Class 8 Science Chapter - 7 Conservation of Plants & Animals Notes, Previous Year Questions & NCERT Solutions

Class 8 Science

Chapter - 7

Conservation of Plants & Animals

Notes, Previous Year Questions & NCERT Solutions 

                                                 --Notes--

Biosphere: Part of Earth that supports life is called biosphere. Here all living organisms exist.

Biodiversity: Variety of organisms that exist on Earth, their inter-relationships, & their relationship with their environment is called Biological Diversity or Biodiversity.

Wildlife Sanctuary: This is a protected area where animals can live in their natural habitat without any disturbance.

National Park: This area is reserved for wildlife allowing them to freely use the available habitats and natural resources.

Biosphere Reserve: Biosphere reserves are larger areas of land which aim to conserve the wildlife as well as the traditional life of the tribal living in the area (allowing them to use the plant and animal resources to some extent).

Deforestation and Its Causes

• Deforestation means clearing of forests for different purposes, such as timber and other uses of land.
• Major reasons for deforestation are:-

1. Forest fires & severe droughts also lead to deforestation.
2. Using wood as fuel, to make furniture, and for industrial purposes
3. Using the land for building houses and factories
4. Clearing woods to procure land for cultivation & grow more food for increasing population

Consequences of Deforestation

Why would deforestation lead to an increase of carbon dioxide in the atmosphere and global warming?

Plants use carbon dioxide for photosynthesis and release oxygen maintaining the atmospheric balance. Fewer trees means that less carbon dioxide will get recycled in this manner.

Carbon dioxide traps heat rays reflected by the Earth which increases in temperature on the Earth and leads to global warming.

How does deforestation cause droughts and reduction in rainfall?

When trees are cut down, the percentage of carbon dioxide in the atmosphere increases which causes global warming. Moreover, plants absorb water from the soil and release it in the air through transpiration. It is this moisture in the air which eventually turns into clouds and returns to Earth as rainfall.

Deforestation and increase in temperature on the Earth disturb the water cycle, which leads to a reduction in rainfall and droughts.

What is desertification and how is it caused?

Desertification is the process by which a fertile land turns into a desert. Deforestation is a major cause of desertification as it exposes the top layer of soil to natural forces like wind, water and sunlight. With no roots to hold the soil, it gets eroded quickly and the lower, hard and rocky layers of the soil get exposed. These layers have less humus and are less fertile. Gradually, fertile lands turn into deserts.

How does deforestation affect the quality of soil?

The forests add humus to the top layer of the soil. Their roots hold the soil together and allow the surface water to seep into the soil. Due to desertification:

• the soil erosion takes place,

• physical properties of the soil change and it becomes less fertile (its nutrient content and texture changes), and

• the water holding capacity of the soil decreases which may lead to floods.

Conservation of Forest and Wildlife

What is wildlife conservation?

Wildlife Conservation is the practice of protecting endangered plant animal species and their habitats in an effort to maintain the ecological balance.

How does the government conserve our forests and wildlife?

The government lays down rules, regulations and policies to protect our forests and wildlife. Besides, it also earmarks rich flora and fauna habitats as protected areas where the following activities are prohibited:

• Cutting down trees

• Grazing cattle

• Hunting

• Plantation and cultivation

• Poaching (illegally killing or capturing wild animals)

Biosphere Reserve

A Biosphere Reserve is an area which aims to conserve the biodiversity of the area as well as its culture. It may contain other protected areas within it. For Example, Panchmarhi Biosphere Reserve has a national park called the Satpura National Park and two wildlife sanctuaries called the Bori Wildlife Sanctuary and the Panchmarhi Wildlife Sanctuary.

Biosphere Reserves in India

There are 18 biosphere reserves in India, which are:

S. No.	Name	State
10	Achanakmar-Amarkantak Biosphere Reserve	Madhya Pradesh, Chhattisgarh
14	Agasthyamalai Biosphere Reserve	Kerala, Tamil Nadu
12	Cold Desert	Himachal Pradesh
16	Dibru-Saikhowa	Assam
8	Dihang-Dibang	Arunachal Pradesh
15	Great Nicobar	Andaman and Nicobar Islands
11	Great Rann of Kutch	Gujarat
3	Gulf of Mannar	Tamil Nadu
13	Khangchendzonga	Sikkim
6	Manas	Assam
2	Nanda Devi Biosphere Reserve	Uttarakhand
1	Nilgiri Biosphere Reserve	Tamil Nadu, Kerala and Karnataka
4	Nokrek	Meghalaya
9	Panchmarhi Biosphere Reserve	Madhya Pradesh
18	Panna	Madhya Pradesh
17	Seshachalam Hills	Andhra Pradesh
7	Simlipal	Odisha
5	Sundarbans	West Bengal

Flora and Fauna

Flora: Plants found in a particular area are referred to as the flora of the area.

