10 BS EM FA 3 KEY 2026

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 10 BS EM FA 3 KEY 2026

SECTION – I (1 Mark Each)

1. Name two abiotic components of an ecosystem.

  • Air

  • Water

2. Which process is represented in the given equation?



  • Formation of ozone

  • Ozone layer formation

3. Expand UNEP.

  • United Nations Environment Programme

4. Man is only a consumer. Justify this statement.

  • Man cannot prepare his own food

  • Depends on plants and animals

5. Write a slogan on environmental protection.

  • Save environment, save future

SECTION – II (2 Marks Each)

6. What would happen if all the producers are removed from an ecosystem?

  • Food chain will break

  • Consumers will die due to lack of food

7. What is Biomagnification?

  • Increase in concentration of harmful substances

  • Occurs at higher trophic levels

  • Seen in food chains

8. What is the role of decomposers in the ecosystem?

  • Break down dead plants and animals

  • Recycle nutrients back to the soil

SECTION – III (4 Marks Each)

9. What steps need to be taken to limit the damage to Ozone layer?

  • Reduce use of CFCs

  • Use eco-friendly refrigerators and ACs

  • Avoid aerosol sprays

  • Follow Montreal Protocol

10. Write differences between biodegradable and non-biodegradable substances.

  • Biodegradable decompose naturally

  • Non-biodegradable do not decompose easily

  • Biodegradable cause less pollution

  • Non-biodegradable cause more pollution

11. Study the table and answer the questions:

a) On whom do primary consumers depend for their food?

  • Producers

b) Snake is an example for which trophic level?

  • Secondary consumer

c) If a tiger feeds on goat, to which trophic level does tiger belong?

  • Secondary consumer

d) Give an example for Autotrophs.

  • Green plants

12. Using disposable paper cups is preferable to using disposable plastic cups. Justify this statement.

  • Paper cups are biodegradable

  • Plastic cups cause pollution

SECTION – IV (8 Marks)

13 (A). Suggest a few environmental friendly practices to reduce waste in your locality.

  • Reduce use of plastic

  • Reuse materials

  • Recycle waste

  • Segregate wet and dry waste

  • Use cloth bags

  • Compost kitchen waste

  • Avoid single-use items

  • Create awareness

(OR)

13 (B). Write differences between producers and consumers.

  • ProducersConsumers
    Prepare their own food
    Depend on others for food
    Are autotrophs
    Are heterotrophs
    Form first trophic level
    Form higher trophic levels
    Example: Green plants
    Example: Animals, humans