In this page, we are providing Online Education for Our Environment Class 10 Extra Questions and Answers Science Chapter 15 pdf download. NCERT Extra Questions for Class 10 Science Chapter 15 Our Environment with Answers will help to score more marks in your CBSE Board Exams. https://ncertmcq.com/extra-questions-for-class-10-science/

## Online Education for Class 10 Science Chapter 15 Extra Questions and Answers Our Environment

Extra Questions for Class 10 Science Chapter 15 Our Environment with Answers Solutions

### Extra Questions for Class 10 Science Chapter 15 Very Short Answer Type

Our Environment Class 10 Extra Questions And Answers Question 1.
Give an example each of natural and an artificial ecosystem.
Natural ecosystem : Forest or pond
Artificial ecosystem : Crop field or aquarium.

Extra Questions Of Our Environment Class 10 Question 2.
What is the full form of CFCs and UNEP?
CFC = Chlorofluorocarbons
UNEP = United Nations Environment Programme.

Our Environment Extra Questions Question 3.
Define ecosystem and name its components.
The living and non-living components of an area interact with each other to form an ecosystem. Components of ecosystem are: Biotic (living) and abiotic (non-living)

Class 10 Our Environment Extra Questions Question 4.
What is the role of ozone? Why is it being depleted?
Ozone protects us from harmful UV radiations. It is being depleted due to excess use of chlorofluorocarbons (CFCs).

Our Environment Class 10 Important Questions Question 5.
What is ten per cent law?
Ten per cent law states that only 10% of the energy available at a trophic level is transferred to the next trophic level.

Our Environment Class 10 Extra Questions Question 6.
List two advantage of decomposers to the environment.  [CBSE 2008]

1. They replenish the soil nutrients.
2. They help to clean the environment by degrading the dead remains of plants and animals.

Chapter 15 Science Class 10 Extra Questions Question 7.
What is the ultimate source of energy in an ecosystem? Which process helps to trap this energy in producers?
Sun is the ultimate source of energy in an ecosystem. Photosynthesis helps to trap this energy in producers.

Ch 15 Science Class 10 Extra Questions Question 8.
What is the major cause of ozone depletion? Where are these substances used?  [CBSE 2012]
Chlorofluorocarbons are major cause of ozone depletion. They are used in refrigerator and aerosol sprays.

Class 10 Science Chapter 15 Extra Questions And Answers Question 9.
Biodegradable and non-biodegradable waste should be discarded in two separate dustbins as it will make it easier to recycle the recyclable wastes. This will also save time and energy.

Extra Questions On Our Environment Class 10 Question 10.
What will happen if we kill all the organisms in one trophic level?  [CBSE 2011]
Killing all the organisms in one trophic level would decrease availability of food at the next trophic level and also result in excess of organisms at the previous trophic level. This would cause an imbalance in the food chain.

### Extra Questions for Class 10 Science Chapter 15 Short Answer Type I

Our Environment Class 10 Short Questions And Answers Question 1.
Arrange these organisms in a food chain Snake, Plants, Frog, Bird
Plants → Frog → Snake → Bird

Class 10 Science Chapter 15 Extra Questions Question 2.
Draw an ecological pyramid, depicting the trophic levels.

Extra Questions For Class 10 Science Chapter 15 Our Environment Question 3.
The first trophic level in a food chain is always a green plant. Why?  [CBSE 2015]
Green plants contain a pigment called chlorophyll which traps the energy from the Sun and converts it into chemical energy to be utilised by the members of the next trophic level. So, the first trophic level in a food chain is always a green plant.

Extra Question Of Our Environment Class 10 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]

1. Use of paper bags or jute bags instead of plastic bags.
3. Use fuels like CNG, unleaded petrol or other ecofriendly fuels in vehicles.
Due to uses of environment friendly practices or habits we can save our environment.

Our Environment Extra Questions Class 10 Question 5.
Write the harmful effects of using plastic bags on the environment. Suggest alternatives to plastic bags. [CBSE 2013]
Harmful effects of plastic bags

• They clog the drainage system.
• They choke the alimentary canal of cattle when they get eaten by them.
• On burning they release toxic gases.
• They are non-biodegradable and do not decompose easily.

Alternative to plastic bags:

• Use of jute bags or paper bags.
• Reusable cloth bags.

Extra Questions Of Chapter Our Environment Class 10 Question 6.
Construct an aquatic food chain showing four trophic levels.  [CBSE 2010]
Phytoplankton → Zooplankton → Small fish → Bird.

Biology Class 10 Our Environment Extra Questions Question 7.
Why is improper disposal of waste a curse to the environment?  [NCERT Exemplar]
The improper disposal of wastes pollutes our environment and can cause harm to living organisms.

