NCERT Exemplar Solutions: Conservation of Plants & Animals | Science Class 8 PDF Download

Multiple Choice Questions

Q.1. Wild buffalo is an endangered species because
(a) its population is diminishing
(b) it has become extinct
(c) it is found exclusively in a particular area
(d) its poaching is strictly prohibited
Ans: a
Explanation:
Endangered species are those whose population is decreasing at an alarming rate and they may face extinction in the near future.

Q.2. Which one of the following changes may occur due to desertification?
(a) Increased chances of floods.
(b) Conversion of fertile land into a desert.
(c) The decrease in atmospheric temperature.
(d) Increase in water holding capacity of the soil.
Ans: b
Explanation:
Soil is carried away by the wind when there are no trees as there will be no roots to hold onto the soil. Thus topsoil erodes out which will turn the land to desert.

Q.3. Which one of the following statements is true about a Biosphere Reserve?
(a) It is a protected area where only endemic species live.
(b) It is meant only for the conservation of plants and animals.
(c) It is meant to conserve both the biodiversity and the culture of that area.
(d) There are no other protected areas within its limits.
Ans: c
Explanation:
The biosphere reserve is the protected part of the land covered with forests. It is meant for the conservation of wildlife, biodiversity and traditional lifestyle of tribals.

Q.4. The place meant for the conservation of biodiversity in their natural habitat are
(i) Zoological garden
(ii) Botanical garden
(iii) Wildlife sanctuary
(iv) National park
(a) i & ii;
(b) ii & iii;
(c) iii & iv;
(d) i & iv
Ans: c
Explanation:
In botanical garden and zoological parks species are protected outside their natural habitat and its ex-situ conservation. On the other hand, Wildlife sanctuary and National park are in-situ conservation where conservation of biodiversity occurs in their natural habitat.

Q.5. Which one of the following statements is true about endemic species?
(a) They are found exclusively in a specific habitat.
(b) Endemic species can never become endangered.
(c) They are found only in zoos and botanical gardens.
(d) They are not affected by the destruction of their habitat.
Ans: a
Explanation:
Endemic species are those which are found exclusively in a specific habitat. Endemic species get extinct when habitat is destroyed by human activities or by the introduction of new species is introduced to the habitat.

Q.6. Which of the following feature is correct for a wildlife sanctuary?
(a) It is an artificially created protected area for animals.
(b) It is a protected area for threatened and endangered wild animals.
(c) It is meant for the conservation of only plant species.
(d) Capturing and poaching of animals is strictly prohibited here.
Ans: a
Explanation:
The wildlife sanctuary is an artificially created protected area for animals. Hence option c) is wrong . Wildlife sanctuaries are not specific for threatened and endangered wild animals. Hence answer b) is wrong. Capturing and poaching of animals is strictly prohibited everywhere hence option d) is not appropriate.

Q.7. Which statement is incorrect about endangered species?
(a) Their number has decreased drastically.
(b) They might become extinct in the near future.
(c) They pose a danger to other animals.
(d) Their natural habitat needs to be protected
Ans: c

Q.8. What do blackbuck, elephant, python and golden cat together represent in a forest
(a) fauna
(b) flora
(c) ecosystem
(d) species
Ans: a
Explanation:
Fauna is the animals in a particular area. Flora is the plant species in a particular area. The ecosystem includes the physical environment along with plants and animals of a particular area. A species is a group of inbreeding population.

Q.9. The Red Data Book keeps a record of all the
(i) endemic species.
(ii) extinct species.
(iii) endangered plants
(iv) endangered animals.
(a) i & ii;
(b) ii & iii;
(c) iii & iv;
(d) i & iv
Ans: c
Explanation:
Red Data book keeps a record of endangered animals and endangered plants. Different books are maintained for different species including the plants, animals and other species.

Q.10. Migratory birds fly to faraway areas during a particular time of a year. Which of the following conditions present in their habitat during that time are responsible for this behaviour?
(i) Unavailability of food.
(ii) Extreme weather conditions.
(iii) Overcrowding.
(iv) Lack of nesting areas.
(a) ii & iii;
(b) i & ii;
(c) i & iv;
(d) ii & iv.
Ans: b
Explanation:
Migration of birds is a process of moving to different habitats due to adverse climatic condition. Because of extreme weather conditions, birds fail to gather food and they cannot lay their eggs.