For Example, flora in the Panchmarhi Biosphere Reserve includes:

Sal	Arjun
Teak	Silver Fern
Mango	Jamun

Fauna: Animals found in a particular area are referred to as the fauna of the area.

For Example, fauna in the Panchmarhi Biosphere Reserve includes:

Blue-bull	Wolf
Leopard	Barking Deer
Cheetal	Chinkara

Endemic Species

Species: A group of living organisms that can interbreed with each other are called a Species. It means that only members of one species can reproduce offspring that are fertile and can give birth to future generations. Members of a species look like each other and share many characteristics.

Endangered Species: Species whose number diminish so much that they might face extinction (or vanish off the face of the Earth) are known as Endangered Species. There can be endangered animals as endangered plants.

Endemic Species: Species of plants and animals that are exclusively found in a particular area are called Endemic to that zone, state or country. The endemic species are not found anywhere else naturally.

For Example:

Endemic flora of the Panchmarhi Biosphere Reserve includes sal and wild mango.

Sal	Wild Mango

Endemic fauna of the Panchmarhi Biosphere Reserve includes bison, Indian giant squirrel and flying squirrel.

Bison	Wild Mango
Flying Squirrel

Wildlife Sanctuary

Wildlife Sanctuaries are reserved forests where wild animals are protected and provided with suitable living conditions. Unlike a zoo, animals in wildlife sanctuaries live in their natural habitat and are free to roam anywhere as they like.

People living in Wildlife Sanctuaries can:

• Graze livestock, and

• Collect firewood or medicinal plants.

Activities prohibited in wildlife sanctuaries include:

• Killing (poaching) animals

• Capturing animals

These activities in wildlife sanctuaries are punishable by law.

Wildlife Sanctuaries in India

Indian wildlife sanctuaries have unique landscapes which include broad-level forests, mountain forests, and bushlands in deltas of big rivers. They protect several threatened wildlife species such as golden cat, pink-headed duck, black buck, white-eyed buck, gharial, marsh crocodile, elephant, rhinoceros, python etc.

Unfortunately, people encroach upon the land of these protected forest areas and destroy them.

There are 543 wildlife sanctuaries in India, which include as many as 50 tiger reserves which focus on the conservation of the tiger. The tiger reserves work under Project Tiger. Jim Corbett was the first tiger reserve of India. It is situated in Uttarakhand and is also the oldest national park in India.

Project Tiger is a government initiative to protect tigers. Its objective was to ensure the survival and maintenance of the population of tigers in India.

Similarly, some of these wildlife sanctuaries are called bird sanctuaries as they focus on protecting birds. Keoladeo National Park, was a bird sanctuary before it attained the National Park status.

Some national parks focus on conserving a particular species, Eg.- Jawai leopard sanctuary which is in Rajasthan.

National Park

National Parks are large forest reserves that attempt to preserve the entire ecosystems within the area including the landscape, flora, fauna, and historic objects of the area.

Satpura National Park is the first Reserve Forest of India. Within this forest, you can find the finest Indian teak as well as rock shelters which are evidence of the prehistoric human life in the area.

There are a total of 55 rock shelters in Pachmarhi Biosphere Reserve which also feature rock paintings depicting figures of men fighting with animals, hunting scenes, dancing, and playing musical instruments. Many tribal are still living in the area.

National Parks in India

There are 104 national parks in India. Top 10 of these national parks include:

• Jim Corbett National Park, Uttarakhand

• Kaziranga National Park, Assam

• Gir Forest National Park, Gujarat

• Sundarban National Park, West Bengal

• Satpura National Park, Madhya Pradesh

• Eravikulam National Park, Kerala

• Pench National Park, Madhya Pradesh

• Sariska National Park, Rajasthan

• Kanha National Park, Madhya Pradesh

• Ranthambore National Park, Rajasthan

Why do animals become extinct?

Disturbances in the natural habitat of animals make it difficult for them to survive and hence, become extinct. Ex.- dinosaurs became extinct thousands of years ago.

Why do we need to conserve animals?

