NCERT Class VIII Science Solutions: Chapter 7-Conservation of Plants and Animals Part 4

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Question 21:

Does soil erosion affect the fertility of soil? How?

Answer:

Yes. Soil erosion removes the fertile top layer of the soil thereby, exposing the hard rocky lower layers which are less fertile.

Image of fertility of soil

Image of Fertility of Soil

Image of fertility of soil

Question 22:

What is the unique feature of the biodiversity found in Panchmarhi Biosphere Reserve?

Answer:

The biodiversity found in Panchmarhi Biosphere Reserve is similar to that found in upper Himalayan peaks and lower Western Ghats.

Question 23:

Mention the aim of Forest (Conservation) Act.

Answer:

Conservation of natural forests and meeting the basic needs of the people living in or near the forests

Question 24:

What is biodiversity?

Answer:

Biodiversity refers to the variety of organisms existing in the Earth, their interrelationships and their relationship with the environment.

Image of biodiversity

Image of Biodiversity

Image of biodiversity

LONG ANSWER QUESTIONS

Question 25:

Is deforestation associated with global warming? Explain.

Answer:

Yes. Plants absorb carbon dioxide from the atmosphere for photosynthesis. Deforestation results in decreased number of trees leading to accumulation of carbon dioxide in the atmosphere. Carbon dioxide in the atmosphere traps heat rays reflected by the earth which results in global warming.

Question 26:

How does deforestation lead to frequent floods and droughts?

Answer:

Deforestation results in decreased water holding capacity of soil. This reduces the infiltration of water into the ground which causes floods. On the other hand, deforestation leads to higher level of carbon dioxide in the atmosphere which causes global warming. Scarcity of trees disturbs the water cycle and may reduce rainfall leading to droughts.

Question 27:

Why should we save paper?

Answer:

To prevent deforestation, save energy and water needed for manufacturing the paper. Chemicals used to manufacture the paper also cause pollution.