Class 8 Science Chapter 5 Question Answers - Conservation of Plants and Animals

Q26: Differentiate between wildlife sanctuary and Zoo.

Ans:

Q27: Differentiate between endangered species and extinct species.
Ans: 

Q28: What will happen if the top layer of soil is exposed?

Ans: If the top layer of soil is exposed, then it will gradually expose the lower layer of soil, which is hard and rocky in nature. This type of soil is less fertile as it contains less humus. Continued soil erosion will make the land barren or infertile.

Q29: Why should we conserve biodiversity?

Ans: Biodiversity refers to the number and variety of various life forms like plants, animals microorganisms in an area, plants and animals are interdependent for survival. This means that the destruction of either of the two will automatically effect the survival of other, hence we should conserve our biodiversity to maintain the balance of nature.
Q30: How some tribal depends on the jungle?

Ans: There are some tribal who live in jungle and are totally dependent upon jungle for their food. They gather food, fodders and fallen branches of trees from forest and are dependent upon forest for their daily requirements.

Q32: 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.

Q33: 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.

Q34: 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. 

Q35: 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.

Q36: 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.

Q37: 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.

Q38: 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.

Q39:  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.

Q40: 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.

Q41: 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.