Animals, such as lizards, snakes, owls, and bats, play a particular role in an ecosystem and help in maintaining its balance. They form part of food chains and food webs. We need to conserve different life forms to make sure that the natural balance does not get disturbed.

What do we mean by an ecosystem?

An ecosystem refers to the living organisms and non-living components of a place, including plants, animals, microorganisms, climate, soil, river deltas etc.

Red Data Book

International Union for Conservation of Nature (IUCN) maintains a record of all the endangered animals and plants in the world and calls it Red Data Book. India also maintains its own Red Data Book which keeps a record of endangered plants and animals found in India.

The Golden Toad now makes the Extinct as well as the Extinct in the Wild lists of the IUCN Red List.

There is a Red Data List too, which is also known as IUCN Red List of Threatened Species or IUCN Red List which classified all known plant and animal species into nine groups:

• Extinct: No known individual of the species is alive.

• Extinct in the Wild: No known individual of the species in the wilderness. They exist only in captivity.

• Critically Endangered: Species that are at extremely high risk of being extinct in the wilderness.

• Endangered: Species that are at high risk of being extinct in the wilderness.

• Vulnerable: Species that are at high risk of being endangered in the wilderness.

• Near Threatened: Species that are likely to become endangered in the near future.

• Least Concern: Species which are found in abundance and is not at risk.

• Data Deficient: Species about which we do not have enough data to assess its extinction risk.

• Not Evaluated: Species which has not yet been evaluated on the criteria adopted by the IUCN.

Species that fall in the Critically Endangered, Endangered and Vulnerable categories are also referred to as Threatened Species.

Migration

Migration is the movement of birds, animals or humans over long distances to live in a new location permanently or temporarily.

Migratory birds are birds that fly to far away areas every year to avoid harsh and inhospitable weather conditions in their natural habitat. They cover long distances to reach another land and lay their eggs.

Reforestation

Reforestation is the opposite of deforestation. Here, we plant new trees to restock forests that have been destroyed.

In India, we have the Forest (Conservation) Act which aims to preserve and conserve natural forests and meet the basic needs of the people living in or near them.

Reforestation can happen naturally or can be done artificially. If a deforested area is left undisturbed for some time, the forests grow again. However, we cut more trees than the ones that grow on their own and hence, we should plant trees to promote reforestation.

Ideally, we should plant as many trees as had been cut down and the new trees should be of the same species as the earlier ones.

Padma Shri Jadav 'Molai' Payeng, the Forest Man of India is an environmental activist and forestry worker. He is from Jorhat, India and single-handedly planted and nurtured a forest encompassing an area of 1,360 hectares across several decades along the sandbar of the River Brahmaputra. He was awarded Padma Shri - the fourth highest civilian award in India - in 2015 for the feat. The forest he planted is called 'Molai forest' after him.

--- NCERT Solutions ---

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.
Answer:- 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
Answer:-
(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.

Answer:-

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?

Answer:- 

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.
Answer:- 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.
Answer:- 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.
Answer:- 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.
Answer:- Consider the map given below:

Question 10.- Why should paper be saved? Prepare a list of ways by which you can save paper.
Answer:- 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.- 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 which have vanished.
3. Species found only in a particular habitat.
4. Variety of plants, animals and microorganisms found in an area.
Solution:

--- Frequently Asked Questions ---

Question 1.- What is meant by deforestation ?
Answer:- Deforestation means clearing of forests and using that land for other purpose like building houses and factories.

Question 2.- What is meant by biosphere ?
Answer:- Biosphere is that part of the earth in which living organisms exist or which supports life.

Question 3.- Define biodiversity.
Answer:- Biodiversity means the variety and variability of all microorganisms, plant and animal life.

Question 4.- Name two animals which have become extinct. 
Answer:- The mountain quail of Western Himalyas and the pink head duck.

Question 5.- What are Biosphere reserves ?
Answer:- Biosphere reserves are the areas meant for conservation of microorganisms, plants and animals.

Question 6.- Define species.
Answer:- Species is a group of individuals which are capable of interbreeding with each other.

Question 7.- What are endemic species ?
Answer:- Endemic species are exclusively found in a particular area only in small numbers.

Question 8.- What is meant by Wildlife sanctuaries ?
Answer:- Wildlife sanctuaries are some areas where wild animals are protected and preserved

Question 9.- What are National Parks ?

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

Question 10.- Why has the survival of some animals become difficult ?
Answer:- Survival of some animals has become difficult because of changes in their natural habitat.

