NCERT Solutions for Class 8 Science Chapter 5 - Conservation of Plants and Animals

NCERT TEXTBOOK QUESTIONS SOLVED
 

Q. 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 far away places because of _____ changes.
Ans. (a) Wildlife sanctuary
(b) Endemic species
(c) Climate.
 

Q. 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) Wildlife sanctuary is the place where wild animals are protected in their natural  habitat. Here poaching or capturing the animals is prohibited.
Biosphere reserves are the area used to conserve biodiversity like plants, animals and microorganisms. It contains many wildlife sanctuaries and national parks.
(b) Zoos are the places where some animals are protected in artificial habitats for public view.
Wildlife sanctuaries are used to protect and conserve wildlife in their natural habitats.
(c) The species which are at the verge of extinction and required protection and conservation are called endangered species.
The species which exist no more on the earth are called extinct species.
(d) The word flora is used to refer to varieties of plants while fauna is used to refer to all the varieties of animals.
 

Q. 3. Discuss the effects of deforestation on the following:
(a) Wild animals
(b) Environment
(c) Villages (Rural areas)
(d) Cities (Urban areas)
(e) Earth
(f) The next generation.
Ans. (a) Wild animals: Deforestation destroys the habitats of many wild animals. They are left to die without their natural shelter.

(b) Environment: Deforestation affect the environment adversely due to disturbance of ecological balance. The amount of carbon dioxide is increased in the atmosphere and causes global warming and pollution.

(c) Villages (Rural areas): The villagers depend on forests. They are closely related to forests. Due to deforestation various wild animals run to nearby villages and cause danger to them. Villagers will not get fruits, fuel, wood due to deforestation and rainfall will also decrease.

(d) Cities (Urban areas): Deforestation does not affect the life of cities directly but changes in climate affect cities.
Calamities like flood and droughts do not spare cities.

(e) Earth: Deforestation affects the earth. The fertile land of earth is converted into deserts and its temperature rises. The ground water level also gets lowered. It changes its climate and environment.

(f) The next generation: Many beautiful fauna and flora are destroyed due to deforestation. So, next generation will not be able to see them. They will not get clean and cool environment. They will not have healthy environment.
 

Q. 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:
(i) Ecological balance is disturbed.
(ii) Earth will loose top fertile layer and will be converted into desert.
(iii) Floods and droughts will become more frequent.
(iv) Many animals lost their shelters.
(v) There will be a scarcity of things like fruits, paper which we get from forests.

(b) Animal becomes unprotected and unconserved when its habitat is disturbed. It becomes endangered.

(c) Top layers of soil are fertile. If they are exposed, they lose their fertility and humus. It causes desertification.
 

Q. 5. Answer in brief:
(a) Why should we conserve biodiversity?
(b) Protected forests are also not completely safe for wild animals. Why?
(c) Some tribals depend on the 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) Biodiversity is conserved to save them from extinction.
(b) The protected forests are also not safe completely for wildlife because the poaching takes place at large scale in these areas. The poachers kill wild animals in these protected areas.
(c) Some tribals depend on the jungle for their food, cloths, shelter and other requirements.
(d) Deforestation is caused due to urbanisation and industrialisation.Deforestation is responsible for desertification and natural calamities. Many species of plants and animals are destroyed due to deforestation.
(e) Red Data Book is the record book and source book of all the endangered animals and plants.
( f ) Periodical movement of a species of birds from their native place to other places due to changes in climate is called migration. The purpose of migration is for breeding and to enjoy long summer days.
 

Q. 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? Discuss and prepare a brief report.
Ans. The continuous cutting of trees is not justified for any project. We not only cut the trees, we snatch away the shelters of many animals, birds and other organisms. The ecological balance is also disturbed. It also causes many natural calamities.
 

Q. 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. (i) We can grow more and more plants in our locality.
(ii) We can protect them and provide water to them.
(iii) All the residents should be taught about the benefits of trees.
(iv) They should also be taught about the harms of cutting trees.
 

Q. 8. Explain how deforestation leads to reduced rainfall.
Ans. Plants are the main agent to maintain the water cycle in the environment. So cutting of trees reduces the rainfall of that area. If plants will not absorb water from soil they will not evaporate in the environment to form clouds. If clouds will not be formed  then no rainfall takes place. In this way, deforestation reduces rainfall.
 

Q . 9. Why should paper be saved? Prepare a list of ways by which you can save paper.
Ans. The wood pulps and the bark of trees are used in the manufacturing of paper. If paper is not saved it causes cutting more and more trees. So we should save paper to protect our trees.
Ways to Save Paper: (i) Paper should be recycled.
(ii) We should not throw paper here and there.
(iii) Waste paper should be collected and sent for recycling.