Q.11. In our country, large patches of forests are being cleared for cultivation of crops. The environmental impact of such a practice will lead to
(a) soil erosion
(b) soil conservation
(c) soil pollution
(d) soil fertility
Ans: a
Explanation:
Due to the cutting of trees, there will no roots to hold the soil, because of this topsoil erodes by the action of wind.

Very Short Answer Questions

Q.1. Why is it important to conserve forests?
Ans: Forest should be conserved for balance in nature and to conserve the ecosystem.

Q.2. Mention any one action that you have undertaken to conserve trees
Ans: Donating old books and spreading awareness about deforestation.

Q.3. State whether the following statements are True or False. Correct the false statements.

1. There can be a wildlife sanctuary within a biosphere reserve.
2. Plants of a particular area are collectively termed as fauna.
3. Deforestation leads to an increase in the water holding capacity of the soil.
4. Bison is an endemic fauna of Pachmarhi Biosphere Reserve.

Ans:

1. True.
2. False- Plants of a particular area are collectively termed as flora.
3. False- Deforestation leads to a decrease in the water holding capacity of the soil.
4. True.

Q.4. Can a forest regenerate naturally in a short period of time?
Ans: It takes a long period of time to regenerate the forest naturally.

Q.5. Name the first Reserve Forest of India.
Ans: Satpura National Park.

Short Answer Questions

Q.1. Why are wildlife sanctuaries important for the conservation of plants and animals?
Ans: Wildlife sanctuaries important for the conservation of plants and animals because in these areas poaching or killing animals, and disturbing animals by any means of human activity are prohibited. Moreover, in wildlife sanctuaries animals can live in their natural environment. This promotes their breeding and population increase.

Q.2. Why are endemic organisms in greater danger of becoming extinct?
Ans: Endemic organisms are those which can live in a particular geographical location. Any disturbance to their natural habitat will affect the endemic animals adversely hence they are in great danger of becoming extinct.

Q.3. How are even small animals important in an ecosystem?
Ans: Every organism forms a part of the food chain and ecosystem. Hence every organism is important to balance the ecosystem.

Q.4. A new species X is introduced in a forest. How is it likely to affect the local species of that area?
Ans: Introduction of new species in a forest leads to competition for food and place. Hence it will affect the native species present in the forest.

Q.5. Does soil erosion affect the fertility of soil? How?
Ans: Soil erosion leads to washing out of soil fertile layer of soil. This leads to desertification of land due to lack of fertile soil.

Q.6. What is the unique feature of the biodiversity found in Panchmarhi Biosphere Reserve?
Ans: The biodiversity found in Panchmarhi Biosphere Reserve is similar to that found in upper Himalayan peaks and lower Western Ghats.

Q.7. Mention the aim of Forest (Conservation) Act.

Ans: Aim of the Forest (Conservation) Act are as follows

• To conserve natural forests and the animals present in the forest.
• To meet the basic needs of the people living in the forest.

Q.8. What is biodiversity?
Ans: Biodiversity refers to the variety of plants and animals present in a particular habitat.

Long Answer Questions

Q.1. Is deforestation associated with global warming? Explain.

Ans: Plants absorb Carbon-di-oxide from the atmosphere and release oxygen. Cutting of trees leads to the accumulation of Carbon-di-oxide in the atmosphere. CO2 traps heat rays from the sun which are reflected by the earth. This results in an increase in temperature on earth.

Q.2. How does deforestation lead to frequent floods and droughts?
Ans: Deforestation will reduce the water holding capacity of the soil due to the lack of trees. This reduces infiltration of water into the ground which increases the chances of flood. Cutting of trees leads to the accumulation of Carbon-di-oxide in the atmosphere. CO₂ traps heat rays from the sun which are reflected by the earth. This results in an increase in temperature on earth. Increase in temperature disturbs water cycle which causes draughts and floods.

Q.3. Why should we save paper?
Ans: We should save paper for the flowing reason

1. Trees are cut to manufacture paper. In order to save the trees, the paper should be saved.
2. Saving paper can help in saving water used to manufacture the paper.
3. Usage of the chemical can be reduced which will reduce water pollution.