Question 11.- What is meant by ecosystem ?
Answer:- 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 12.- What is Red Data Book ?
Answer:- Red Data Book is the source book which keeps a record on population status of the species included in the Red List.

Question 13.- What are migratory birds ?
Answer:- Birds who cover long distances to reach another land are known as migratory birds.

Question 14.- Name the first Reserve Forest of India.
Answer:- Satpura National Park.

Question 15.- Name two wildlife sanctuaries of India.
Answer:- Kangha and Sultanpur.

Question 16.- Kaziranga and Corbett are …………. of India.
Answer:- National parks.

Question 17.- Name two endangered species of animals.
Answer:- The bison and antelope are endangered species of animals.

Question 18.- Why should soil be conserved ?
Answer:- Soil should be conserved to maintain the fertility of the soil.

Question 19.- Name two animal species which have become extinct in the past years.
Answer:- Dodo and thylacine.

Question 20.- Give one word for species found only in a particular area.
Answer:- Endemic species.

Question 21.- Name the organisation that produces the Red List.
Answer:- IUCN (International Union for Conservation of Nature and Natural Resources).

Question 22.- Why do we feel the need for conserving natural resources more than our ancestors did ? Give two reasons.
Answer:- We have to conserves the natural resources because :

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

Question 23.- Differentiate between the following : 

1. Wildlife sanctuary and Biosphere reserve.
2. Zoo and Wildlife sanctuary.
3. Endangered and Extinct species.
4. Flora and Fauna.

Answer:

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 24.- What is the role of small animals in the ecosystem ?
Answer:- The role of small animals is important because they form a part of the food chain and food webs.

Question 25.- Name the flora and fauna of Pachmarhi Biosphere Reserve.
Answer:- Flora – Sal, teak, mango, jamun, silver fern, arjun.
Fauna – Chinkara, blue bull, barking deer, cheetah, leopard, wild dog, wolf.

Question 26.- Name two endemic flora and endemic fauna of Pachmarhi Biosphere Reserve.
Answer:
Endemic flora – Sal and wild mango
Endemic fauna – Bison, Indian giant squirrels and flying squirrels.

Question 27.- Give two reasons why sanctuaries should be maintained.
Answer:

• 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 28.- What are Rock shelters ? Where are they found ?
Answer:- 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 29.- What is Project Tiger ? What is its objective ?
Answer:- Project Tiger was launched on 1st April 1973 by our government to protect the tigers of the country.

Question 30.- Why should paper be saved ?
Answer:- We should save paper because it takes 17 full grown trees to make one tonne of paper.

Question 31.- How can we save paper ?
Answer:- We should reuse used paper and recycle it.

Question 32.- How can the resources be conserved ?
Answer:- Resources can be conserved by :

• not wasting the resources.
• maintaining their quality

Question 33.- Which factors are responsible for cutting of forest ?
Answer:- As man’s need for land used in housing and farming and wood for fuel and construction increased, he started cutting down forests.

Question 34.- Expand

• WWF
• IUCN

Answer:

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

Question 35.- How can overgrazing destroy forests ?
Answer:- 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 36.- How does vegetation help to conserve water ?
Answer:- Vegetation slows down the flow of rain water on land and increases the absorption of water by the soil.

Question 37.- Give the difference between Red List and Red Data Book.
Answer:- 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 38.

1. What is Top soil ?
2. Mention two ways by which soil erosion can be prevented. [DA V (Winter) 2001]

Answer:

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 39.- Mention two steps needed for conserving wildlife. Name two endangered species of animals.
Answer:- 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 40.- “When we conserve forests, we conserve wildlife and soil also”. Discuss.
Answer:- 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 41.- Explain three ways to conserve forests. 
Answer:- 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 42.- How can the cutting of trees affect the ecological balance of a particular area ? [DAV (Winter) 1999]
Answer:- 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 43.- 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

Answer:

1. Sanctuary
2. Endemic species
3. Climatic

Question 44.- 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.

Answer:

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 45.- “Water is renewable but oil is not”. Explain.
Answer:- 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.

Question 46.- What is the difference in conservation of renewable and non-renewable resources ?
Answer:- Conserving of renewable resources is to utilise them in such a way that nature is able to replenish them as fast as they are used. In the case of non-renewable resources it is not so. These resources take a long time in their formation and will get finished very soon. So, they should be used judiciously.

