.
4. It deprives the host of valuable nutrients.	4. There is no host at all.

 Question 3.
How would you test the presence of starch in leaves?
Answer:

1. Take two healthy green potted plants of the same kind in order to remove all the starch from the leaves.
2.  Keep one in the darkroom (or in a black box) for 72 hours and the other in the sunlight.
3.  Now, take one leaf from each of the plants.
4. Put few drops of iodine solution on each of the leaves.
5.  The leaf kept in the sunlight will turn blue-black due to the presence of starch.
6. The leaf kept in the dark will not turn blue-black because of the absence of starch.

Question 4.
Give a brief description of the process of synthesis of food in green plants.
Answer:
The leaves of a plant have a green pigment called chlorophyll. In the presence of sunlight, they use carbon dioxide and water to synthesize carbohydrates.
Carbon dioxide + Water \(\xrightarrow [ Sunlight ]{ Chlorophyll } \) Carbohydrade + Water + Oxygen
During the process, oxygen is released. The carbohydrates ultimately get converted into starch.
Carbon dioxide from the air is taken through stomata. Water and minerals are absorbed by the roots and transported to the leaves.

Question 5.
Show with the help of a sketch that plants are the ultimate source of food.
Answer:

Fig. Plants capture solar energy by a unique process called photosynthesis

Question 6.
Fill in the blanks:

1. Green plants are called …….. since they synthesize their own food.
2. The food synthesized by the plants is stored as ………
3. In photosynthesis solar energy is captured by the pigment called ……….
4. During photosynthesis plants take in ……… and release ……….

Answer:

1. autotrophs
2. starch
3. chlorophyll
4. carbon dioxide, oxygen

Question 7.
Name the following:

1. A parasitic plant with a yellow, slender, and branched stem.
2. A plant that is partially autotrophic.
3. The pores through which leave exchange gases.

Answer:

1. Cuscuta
2. Insectivorous plants
3. Stomata

Question 8.
Tick the correct answer:
(a) Amarbel is an example of:
(i) Autotroph
(ii) Parasite
(iii) Saprotroph
(iv) Host
(b) The plant which traps and feeds on insects is:
(i) Cuscuta
(ii) China rose
(iii) Pitcher plant
(iv) Rose
Answer:
(ii) Parasite
(iii) Pitcher plant

Question 9.
Match the items given in Column I with those in Column II.

Column I	Column II
Chlorophyll	Bacteria
Nitrogen	Heterotrophs
Cuscuta	Pitcher plant
Animals	Leaf
Insects	Parasite

Answer:

Column I	Column II
Chlorophyll	Leaf
Nitrogen	Bacteria
Cuscuta	Parasite
Animals	Heterotrophs
Insects	Pitcher plant

 Question 10.
Mark T if the statement is true and ‘F’ if it is false:
(i) Carbon dioxide is released during photosynthesis. (T/F)
(ii) Plants which synthesize their food are called saprotrophs. (T/F)
(iii) The product of photosynthesis is not a protein. (T/F)
(iv) Solar energy is converted into chemical energy during photosynthesis. (T/F)
Answer:
(i) F
(ii) F
(iii) T
(iv) T

Question 11.
Choose the correct option from the following:
Which part of the plant takes in carbon dioxide from the air for photosynthesis?
(i) Root hair
(ii) Stomata
(iii) Leaf veins
(iv) Petals
Answer:
(ii) Stomata

Question 12.
Choose the correct option from the following:
Plants take carbon dioxide from the atmosphere mainly through their:
(i) roots
(ii) stem
(iii) flowers
(iv) leaves
Answer:
(iv) leaves

Question 13.
Why do farmers grow many fruits and vegetable crops inside large greenhouses? What are the advantages to the farmers?
Answer:
Most of the crops require a lot of nitrogen to make protein. After the harvest, the soil becomes deficient in nitrogen. Though nitrogen gas is available in the air, plants cannot use it directly. They need nitrogen in a soluble form. The bacterium called Rhizobium can take atmospheric nitrogen and convert it into soluble nitrogenous components. Rhizobium is present in the roots of some fruits and vegetables and legumes plants which provides nitrogen to them. By crop rotation, farmers increase the nitrogenous compounds in soil. So there is no need to add nitrogenous fertilizers to the soil in which leguminous plants are grown. By this practice, farmers provide good quality crops and save money.

