NCERT Solutions for CBSE Class 8 Science Chapter 7 – Free PDF Download

Free PDF download of NCERT Solutions Science Class 8 Solutions Chapter 7 – Conservation of Plants and Animals solved by Expert Science Teachers on CoolGyan.Org. All Chapter 7 – Conservation of Plants and Animals Questions with Solutions for NCERT to help you to revise complete Syllabus and Score More marks.
Science Revision Notes for Class 8

NCERT SOLVED

1. Fill in the blanks.

(a) A place where animals are protected in their natural habitat is called _______.
(b) Species found only in a particular area is known as ____________.
(c) Migratory birds fly to faraway places because of ____________ changes.

Ans.  (a) A place where animals are protected in their natural habitat is called wildlife sanctuary.
(b) Species found only in a particular area is known as endemic species.
(c) Migratory birds fly to faraway places because of climatic changes.

2. Differentiate between the following.

(a) Wildlife sanctuary and biosphere reserve
(b) Zoo and wildlife sanctuary
(c) Endangered and extinct species
(d) Flora and fauna

Ans. (a)

(b) 

(c) 

(d)

3. Discuss the effects of deforestation on the following.

(a) Wild animals
(b) Environment
(c) Villages (rural areas)
(d) Cities
(e) Earth
(f) The next generation

Ans. (a)  Wild animals- Animals won’t get their natural habitat and surroundings as well as food. They will start migrating to other habitats. Thus ecosystem is disturbed.

(b)  Environment- Due to deforestation, climatic changes takes place. Global warming is caused due to accumulation of carbon dioxide in the atmosphere. Hence environment gets affected.

(c)  Villages- Villagers cannot grow food because of no rain. So, drought situations will prevail. Villagers will move to towns and cities.

(d)  Cities- Cities flooded with drought-affected villagers, will affect the environment. Food-grains will either not be available or if available, they will be costlier.

(e)  Earth- Deforestation leads to change in soil properties. Physical properties of the soil will get affected badly. The land will be gradually converted into desert. Also, environment of earth will be affected thus making it unsuitable for survival.

(f) The next generation- The coming generation will not be able to see the variations in flora on earth and due to deforestation they will have to face different environmental problems like drought, scarcity of food etc. Thus they are affected.

4. What will happen if.

(a) We go on cutting trees.
(b) The habitat of an animal is disturbed
(c) The top layer of soil is exposed

Ans. (a) If we go on cutting trees, then following situation will arrive:

(i)  The climate change will affect the environment due to global warming and there will be no rain.
(ii)  The soil will become infertile due to regular flooding of top soil.

(b)  If the habitat of an animal is disturbed, the animal may not be in position of getting its natural habitat as well as food.

(c)  Removal of top layer of soil by floods and heavy winds will expose the lower hard and rocky layers. This soil has less humus and less fertility.

5. Answer in brief.

(a) Why should we conserve biodiversity?
(b) Protected forests are also not completely safe for wild animals. Why?
(c) Some tribal depends on jungle. How?
(d) What are the causes and consequences of deforestation?
(e) What is Red Data Book?
(f) What do you understand by the term migration?

Ans. (a) If the biodiversity is not conserved, the life existing on earth, their interrelationships and their relationship with environment will be disturbed.

(b)  It is because despite all these the poachers keep killing or capturing the animals in these forests. That is why protected forests are also not completely safe for animals.

(c)  Some tribals live in the jungle. Jungle provides them food and protection. That is why; they are fully dependent upon the forests.

(d)  Causes of deforestation-

(i) Procuring land for cultivation.
(ii) Building houses and factories.
(iii) Natural Calamities like flood, drought and forest fire.
(iv) Making furniture or using wood as fuel.

Consequence of deforestation-

(i) Global warming.
(ii) Soil erosion
(iii) Melting of ice on poles.
(iv) Lowering of ground water level.

(e) Red Data Book is a source book which keeps a record of all the endangered animals and plants.

(f) Migration is the phenomenon of movement of a species from its own habitat to some other habitat for a particular time period every year due to change of climate and for the purpose of breeding.

6. In order to meet the ever-increasing demand in factories and for shelter, trees are being continually cut. Is it justified to cut trees for such projects?

Ans. Of course, to meet the ever-increasing demand in factories and for shelter, trees are being continually cut, which is not justified at all. If one tree is cut, at least five trees should be grown so that reforestation process will remain continuous. But, if trees are cut blindly and no trees are planted then the earth will face global warming, no rainfall, climate change, soil erosion and deforestation. So, cutting trees for any reason is not justified at all.

7. How can you contribute to the maintenance of green wealth of your locality? Make a list of actions to be taken by you.

Ans. For the maintenance of the green wealth of my locality I will prefer reforestation in the locality. I shall start a campaign, along with my friends, to make the people of locality aware of the importance of trees. Once the people become conscious about the importance of plants they will be requested to do the following-

(a) Each family should plant at least one tree in the monsoon month.
(b) During summer, they should assure watering of the plants everyday.
(c) On the occasion of birthday, marriage ceremony and other happy occasions, they should gift plants to their friends and relatives.

8. Explain how deforestation leads to reduced rainfall.

Ans. Deforestation leads to the accumulation of  in the atmosphere which results in global warming as traps the heat of the sun rays. The increase in temperature of earth will disturb the water cycle and reduce rainfall causing drought in the region.

9. Find out the information about the national parks in your state. Identify and show their location on the outline map of India.

Ans. There is no national park in my native state but near about national park around my locality is

Corbett National Park in nearby state of Uttarakhand.

10. Why should paper be saved? Prepare a list of ways by which you can save paper.

Ans. Manufacturing of paper needs trees. By cutting trees, deforestation is caused. If paper is saved or recycled, so many trees can be saved. To make one tonne of paper 17 full grown trees are to be cut. Therefore, to stop deforestation, we should save paper. It can be saved by recycling. Paper can be recycled for 5-7 times and can be used. If everyone who use paper, could save at least one sheet of paper in a day, we can save many trees in a year.

11. Complete the word puzzle.

Down

1. Species on the verge of extinction.

2. A book carrying information about endangered species.

5. Consequence of deforestation.

Across

1. Species which have vanished.

3. Species found only in particular habitat.

4. Variety of plants, animals and microorganisms found in an area.

Ans.