Class 10 Science Our Environment Extra Questions Question 8.
What are the advantages of cloth bags over plastic bags during shopping?  [NCERT Exemplar]
Cloth bags are better than the plastic bags because they:

• can be used to carry many things
• can be reused
• do not pollute the environment.

Our Environment Class 10 Worksheet With Answers Question 9.
Why are crop fields known as artificial ecosystems?  [NCERT Exemplar]
The crop fields are prepared and maintained by a man so they are man-made ecosystems. Hence, they are also called an artificial ecosystems.

Our Environment Class 10 One Mark Questions Question 10.
We do not clean ponds or lakes, but an aquarium needs to be cleaned. Why? [NCERT Exemplar]
A pond or a lake is a natural, self-sustaining, and complete ecosystem. But, an aquarium is an artificial and incomplete ecosystem that needs human intervention for its cleaning and upkeep.

### Extra Questions for Class 10 Science Chapter 15 Short Answer Type II

Extra Questions For Our Environment Class 10 Question 1.
Differentiate between biodegradable and non-biodegradable substances with the help of one example each. List two changes in habit that people must adapt to dispose non-biodegradable waste for saving the environment.  [CBSE 2015]
1. Biodegradable substances: Substances that can be slowly destroyed and broken down into very small parts by natural processes by bacteria, fungi, etc. For example, organics wastes like vegetables and fruit peels.

2. Non-biodegradable substances: Substances that cannot be broken down or decomposed into the soil by natural agents are called as non-biodegradable. For example, plastic.
Habits to dispose non-biodegradable waste are:

• Segregating and treating the non-biodegradable waste before putting in dustbins.
• Recycle the plastics or glass present in non-biodegradable wastes.
• Motivate people to use paper or jute bags instead of plastic bags.

Our Environment Important Questions Question 2.
Our food grains such as wheat and rice, vegetables and fruits, and even meat are found to contain varying amounts of pesticide residues. State the reason to explain how and why it happens?  [CBSE 2014]
The harmful pesticides like DDT enter the plant body on being absorbed from the soil. When these are eaten by animals they get accumulated in the animal’s body as they are neither metabolized nor excreted out of their body. The concentration of these harmful chemicals gets increased at successive levels and are thus found in food grains as well as meat.

Our Environment Class 10 Questions And Answers Question 3.
How is ozone formed in the higher level of the atmosphere? “Damage to ozone layer is a cause of concern”. Justify this statement.  [CBSE 2010]
Ozone is formed due to action of UV rays on oxygen molecules to form free oxygen atom which subsequently combines with another molecule of oxygen to form ozone. The reaction is:

O + O2 → O3 (Ozone)

Ozone depletion is a cause of concern because it protects us from the harmful ultraviolet radiations of the Sun by absorbing them. The UV rays can cause skin cancer, ageing, cataract, etc. to human beings if they are not absorbed by ozone due to ozone depletion.

Question 4.
Explain phenomenon of “biological magnification”. How does it affect organisms belonging to different trophic levels particularly the tertiary consumers?  [CBSE 2010]
The levels of harmful toxicants/pesticides like DDT gets increased at successive trophic levels as they are neither metabolised nor excreted by the organism. They get accumulated in organism’s body with their higher concentrations at higher trophic levels. This is called as biological magnification.

Since, the tertiary consumers are at the top of the food chain, so a higher amount of these toxicants is present in them compared to the lower trophic levels.

### Extra Questions for Class 10 Science Chapter 15 Long Answer Type

Question 1.
Suggest any four activities in daily life which are eco-friendly.  [NCERT Exemplar]
The eco-friendly activities in life are

• Planting of trees.
• Using cloth bags, jute bags or paper bags instead of plastic bags.
• Creating awareness on environment protection through initiatives and campaigns.
• Using of manures and organic agricultural methods.
• Using less of chemical fertilizers and pesticides.
• Controlling pollution by using fuels like CNG.

Question 2.
Make food chains in (i) forest (ii) grassland (iii) pond. How does food chain differ from a food web?
Food chains in:
(i) Forest: Plants → Deer → Lion
(ii) Grassland: Plants → Grasshopper → Frog → Snake → Eagle
(iii) Pond: Aquatic plants → Scorpion Fish → Flamingo

Food Chain: It is a series of organisms feeding on one another.
Food Web: It is a network of food chains consisting of a number of interlinked food chains.

Question 3.
Indicate the flow of energy in an ecosystem. Why is it unidirectional?  [NCERT Exemplar]
The flow of energy generally is
Sun → Producer → Herbivore → Carnivore

The flow of energy is unidirectional because it goes progressively from one trophic level (lower) to another trophic level (higher) and does not revert back.
It is impossible for energy to flow in the reverse direction as the available energy decreases in the higher trophic levels.

