Important Questions for Exams

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Chapter 15 Class 10 - Our Environment.pdf

 

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Why should the use of plastic and polythene be reduced in daily life?

Answer

Plastic and Polythene are non-biodegradable materials. They cannot be decomposed easily.

They can also not be recycled effectively. So, we should reduce the use of plastic and polythene in daily life

The flow of energy between various components of the environment has been extensively studied. List four findings.

Answer

The findings from Flow of Energy in the environment are

• Flow of energy is unidirectional
• Plants take about 1% of the sun’s energy and change it to chemical energy
• Only 10% of the energy is passed on from one trophic level to the next
• A lot of energy is lost when between one trophic level to another because of heat, digestion, reproduction and to carry out basic life processes
• Food chains are mostly of 3-4 levels because of the 10% law
• The number of producers are maximum, and the number of organisms reduces as we move up the trophic level
• There is Biological Magnification

“Improvements in our lifestyle have resulted in greater amounts of waste generation.” Give two examples to support the given statement. Suggest one change that we can incorporate in our lifestyle in order to reduce nonbiodegradable waste. 

Improvement in our lifestyle has lead to waste generation because

• We are using more disposable items like plastic cups, plastic bottles, polythene bags
• The electronic items are used by everyone these days, which has led to an increase in electronic wastes

Inorder to reduce the non-biodegradable wastes, we can reuse of plastic containers and polythene bags. And we can also replace polythene bags with jute bags or paper bags

The following organisms form a food chain. 

Insect, Hawk, Grass, Snake, Frog 

Which of these will have highest concentration of non-biodegradable chemicals? Name the phenomenon.

Answer

The food chain will look like

So, Hawk is at the top of the food chain. 

And we know that, highest concentration of non-biodegradable materials is at the top of the food chain.

So, Hawk will have the highest concentration of non-biodegradable materials.

This phenomena is called Biological Magnification

“Human beings occupy the top level in any food chain.” What are the consequences of this on our body?

Answer

Due to biological magnification , we know that highest concentration of non-biodegradable and harmful materials is at the top of the food chain.

So, human beings are exposed to high amounts of chemicals and non-biodegradable materials inside their bodies.

This causes diseases