Class 8 Science NCERT Solutions for Chapter – 7 Conservation of Plants and Animals

Conservation of Plants and Animals

Question 1.
Fill in the blanks :

(a) A place where animals are protected in their natural habitat is called ________.
Answer:
Wildlife sanctuary

(b) Species found only in a particular area is known as ________.
Answer:
Endemic species

(c) Migratory birds fly to faraway places because of ________ changes.
Answer:
Climatic

Question 2.
Differentiate between the following :

(a) Wildlife sanctuary and biosphere reserve.
Answer:

Wildlife SanctuaryBiosphere Reserve
This is an area where wild animals are protected and preserved.A biosphere reserve is a large area of protected land for conservation of wildlife, plant and animal resources, and traditional life of the tribals living in the area
The Wildlife sanctuary is a place found in isolation or in biosphere reservesA biosphere reserve may also contain other protected areas like wild­life sanctuary.
Bori and Panch- machi are two wildlife sanctuaries in the Panels machi biosphere. Panchmarhi, for example, is a biosphere reserve.

(b) Zoo and wildlife sanctuary.
Answer:

ZooWildlife Sanctuary
It is a place where we protect animals.Here, too, wild animals are protected and conserved.
Here artificial surroundings are made for animals in place of natural habitats.They live in their natural habitats.
Here animals are supplied prepared food.They get their food from forests (sanctuaries) themselves.

(c) Endangered and extinct species.
Answer:

Endangered SpeciesExtinct Species
These are those species that are facing the danger of extinction.They are the species that have already been banished from the earth.
Tiger is an example of an endangered species.Dinosaur is an example of extinct species.

(d) Flora and fauna.
Answer:

FloraFauna
Flora is the plants found in a particular regionFauna is the animals found in a particular region.
Sal, teak, mango, Jamun, silver ferns, Arjun, etc. are examples, of flora.Chinkara, blue bull, barking deer, cheetah, leopard, wild dog, and wolf are examples of fauna.

Question 3.
Discuss the effects of deforestation on the following :

(a) Wild animals

Answer:
They won’t get their natural habitat and surroundings, as well as food. So either they will extinct or reach the verge of extinction or they will migrate to another forest. In course of their migration, they might be killed by humans.

(b) Environment

Answer:
Climatic changes disturb the environment. Global warming is caused due to accumulation of carbon dioxide. Because of deforestation and an increase in the temperature on earth, the water cycle will get disturbed and the reduced rainfall will cause droughts.

(c) Villages (rural area)

Answer:
Villagers cannot grow food (crops) because of no rain as drought situations will prevail. Many poor villagers may die for want of food. The villagers will move to towns and cities. On one hand, villages will be completely deserted and on the other hand, the towns and cities will be overcrowded.

(d) Cities (urban area)

Answer:
Cities flooded with drought-affected villagers will disturb the environment. Food-grains will either not available or if available, they will be costlier. People will also not get wood for making furniture and buildings.

(e) Earth

Answer:
Deforestation is a major cause, which leads to change in the soil properties. Gradually the land will get converted into a desert. On the other hand, the snow of the mountains will melt due to global warming, and many coastal cities will be flooded causing disaster.

(f) The next generation

Answer:
The next generation will either be extinct or if at all it exists, it will suffer from diseases and face life scarcity of food in life. So, the next generation will be ill, weak, and, consequently, face extinction.

Question 4.
What will happen, if :

(a) we go on cutting trees.

Answer:
If we go on cutting trees, then the following situation will arrive :

  1. The climatic change will affect the environment due to global warming.
  2. The soil will become infertile due to regular flooding of topsoil. Consequently, the land will become a desert.

(b) the habitat of an animal is disturbed.

Answer:
If the habitat of an animal is disturbed, the animal may not be in a position of getting its natural habitat as well as food. So, in the t long run, the animal will face extinction.

(c) the top layer of soil is exposed.

Answer:
Removal of the 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. So, gradually the fertile land will be converted into a desert.

Question 5.
Answer in brief :

(a) Why should we conserve biodiversity?

Answer:
We should conserve biodiversity so that the life existing on earth, their interrelationships, and their relationships with the environment would not get disturbed.

(b) Protected forests are also not completely safe for wild animals. Why?

Answer:
It is because, despite all efforts, poachers keep killing or capturing the animals in these forests. That is why protected forests are also not completely safe for wild animals.

(c) Some tribals depend on the jungle. How?

Answer:
Some tribals live in the jungle. The Jungle provides them food, the raw material for constructing their shelters, and raw materials to make things to earn their livelihood. That is why they are fully dependent on the forest.

(d) What are the causes and consequences of deforestation?

Answer:
Causes of deforestation :

  1. Procuring land for cultivation.
  2. Building houses and factories.
  3. Making furniture or using wood as fuel.
  4. Some natural causes like forest fires and severe droughts.

