NCERT SOLUTIONS FOR CLASS 8 SCIENCE CONSERVATION OF PLANTS AND ANIMALS CHAPTER 7

Question 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 faraway places because of ________ changes.

(a) Wildlife sanctuary
(b) endemic species
(c) climatic

Question 2.
Differentiate between the following.
(a) Wildlife sanctuary and biosphere reserve

Wildlife sanctuary Biosphere reserve
The area reserved in a forest for the protec­tion of wild animals. The area meant for the protection or conservation of the biodiversity. It also helps in maintaining the culture of that area.

(b) Zoo and wildlife sanctuary

Zoo Wildlife sanctuary
A place where animals are protected in an artificial habitat, for an exhibition. A protected area where animals live in their natural habitat.

(c) Endangered and Extinct species

Endangered species Extinct species
The species of animals whose numbers are diminishing to such a level that they might face extinction. The species of animals whose number is zero because of changes in their habitat and other calamities.

(d) Flora and Fauna

Flora Fauna
The plants which are found in a particular area; e.g.Jamun, sal, etc. The animals which are found in a particular area; e.g., leopard, cheetah, elephant, etc.

Question 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

(a) Wild animals: Trees are the habitats as well as sources of food for the wild animals. Deforestation leads to the destruction of the natural habitats of wild animals.

(b) Environment: Deforestation increases the temperature and pollution level of the environment. With the increase in the carbon dioxide level and a decrease in the oxygen level, it gives rise to global warming. It also lowers the level of ground water. Moreover, deforestation decreases the soil fertility and so, increases the chances of natural calamities.

(c) Villages (Rural areas): The decline in rainfall, the decrease in soil fertility, and the chances of natural disaster affect the village life.

(d) Cities (Urban areas): Deforestation result in global warming. It also results in the increase in the level of pollution. Hence, deforestation affects the life in cities.

(e) Earth: Deforestation decreases the fertility of soil. It changes the physical properties of soil. All these changes result in desertification.

(f) The next generation: Deforestation will majorly affect the life of next generation. The next generation will face problems at every step. Climatic conditions will be adversely affected. There will be scarcity of food and clean environment. Next generation won’t be able to see most of the animal species due to habitat loss.

Question 4.
What will happen if

  1. we go on cutting trees
  2. the habitat of an animal is disturbed.
  3. the top layer of soil is exposed.
  1. If we go on cutting trees, then:
    • the temperature will increase to a greater extent.
    • the chances of natural disaster to occur will increase.
    • the water cycle will get disturbed.
  2. If the habitat of an animal is disturbed, then:
    • the animals will lose their natural habitat and will reach the level of being endangered.
    • most of the animals may be forced to invade places meant for human living in search of food and shelter.
  3. If the top layer of soil is exposed, then:
    • the exposed layer will lose all its nutrients, especially the hummus.
    • the water holding capacity of soil will decrease.
    • desertification will take place.

Question 5.
Answer in brief.

  1. Why should we conserve biodiversity?
  2. Protected forests are also not completely safe for wild animals. Why?
  3. Some tribals depend on the jungle. How?
  4. What are the causes and consequences of deforestation?
  5. What is Red Data Book?
  6. What do you understand by the term migration?
  1. The variety in life existing on the earth, their inter-relationships, and their relationships with the environment is referred to as biodiversity. We should conserve biodiversity so as to maintain the food chain. The disturbance in the food chain may affect the whole ecosystem.
  2. Since capturing and killing of animals by poachers is still rampant in protected forests and areas, so they are not safe for wild animals.
  3. Some tribes depend on the jungle for the fulfillment of their basic needs of life, such as food, medicine, clothing, shelter, etc.
  4. The causes of deforestation may be the following:
    • Natural causes like forest fires, droughts, etc.
    • Building factories and houses.
    • Procuring land for cultivation.
    • Making furniture and using wood as fuel.
      The consequences of deforestation are:
    • Natural calamities like floods, etc.
    • Increase in the temperature of the earth, i.e., global warming.
    • Change in the physical properties of soil.
    • A decrease in groundwater level.
    • Extinction of many flora and fauna.
  5. Red Data Book is a sourcebook which keeps records of all endangered plants and animals.
  6. Migration means the movement of a species from its own habitat to some other place during a certain period in a year for breeding or to overcome some climatic conditions.

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.

It’s not justified to cut trees just to fulfill our needs. Trees are known as ‘the lung of the earth’. They are the habitat of many living organisms, including animals. They give us oxygen, and maintain the O2-CO2 balance as well. They firmly bind the soil and hence prevent soil erosion. They also reduce the chances of natural disasters like floods and droughts. They help conserve our rich biodiversity. The cutting of trees causes an increase in the carbon dioxide (CO2) level, which results in global warming. Moreover, it causes soil erosion, floods, the greenhouse effect, etc. Hence, trees must be protected.

