Short Answers - Conservation of Plants and Animals, Science, Class 8 PDF Download

SHORT ANSWER TYPE QUESTIONS
 

Q. 1. What do you mean by deforestation?
Ans. The cutting of trees and forests day by day and using that land for other purposes like urbanisation and the industrialisation is called deforestation.

Q. 2. What are the causes of deforestation?
Ans. Causes of deforestation:
(i) Procuring land for cultivation.
(ii) Building of houses and factories.
(iii) Making furniture or using wood as fuel.
 

Q. 3. How does deforestation cause to decrease rainfall?
Ans. Deforestation would mean that carbon dioxide increases in the atmosphere. It causes global warming as carbon dioxide traps the heat rays reflected by earth. The increase in temperature on earth disturbs the water cycle and reduces rainfall. This could cause droughts.
 

Q. 4. What do you mean by desertification?
Ans. Deforestation changes the physical properties of soil. It causes soil erosion. Removal of top layer of the soil exposes the lower, hard and rocky layers. This soil has less humus and is less fertile. Gradually the fertile land gets converted into deserts. It is called desertification.
 

Q. 5. How does deforestation lead to a decrease in the water holding capacity of the soil?
Ans. Deforestation also leads to a decrease in the water holding capacity of the soil. The movement of water from the soil surface into the ground is reduced. So there are floods. The other properties of the soil like nutrient, content texture also change because of deforestation.
 

Q. 6. What is biodiversity?
Ans. Biosphere is that part of the earth in which living organisms exist or which support life. Biological diversity or biodiversity, refers to the variety of organisms existing on the earth, their interrelationships and their relationship with the environment.
 

Q. 7. What do you mean by Biosphere Reserves?
Ans. The large areas of protected land for conservation of wildlife, plant and animal resources and traditional life of the tribals living in that areas are called biosphere reserves. Pachmarhi Biosphere Reserve is an example of such reserves.
 

Q. 8. How can we protect wildlife?
Ans. Wildlife plays an important role in maintaining balance in the environment. Wildlife can be protected by making special and conserved areas. These areas are restricted for human activities which are against wildlife. Poaching, hunting and cutting of trees are strictly banned. Such areas are called Sanctuaries and National Parks which conserve flora and fauna of earth.
 

Q. 9. What do you mean by endemic species?
Ans. The species of plants and animals, which are found exclusively in a particular area are called endemic species. They are not naturally found anywhere else. A particular type of animal or plant may be endemic to a zone, a state or a country. Sal and wild mango are two examples of the endemic flora of the Pachmarhi Biosphere Reserve. Indian giant squirrel and Bison are endemic fauna of this area.

                                                         Fig. 7.1

Q . 10. What do you mean by species? Explain some detailed features.
Ans. Species are group of population which are capable of interbreeding. This means that the members of a species can reproduce fertile offsprings only with the members of their own species and not with members of other species.
Members of a species have common characteristics.
 

Q . 11. What are wildlife sanctuaries?
Ans. Wildlife sanctuaries are those places which provide protection and suitable living conditions to wild animals. In sanctuaries, killing (Poaching) or capturing of animals is strictly prohibited.
 

Q . 12. What do you mean by a National Park?
Ans. The protected vast areas which conserve animals, plants, landscapes and even the historical objects, are called National Parks. They are very large areas which can protect even whole sets of ecosystems in them. Satpura National Park, Kaziranga National Park are some National Parks in India.
 

Q . 13. Which types of animals are much more in danger of becoming extinct?
Ans. The small animals are much more in danger of becoming extinct than the bigger animals. We kill snakes, frogs, lizards, bats and owls ruthlessly without realising their importance in the ecosystem. They might be small in size but their role in the ecosystem  cannot be ignored. They form a part of food chains and food webs.
 

Q. 14. Explain the term ecosystem.
Ans. The group of all the plants, animals and microorganisms in an area along with non- living components such as climate, soil, river, deltas is called an ecosystem.
 

Q . 15. What do you mean by migration? Write the causes of migration of birds.
Ans. Some species of birds fly to far away areas every year in a particular season. This phenomenon is called migration.

Reasons of Migration:
(i) In search of food
(ii) Due to climatic changes
(iii) For laying eggs
(iv) To enjoy long summer days.
 

Q . 16. How does recycling and saving of papers related to deforestation?
Ans. Trees are used in making papers. About 17 full grown trees are used to make one tonne of paper. So wastage of paper is also a cause of deforestation. Therefore, we should recycle and save the papers. If we save papers, we can save many trees in a year. In this way recycling and saving of papers is directly related to avoid the deforestation.
 

Q . 17. What is the answer for deforestation?
Ans. Reforestation is the answer for deforestation. The reforestation means restocking of the destroyed forests by planting new trees. We should plant as many trees as we cut. If the deforested area is left undisturbed, it re-establishes itself. If we have to retain our green wealth for future generations, plantation of more trees is the only option.
 

Q . 18. What do you mean by Forest Conservation Act?
Ans. In India, we have the Forest Conservation Act. This act is aimed at preservation and conservation of natural forests and meeting the basic needs of the people living in or near the forests.