The followings are the consequences of deforestation :

  1. Global warming disturbs the water cycle and reduces rainfall. Ultimately, drought is caused.
  2. Soil erosion and desertification of land.
  3. Melting of snow on the poles, which causes flooding of seas and oceans causing submerging of land by the sides of seas and oceans.

(e) What is Red Data Book?

Answer:
Red Data Book is the sourcebook that keeps a record of all endangered animals and plants.

(f) What do you understand by the term migration?

Answer:
Migration is the phenomenon of the movement of a species from its own habitat to some other habitat for a particular time period every year because of changing a climate or for the purpose of breeding.

Question 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.

Answer:
Of course, to meet the ever-increasing demand in factories and for shelter, trees are being continually cut, which is hot justified at all. If one tree is cut, at least five trees should be grown so that the reforestation process may remain continuous.

But, if trees are cut blindly and no trees are planted then the earth may face global warming, no rainfall, climatic change, soil erosion, and desertification, etc. So, cutting trees for any reason at all is not justified.

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

Answer:
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 the locality aware of the importance of trees/plants. Once people become conscious of the importance of plants, they will be requested to do the following:

(1) Every member of each family should plant at least one tree in the monsoon month and take care of them.

(2) During summer, they should assure the watering of the plants every day.

(3) On the occasion of birthdays, marriage ceremony and other happy occasions, they should gift their friends and relatives a plant in place of costly gifts.

(4) On national holidays, a seminar should be arranged to discuss subjects like the importance of plants, environment restoration, biodiversity, etc.

Question 8.
Explain how deforestation leads to reduced rainfall?

Answer:
Deforestation leads to the accumulation of CO2 in the atmosphere which results in global warming as CO2 traps the heat of the sunrays. The increase in temperature on earth will disturb the water cycle and reduce rainfall, causing drought in the region.

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

Answer:
I am a resident of Delhi. There is no national park in this state. However, three national parks Ranthambhor, Bharatpur, and Sariska are located in Rajasthan, which is close to Delhi. These are shown in the map given below.
NCERT Solutions for Class 8 Science img 11

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

Answer:
Manufacturing of paper needs trees. By cutting trees, deforestation is caused which disturbs the balance in nature. If a paper is saved or recycled, many trees can be saved. Paper can be saved by recycling.

Paper can be recycled for .5-7 times and can be used. If everyone who uses paper, could save at least one sheet of paper in a day, we can save many trees in a year.

We should save and reuse the used paper and recycle it. By following these steps we can save not only the trees but also the energy and water needed for manufacturing paper.

Question 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 that have vanished.
3. Species found only in a particular habitat.
4. Variety of plants, animals, and microorganisms found in an area.

Answer:
NCERT Solutions for Class 8 Science img 10

InText Questions and Answers

Question 1.
What is the purpose of making national parks, wildlife sanctuaries, and biosphere reserves?

Answer:
The purpose of making national parks, wildlife sanctuaries, and biosphere reserves is to conserve and preserve forests and wild animals.

7.1 Deforestation and its Causes

Activity 7.1

Question 1.
Add more causes of deforestation to you. list and classify them into natural and man-made.

Answer:
Apart from the causes given in the book of deforestation, other causes are as follows :

  1. Cutting plants and trees for different purposes – Man-made cause.
  2. Setting fires in the forest to clear the area – Man-made cause
  3. Flood – Natural cause

7.2 Consequences of Deforestation

Question 2.
How does deforestation reduce rainfall on the one hand and lead to floods on the other?

Answer:
Deforestation reduces rainfall, as :

  1. It leads to global warming, which disturbs the water cycle.
  2. Cooling of the environment by transpira¬tion is lacked due to deforestation.

Deforestation leads to flood, as :

  1. Trees help in lapping down water to recharge groundwater.
  2. Roots of trees hold soil and do not allow erosion.

Question 3.
We have studied in class VII that we get many products from the forests. List these products. Will we face a shortage of these products if we continue cutting trees?

Answer:
The products we get from the forest are :

  1. Different kinds of fruits.
  2. Various types of medicinal and herbal plants and trees.
  3. Wood for making furniture.
  4. Wood for constructing houses.
  5. Grasses to construct thatched houses.
  6. Honey.

If we go on Cutting the trees of those forests, it will lead to their destruction and we will not only face the shortage of these products but the natural calamities also arise due to deforestation.

Activity 7.2

Question 1.
Animal life is also affected by deforestation. How? List the points and discuss them in your class.

Answer:
The trees and grasses are the shelters of animals and birds. If deforestation continues, wildlife will be affected adversely. Wild animals may die because they won’t get their food and shelter in that situation.

7.3 Conservation of Forest and Wildlife

Question 4.
Having become aware of the effects of deforestation, Paheli, and Boojho are worried. They go to Prof. Ahmad and ask him how forests and wildlife can be saved.

