CHAPTER 15
OUR ENVIRONMENT
LONG ANSWER TYPE QUESTIONS:
1. What are biodegradable and non-biodegradable substances? How do
they affect the environment?
2. Define Ecosystem. What are its components?
3. Briefly mention the role of producers, consumers and decomposers in an
ecosystem.
4. What are trophic levels? Give an example of a food chain and state the
different trophic levels in it.
5. Track a path of energy flow in an ecosystem.
6. Why do food chains generally consist of three or four steps?
7. Why is Ozone layer in the atmosphere important for us? Which
chemicals are responsible for its depletion?
8. How can you help in reducing the problem of waste disposal? Give any
two methods.
9. What are the problems caused by the non-biodegradable wastes that we
generate?
10. What is biological magnification? Will the levels of this magnification be
different at different levels of ecosystem?
SHORT ANSWER TYPE QUESTIONS:
1. Why are some substances biodegradable and some non-biodegradable?
2. Give any two ways in which biodegradable substances would affect the
environment?
3. Give any two ways in which non-biodegradable substances would affect
the environment?
4. What is a food web? Give an example.
5. What will happen if we kill all the organisms in a trophic level?
6. Will the impact of removing all the organisms in a trophic level be
different for different trophic levels? Can the organisms of any trophic
level be removed without causing any damage to the ecosystem?
7. What will happen if decomposers are not there in the environment?
8. What is ozone? How does it affect an ecosystem?
9. Why is damage to the ozone layer a cause for concern? What steps are
being taken to limit this damage?
10. If all the waste we generate is biodegradable, will this have no impact
on the environment?
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VERY SHORT ANSWER TYPE QUESTIONS:
1. Define trophic level.
2. Name the component that makes energy from sunlight available to the
rest of the ecosystem.
3. How much percent of energy of sunlight that falls on green plants is
absorbed by them in a terrestrial ecosystem?
4. In a food chain what percentage of energy is transferred from one
trophic level to the next higher trophic level?
5. What is the role of decomposers in an ecosystem?
6. What is biological magnification or bio-magnification?
7. What is an aquarium?
8. Give one example of ozone depleting substance.
9. Expand the term UNEP.
10.Expand the term CFCs
OBJECTIVE/MULTIPLE CHOICE TYPE QUESTIONS:
1. The term Ecosystem was introduced by:
(a) Miller (b) Haldane
(c ) Tansley (d) Darwin
2. In a food chain, there is:
(a) Bidirectional flow of energy.
(b) Zig zag flow of energy.
(c) Multi directional flow of energy.
(d) Unidirectional flow of energy.
3. Nature’s cleaners are:
(a) Producers
(b) Consumers
(c) Decomposers
(d) Carnivores
4. Which of the following groups contain only biodegradable items?
(a) Grass, flowers and plastic
(b) Grass, wood and plastic
(c) Fruit-peels, cake and lime-juice
(d) Cake, plastic and grass.
5. Which of the following constitute a food chain?
(a) Grass, wheat and mango
(b) Grass, goat and human
(c) Goat, cow and elephant
(d) Grass fish and goat
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6. Which of the following are environment friendly practices?
(a) Carrying cloth-bags to put purchases in, while shopping.
(b) Switching off unnecessary lights and fans.
(c) Walking to school instead of getting your mother to drop you on her
scooter.
(d) All of the above.
7. Which one of the following is an artificial ecosystem?
(a) Pond (b) Crop field
(c) Lake (d) Forest
8. In a food chain, the third trophic level is always occupied by:
(a) Carnivores (b) Herbivores
(c) Decomposers (d) Producers
9. Depletion of ozone is mainly due to:
(a) Chlorofluorocarbon compounds (b) Carbon monoxide
(c) Methane (d) Pesticides
10. Disposable plastic plates should not be used because:
(a) They are made of materials with light weight
(b) They are made of toxic materials
(c) They are made of bio-degradable materials
(d) They are made of non-biodegradable materials
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