Question 4.
Name the wastes which are generated in your house daily. What measures would you take for their disposal? [NCERT Exemplar]
The wastes generated in our house daily are:

• Kitchen wastes
• Paper wastes like newspapers, bags, envelopes
• Plastic bags
• Vegetable/fruit peels/rinds

The measures which can be taken for their disposal are:

• Dispose of the plastic bags and bottles in a proper way.
• Vegetable/fruit peels can be used to make compost.
• Paper wastes can be used for recycling.
• Prepare a vermicompost pit for the organic wastes from the kitchen.

Question 5.
What are the by-products of fertiliser industries? How do they affect the environment?  [NCERT Exemplar]
The harmful by-products of fertiliser industries are the harmful gases like SO2 and NO. They cause air pollution and combine with the water vapour in the atmosphere to cause harmful acid rain.

Question 6.
Explain some harmful effects of agricultural practices on the environment.  [NCERT Exemplar]

• Change in the chemistry of soil and killing of useful microbes due to excessive use of fertilisers.
• Biological magnification occurs due to excessive use of chemical pesticides.
• Water table gets lowered due to the excess use of ground water.
• Soil fertility is lost due to extensive cropping.
• The natural ecosystems is harmed due to ploughing during agriculture.

### Our Environment HOTS Questions With Answers

Question 1.
“Energy flow in a food chain is unidirectional”. Justify this statement. Explain how the pesticides enter a food chain and subsequently get into our body.  [CBSE 2014]
The flow of energy in an ecosystem occurs from a lower trophic level to the next trophic level i.e., from producers to consumers. It follows the ten percent law and thus cannot return back to producers from consumers. Hence, the flow of energy in a food chain is unidirectional.

The pesticides like DDT enter the food chain after getting absorbed by plants from the soil. Once they enter the food chain, they are neither metabolized nor excreted from the body of the organism. Its concentration increases in the successive trophic level of the food chain.

Question 2.
In a food chain, if 10000 Joules of energy is available to the producer, how much energy will be available to the secondary consumer to transfer it to the tertiary consumer? [CBSE 2012]
(i) Energy available to producers = 10,000 Joules.
Energy transfer to producer = 1% of 10,000 Joules = 100 Joules.

(ii) According to Ten per cent law,
Energy transfer to primary consumer = $$\frac{10}{100}$$ × 100 = 10 Joules.

(iii) Energy transfer to secondary consumer = $$\frac{10}{100}$$ × 10 = 1 Joule

(iv) Energy transfer to tertiary consumer = $$\frac{10}{100}$$ × 1 = 0.1 Joule

### Extra Questions for Class 10 Science Chapter 15 Value Based Questions

Question 1.
Rakshit observed a gardener collecting dry leaves from a garden and burning them. He went to the gardener and advised him to utilise the dry leaves for making manure instead of burning.
(a) Name the two process which can be used to make manures from the dry leaves.
(b) Why did Rakshit advise the gardener not to burn leaves?
(c) What are the values shown by Rakshit?
(d) Why are organic manure better than chemical fertilisers?
(a) Composting and vermicomposting
(b) Burning of leaves emits smoke and harmful gases which pollute the environment.
(c) Environment friendly, concern for life, awareness, scientific attitude, logical thinking, etc.
(d) Organic manures are better than chemical fertilisers as excess use of chemical fertilisers leads to (i) loss in soil fertility (ii) increase in soil salinity.

Question 2.
The students of a school formed an Environment Club and started Campaign to Recycle waste, No cracker campaign and No-plastic campaign.
(а) What are the harmful effects of plastic waste?
(b) What are the alternatives to use of plastic bags?
(c) What are the values exhibited by the students of the school?
(d) Why is it necessary to recycle wastes?
(a) The excess use of plastics causes the following problems:

• It causes environmental pollution.
• Plastic bags are non-biodegradable and can cause problems in the digestive system of animals if they eat these plastic bags.

(b) Alternatives are the use of Jute bags or paper bags.
(c) Values are: Eco-friendliness, Concern for life, Responsible, Creative thinking.
(d) To reduce the amount of garbage generated.

Question 3.
The Government of Delhi has proposed the odd-even formula for the use of cars on an alternate basis. The move is aimed at reducing the level of pollution in the city. Further, this move will also help in the conservation of fuel resources.
(a) Mention the values inherent in such a decision of the Government.
(b) What other options (any two) can be used to reduce the level of pollution in city?
(c) How can such a move help in conservation of fuel resources?
(d) How can we ensure lesser emission of pollutants from the vehicles?