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

By taking up the following actions, I can contribute to the maintenance of green wealth of my locality by:

  • Planting saplings and trees.
  • Not throwing the garbage on the streets.
  • Forbidding others to cut trees.
  • Making people aware of the significance of a clean and green environment.
  • Watering the plants regularly and taking proper care of them.
  • Reusing and recycling paper to save trees, energy, and water.

Question 8.
Explain how deforestation leads to reduced rainfall.

Trees give out a huge amount of water in the form of water vapour during transpiration. The reduction of water vapour affects cloud formation and thus, results in less rainfall.

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

Consider the map given below:

NCERT Solutions for Class 8 Science Chapter 7 Conservation of Plants and Animals Q9

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

A large number of trees can be saved by saving paper. This will also save water that is used to manufacture paper. Moreover, the harmful chemicals used in papermaking will show their least effects on human beings and other organisms.
Some ways to save paper are the following:

  • recycling of paper.
  • economical use of paper.
  • paper should not be burnt.

Question 11.
What is meant by deforestation ?

Deforestation means clearing of forests,and using that land for other purpose like building houses and factories.

Question 12.
What is meant by biosphere ?

Biosphere is that part of the earth in which living organisms exist or which supports life.

Question 13.
Define biodiversity.

Biodiversity means the variety and variability of all microorganisms, plant and animal life.

Question 14.
Name two animals that have become extinct.

The mountain quail of Western Himalayas and the pink head duck.

Question 15.
What are Biosphere reserves ?

Biosphere reserves are the areas meant for conservation of microorganisms, plants and animals.

Question 16.
Define species.

Species is a group of individuals which are capable of interbreeding with each other.

Question 17.
What are endemic species ?

Endemic species are exclusively found in a particular area only in small numbers.

Question 18.
What is meant by Wildlife sanctuaries ?

Wildlife sanctuaries are some areas where wild animals are protected and preserved

Question 19.
What are National Parks ?

National parks are reserves that protect the flora and fauna of the place.

Question 20.
Why has the survival of some animals become difficult ?

Survival of some animals has become difficult because of changes in their natural habitat.

Question 21.
What is meant by ecosystem ?

An ecosystem comprises of all the plants, animals and microorganisms in an area along with non-living components such as climate, soil, river, etc.

Question 22.
What is Red Data Book ?

Red Data Book is the source book which keeps a record on population status of the species included in the Red List.

Question 23.
What are migratory birds ?

Birds who cover long distances to reach another land are known as migratory birds.

Question 24.
Name the first Reserve Forest of India.

Satpura National Park.

Question 25.
Name two wildlife sanctuaries of India.

Kangha and Sultanpur.

Question 26.
Kaziranga and Corbett are …………. of India.

National parks.

Question 27.
Name two endangered species of animals.

The bison and antelope are endangered species of animals.

Question 28.
Why should soil be conserved ?

Soil should be conserved to maintain the fertility of the soil.

Question 29.
Name two animal species which have become extinct in the past years..

Dodo and thylacine.

Question 30.
Give one word for species found only in a particular area.

Endemic species.

Question 31.
Name the organisation that produces the Red List.

IUCN (International Union for Conservation of Nature and Natural Resources).

Question 32.
Why do we feel the need for conserving natural resources more than our ancestors did ? Give two reasons.

We have to conserves the natural resources because :

  • the population of the world has increased.
  • as man has progressed his needs have increased.

Question 33.
Differentiate between the following : 

  1. Wildlife sanctuary and Biosphere reserve.
  2. Zoo and Wildlife sanctuary.
  3. Endangered and Extinct species.
  4. Flora and Fauna.
  1. Wildlife sanctuary is a reserve area where wild animals are protected and preserved.
    Biosphere reserves are the areas meant for conservation of biodiversity, i.e., variety of plants, animals and microorganisms. .
  2.  Zoo is a place where animals live in artificial settings for public display. Wildlife sanctuary is a place where animals live in their natural habitat within a protected area.
  3. Endangered species are those whose number are diminishing and are facing extinction. Extinct species are those which are already finished.
  4. Flora are the plants found in a particular area and fauna are the animals found in a particular area.

Question 34.
What is the role of small animals in the ecosystem ?

The role of small animals is important because they form a part of the food chain and food webs.

Question 35.
Name the flora and fauna of Pachmarhi Biosphere Reserve.

Flora – Sal, teak, mango, jamun, silver fern, arjun.
Fauna – Chinkara, blue bull, barking deer, cheetah, leopard, wild dog, wolf.

