12. Which trophic level has the maximum number of organisms?
a) Producers
b) Primary consumers
c) Secondary consumers
d) Tertiary consumers
Answer: a) Producers
13. Which of the following is biodegradable?
a) Glass bottle
b) Aluminium foil
c) Fruit peel
d) Polythene bag
Answer: c) Fruit peel
14. What happens if decomposers are removed from an ecosystem?
a) Energy flow increases
b) Dead matter accumulates
c) More oxygen is produced
d) Food chains become shorter
Answer: b) Dead matter accumulates
15. Which of these is an environment-friendly practice?
a) Using plastic bags
b) Burning waste
c) Carrying cloth bags
d) Leaving lights on
Answer: c) Carrying cloth bags
True or False
1. Producers are the first trophic level in a food chain. Answer: True
2. Energy flow in an ecosystem is cyclic. Answer: False (It is unidirectional)
3. CFCs help in protecting the ozone layer. Answer: False (They deplete it)
4. All waste generated by humans is biodegradable. Answer: False (e.g., plastics are non-biodegradable)
5. Decomposers convert dead matter into nutrients. Answer: True
6. A food web consists of multiple interconnected food chains. Answer: True
7. Biological magnification benefits top consumers. Answer: False (It harms them due to toxin accumulation)
8. Ozone is harmful at ground level but beneficial in the stratosphere. Answer: True
9. Paper cups are non-biodegradable. Answer: False (They are biodegradable)
10. Only 1% of sunlight energy is captured by plants. Answer: True
11. Aquarium is a natural ecosystem. Answer: False (It is human-made)
12. Herbivores are secondary consumers. Answer: False (They are primary consumers)
13. Plastics decompose quickly in soil. Answer: False (They are non-biodegradable)
14. The ozone hole is caused by excess oxygen. Answer: False (It’s caused by CFCs)
15. Using reusable bags reduces waste. Answer: True