Answer:
The forests and wildlife can be saved by reforestation and to conserve wildlife in their natural habitat having many national parks, wildlife sanctuaries, and biosphere reserves.

Activity 7.3

Question 1.
Find out the number of national parks, wildlife sanctuaries, and biosphere reserves in your district, state, and country. Record in Table 7.1 (Textbook, P. 79). Show these areas in an outline map of your state and India.

Answer:
I am a resident of Delhi. In Delhi, though there is a zoo there is no national park, wildlife sanctuary, or biosphere reserve.

Protected areaNational parkWildlife sanctuaryBiosphere reserve
In my district000
In my state000
In my country7542814
NCERT Solutions for Class 8 Science img 12

7.4 Biosphere Reserve Activity 7.4

Question 1.
List the factors disturbing the biodiversity of your area. Some of these factors and human activities may disturb the biodiversity unknowingly. List these human activities. How can these be checked?

Answer:
Biodiversity refers to the variety of living organisms existing on the earth. The biodiversity of an area can be disturbed by the following activities :

  1. Killing or hunting animals for different purposes.
  2. Cutting trees and grasses which have medicinal importance.
  3. Setting fire in the forest for making, areas for agricultural purposes.
  4. Burning forests for human habitations.
  5. Making roads to pass to another side through a forest.
  6. These are some of the human activities because of which biodiversity gets disturbed.

These steps should be followed so that biodiversity may not get disturbed :

  1. Killing or hunting animals should be banned completely.
  2. Fires should not be set on in forests.
  3. Forests should not be cleared.
  4. More and more forests should be converted into Wildlife Sanctuaries, National Parks, or Biosphere Reserves.

7.5 Flora and Fauna

Activity 7.5

Question 1.
Try to identify the flora and fauna of your area and list them.

Answer:

  • Flora (trees and plants): Ferns, Jamun, mango, sal, teak, Arjun, pipal, Kadam, Kelkar, babool, etc., are some of the flora present in bur locality.
  • Fauna: Wild dog, leopard, wolf, deer, chital, chinkara, blue bull, barking deer, etc., are some of the fauna present in our Ideality.

7.6 Endemic Species

Question 5.
I have heard that some of the endemic species may vanish. Is it true?

Answer:
Yes, some of the endemic species may vanish, if their poaching is not stopped, or they are not looked after well or their original area is changed.

Activity 7.6

Question 1.
Find out the endemic plants and animals of the regions where you live.

Answer:

  • Endemic plants: Sal, wild mango, Jamun, and mahua.
  • Endemic animals: Indian giant squirrel and bison.

7.7 Wildlife Sanctuary

Question 6.
What is the difference between a zoo and a wildlife sanctuary?

Answer:
In both zoo and wildlife sanctuary, wild animals are conserved. In wildlife sanctuary, the animals get their natural habitat and naturally available food. On the other hand, in a zoo, these animals are provided artificial habitat. The food is also provided artificially.

The animals living in the zoo are looked after by animal-doctors, in case they fall sick, which is not possible in the forest. In spite of being given a lot of artificial facilities, the animals do not remain hale and hearty, whereas in their natural habitat they are free, hale, and hearty.

Activity 7.7

Question 1.
Visit a nearby zoo. Observe the conditions provided to the animals. Were they suitable for animals? Can animals live in an artificial setting instead of their natural habitat? In your opinion,- will the animals be comfortable in a zoo or in their natural habitat?

Answer:
In the zoo, the tall trees and bushes are grown abundantly. There are a lot of ponds, water reserves, and artificial lakes made here and there. Fruit trees are also grown in plenty. To some extent, these facilities are suitable but not sufficient.

During winter, animals are provided with heaters to provide the heat. And during summer, an arrangement of coolers is made to make wild animal’s life comfortable.

But, I believe, these are not appropriate, because wild animals would like to live in the forest happily and not in these artificial settings. Wild animals will be far more comfortable in their natural habitat than in a zoo.

7.8 National Park

Question 7.
Are tigers still found in the forest?

Answer:
Yes, tigers are still found in the forest, but their numbers are declining day by day due to poaching for their skin and teeth. Tiger is now declared as an endangered species.

7.10 Migration

Question 8.
What would happen if we had no wood? Is there any alternative available to wood?

Answer:
If there were no wood, we would not have got any paper, fruits, or herbal medicines at all. But, there is an alternative for saving wood and have paper as well. The used paper could be recycled 5-7 times and can be used. If a student saves at least one sheet of paper in a day, he/she can thus save many trees in a year.

7.11 Recycling of Paper

Question 9.
Is there any permanent solution to the problem of deforestation?

Answer:
Yes, there is a permanent solution for the problem of deforestation which is reforestation, i.e., restocking of the destroyed forests by planting new trees.