Question 36.
Name two endemic flora and endemic fauna of Pachmarhi Biosphere Reserve.

Endemic flora – Sal and wild mango
Endemic fauna – Bison, Indian giant squirrels and flying squirrels.

Question 37.
Give two reasons why sanctuaries should be maintained.

  • Sanctuaries are places where killing (poaching) or capturing of any animal is strictly prohibited.
  • Sanctuaries provide protection and suitable living conditions to wild animals.

Question 38.
What are Rock shelters ? Where are they found ?

Rock shelters are found inside the Satpura National Park. These are the prehistoric evidences of human life in these jungles, which give us an idea about the life of primitive humans.

Question 39.
What is Project Tiger ? What is its objective ?

Project Tiger was launched on 1st April 1973 by our government to protect the tigers of the country.

Question 40.
Why should paper be saved ?

We should save paper because it takes 17 full grown trees to make one tonne of paper.

Question 41.
How can we save paper ?

We should reuse used paper and recycle it.

Question 42.
How can the resources be conserved ?

Resources can be conserved by :

  • not wasting the resources.
  • maintaining their quality

Question 43.
Which factors are responsible for cutting of forest ?

As man’s need for land used in housing and farming and wood for fuel and construction increased, he started cutting down forests.

Question 44.
Expand

  • WWF
  • IUCN
  • World Wildlife Fund.
  • International Union for Conservation of Nature and Natural Resources

Question 45.
How can overgrazing destroy forests ?

Due to overgrazing, the young trees get eaten or killed by trampling. The lower leaves are eaten up and the roots and trunks are injured by cattle.

Question 46.
How does vegetation help to conserve water ?

Vegetation slows down the flow of rain water on land and increases the absorption of water by the soil.

Question 47.
Give the difference between Red List and Red Data Book.

The Red List is a compilation of endangered wildlife species. The Red Data Book provides data on population status of the species included in the Red List.

Question 48.

  1. What is Topsoil ?
  2. Mention two ways by which soil erosion can be prevented.
  1. Top soil is the layer of soil contains rock particles, living organisms and humus.
  2. Soil erosion can be prevented by :
    • Contour or step farming, which reduces the flow of water.
    • Planting trees as the roots help to bind the soil.

Question 49.
Mention two steps needed for conserving wildlife. Name two endangered species of animals.

The following steps can be taken to conserve wildlife :

  • by preserving the habitat of wildlife.
  • by making hunting regulations and ensuring their effective implementation.

Bison and Beaver are two endangered species.

Question 50.
“When we conserve forests, we conserve wildlife and soil also”. Discuss.

Wildlife conservation is related to forest conservation. Man has cleared forests, converted grasslands into farmlands and flooded large areas by constructing dams. This has destroyed the habitat of the wildlife. Forests prevent soil erosion and maintain the fertility of the soil.

Question 51.
Explain three ways to conserve forests.

Three ways to conserve forests are : .

  • Planned harvesting — cutting few trees at a time, so that the uncut trees prevent soil erosion and make seeds.
  • Protection from fire.
  • Protection from overgrazing by cattle, sheep, horses, etc.

Question 52.
How can the cutting of trees affect the ecological balance of a particular area?

Cutting of trees :

  • Disturbs the habitat of wild animals, which would lead to extinction of animal.
  • Promotes soil erosion.
  • More floods are caused
  • Disturbs oxygen – carbon dioxide percentage.

Question 53.
Fill in the blanks :

  1. A place where animals are protected in their natural habitat is called …………
  2. Species found only in a particular area is known as ……………
  3. Migratory birds fly to far away places because of ………. changes
  1. Sanctuary
  2. Endemic species
  3. Climatic

Question 54.
What will happen if:

  1.  we go on cutting trees.
  2. the habitat of an animal is disturbed.
  3. the top layer of the soil is exposed.
  1. If we go on cutting trees, rainfall and fertility of the soil will decrease. The chances of natural calamities such as floods and drought will increase. It will lead to decrease in the water holding capacity of the soil and movement of water from the soil surface into the ground. Animal life is also affected by deforestation.
  2. If the habitat of an animal is disturbed, it endangers their existence. Survival of some animals becomes difficult because of the disturbances in their natural habitat.
  3. Removal of the top layer of soil exposes the lower hard and rocky layers. This soil has less humus and it is less fertile. Gradually the fertile land can convert into deserts.

Question 55.
“Water is renewable but oil is not”. Explain.

Water evaporates from forest and other vegetation and condenses in the upper layers of the atmosphere to form clouds and then it rains. The water goes down in the soil and is therefore, a renewable source.
Oil is found below the earth in crude form. It is formed after millions of years. When the oil is used, it is lost. Therefore, it is not a renewable source.

Back