We hope the NCERT Solutions for Class 7 Science Chapter 1 Nutrition in Plants help you. If you have any query regarding NCERT Solutions for Class 7 Science Chapter 1 Nutrition in Plants, drop a comment below and we will get back to you at the earliest.

NCERT Solutions for Class 7 Science Chapter 8 Winds, Storms and Cyclones are part of NCERT Solutions for Class 7 Science. Here we have given NCERT Solutions for Class 7 Science Chapter 8 Winds, Storms and Cyclones.

Board	CBSE
Textbook	NCERT
Class	Class 7
Subject	Science
Chapter	Chapter 8
Chapter Name	Winds, Storms and Cyclones
Number of Questions Solved	9
Category	NCERT Solutions

NCERT Solutions for Class 7 Science Chapter 8 Winds, Storms and Cyclones

Question 1.
Fill the missing word in the blank spaces in the following statements :

1. The wind is ……… air.
2. Winds are generated due to ……….. heating on the earth.
3. Near the earth’s surface …………. air rises up whereas ………. air comes down.
4. Air moves from a region of ……….. pressure to a region of ……….. pressure.

Answer:

1. moving
2. uneven
3. warm, comparatively cooler
4. high air, low air

Question 2.
Suggest two methods to find out wind direction at a given place.
Answer:
Two methods to find out wind directions are:
(i) using weathercock (Fig.).
(ii) one simple method used by common people is to hold some dust and release in the air. Dust will fly in the direction of air.

Fig. A weathercock

Question 3.
State two experiences that made you think that air exerts pressure (other than those given in the text).
Answer:
Experiment 1: When we fill the air in a balloon it flattens due to pressure exerted by air. Also when it is overfilled with air it bursts due to excess air pressure

Fig. Air exerts pressure
Experiment 2: When we hang a banner in a place of moving fast air, it tears due to the pressure exerted by the air.

Question 4.
You want to buy a house. Would you like to buy a house having windows but no ventilators? Explain your answer.
Answer:
No, a house which has no ventilators is not a safe or healthy house to live in. The air circulation is not present in such a house. So, it has no fresh air. Because warm air rises up and goes out through ventilators and fresh air comes in through windows.

Question 5.
Explain why holes are made in hanging banners and hoardings.
Answer:
We know that air exerts pressure. If there are no holes in the banners and hoardings they will be damaged. To make them safe, holes are made to give the air safe passage.

Question 6.
How will you help your neighbours in case a cyclone approaches your village/ town?
Answer:
I will help by following ways :

1. Warning everyone about the coming danger.
2.  Searching for shelter.
3. Keeping storage of water and food.
4. Setting up a first-aid facility.

Question 7.
What planning is required in advance to deal with the situation created by a cyclone?
Answer:
To deal with the situation created by a cyclone we must do the following planning in advance.
On the part of the government:

• Rapid communication of warnings to the government agencies, the ports, fishermen, ships, and to the general public must be ensured.
• There must be the construction of cyclone shelters in cyclone-prone areas and administrative arrangements for moving people fast to safer places.

On the part of the public following actions must be taken:

• keep ready the phone numbers of all emergency services like police, fire brigade, and medical centres.
• make necessary arrangements to shift the essential household goods, domestic animals and vehicles, etc., to safer places.

Question 8.
Which one of the following places is unlikely to be affected by a cyclone?
(i) Chennai
(ii) Mangaluru (Mangalore)
(iii) Amritsar
(iv) Puri
Answer:
(iii) Amritsar

Question 9.
Which of the statements given below is correct?
(i) In winter the winds flow from the land to the ocean.
(ii) In summer the winds flow from the land towards the ocean.
(iii) A cyclone is formed by a very high-pressure system with very high-speed winds revolving around it.
(iv) The coastline of India is not vulnerable to cyclones.
Answer:
(i) In winter the winds flow from the land to the ocean.

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