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NCERT solutions Science Textbook for Class 10 chapter 15 Our Environment

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Chapter 15 - Our Environment

Page 257

Why are some substances biodegradable and some non-biodegradable?

Q 1 | Page 257 | view solution

Give any two ways in which biodegradable substances would affect the environment.

Q 2 | Page 257 | view solution

Give any two ways in which non-biodegradable substances would affect the environment.

Q 3 | Page 257 | view solution

Page 261

What are trophic levels? Give an example of a food chain and state the different trophic levels in it.

Q 1 | Page 261 | view solution

List two important roles play in the environment by decomposers.

Q 2 | Page 261 | view solution

Page 264

What is ozone and how does it affect any ecosystem?

Q 1 | Page 264 | view solution

 How can you help in reducing the problem of waste disposal? Give any two methods.

Q 2 | Page 264 | view solution

Pages 264 - 265

Which of the following groups contain only biodegradable items?
(a) Grass, flowers and leather
(b) Grass, wood and plastic
(c) Fruit-peels, cake and lime-juice
(d) Cake, wood and grass

Q 1 | Page 264 | view solution

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

Q 2 | Page 264 | view solution

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

Q 3 | Page 264 | view solution

What will happen if we kill all the organisms in one trophic level?

Q 4 | Page 265 | view solution

 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?

Q 5 | Page 265 | view solution

What is biological magnification? Will the levels of this magnification be different at different levels of the ecosystem?

Q 6 | Page 265 | view solution

What are the problems caused by the non-biodegradable wastes that we generate?

Q 7 | Page 265 | view solution

If all the waste we generate is biodegradable, will this have no impact on the environment?

Q 8 | Page 265 | view solution

Why is damage to the ozone layer a cause for concern? What steps are being taken to limit this damage?

Q 9 | Page 265 | view solution

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