Question 47.- Discuss the effects of deforestation on the following :

1. Wild animals.
2. Environment.
3. Villages (Rural areas).
4. Cities (Urban areas).
5. Earth.
6. The next generation.

Answer:

1. The natural habitat of wild animals is destroyed by deforestation.
2. Deforestation decreases the level of oxygen in the atmosphere and ground water level.
3. In the rural areas deforestation leads to loss in soil fertility and increased chances of natural calamities such as floods and drought.
4. Deforestation will lead to global warming in the cities.
5. On 4he whole earth, deforestation would lead to high temperatures and increased pollution level natural calamities and reduced levels of oxygen and ground water.
6. The next generation would not have enough wood and paper.

Question 48.- 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 ?

Answer:

1. Biodiversity is important for all living creatures for the preservation of environment and for economic reasons. Biodiversity is useful in scientific and medical research.
2. Protected forests are also not safe because people living in the neighbourhood encroach upon them and destroy them.
3. Many tribes still live in the jungle and are depend on the trees and the animals for their survival.
4. Causes of deforestation :
   • Using land for cultivation.
   • Building houses and factories.
   • Making furniture or using wood as a fuel.
   • Forest fires and severe drought.
5. Consequences of deforestation:
   • Increases the temperature and pollution level on the earth.
   • Decreases the level of oxygen in the atmosphere and lowers ground water level.
   • Increases chances of natural calamities.
   • Promotes soil erosion.
6. Migration means movement of the birds to far away specific areas every year during a particular time because of climatic changes.

Question 49.- List the methods by which non-renewable resources can be conserved.
Answer:- Non-renewable resources can be conserved by following methods :

1. Avoid wasteful use of sources.
2. Recycling resources e.g., paper, plastic bottles, etc.
3. Finding substitutes for non-renewable sources of energy, that is using alternative sources of energy such as solar energy, wind energy, etc.
4. Repair and use the appliance rather than discard it as soon as it gets spoilt.

Question 50.- “Conservation of resources means not only using the resources judiciously but also maintaining their quality”. Discuss.
Answer:- This statement is correct because if we have the resources of poor quality, it is of no use. We may have enough water, but if it is polluted it causes more harm than benefit. It causes many diseases in human beings and animals. Polluted air causes more harm in many cities as people get many diseases.

Question 51.- Why is managing of resources not very simple ?
Answer:- Managing resources is not very simple because the problems are inter related. Solving one problem leads to another problem. Banning of insecticides will save wildlife but will lead to shortage of food due to destruction of crops by insects. So, we can say that banning of one thing leads to shortage of another thing.

Question 52.

1. How does planting of trees help to conserve soil ?
2. Why should chemical fertilisers be used with caution ?

Answer:

1. The roots of trees helps to find the soil and prevent soil erosion. Rows of trees planted along the edges of farms act as wind breakers and prevent erosion by wind.
2. Chemical fertilisers damage the porous structure of the soil and also kill soil organisms such as earthworms which add loose fertile soil to the fields.

Question 53.

1. What are endemic species ? “
2. Why are these endemic species ?

Answer:

1. The species which are unique to a specific region are known as endemic species. Sal and wild mango are two example of endemic flora and bison and flying squirels are examples of endemic fauna.
2. These are endemic species because
   • their ecological requirements are met over a small area.
   • they are not capable of moving to other suitable habitats.

Question 54.

1. What are the five conservation categories of wildlife ?
2. How many biosphere reserves, national parks and sanctuaries are there in India ?

Answer:

1. There are five conservation categories of wildlife — extinct, endangered, vulnerable, rare and unsufficiently known species.
2. There are 15 biosphere reserves, 90 national parks and 448 sanctuaries in India.

--- MCQs ---

Question 1.- Conversion of fertile land into deserts is known as
(a) deforestation
(b) desertification
(c) conservation
(d) none of these.
Answer:- (b)

Question 2.- The variety of life on the earth is commonly referred to as
(a) biodiversity
(b) biosphere
(c) afforestation
(d) none of these.
Answer:- (a)

Question 3.- The first national park in India is
(a) Bandipur national park
(b) Kaziranga national park
(c) Jim Corbett national park
(d) Satpura national park.
Answer:- (c)

Question 4.- All type of plant life is known as
(a) fauna
(b) flora
(c) forest
(d) none of these.
Answer:- (b)

Question 5.- When no member of a species exists, it is known as
(a) endemic species
(b) endangered species
(c) extinct
(d) vulnerable species.
Answer:- (c)

Question 6.- Snow leopard is
(a) vulnerable species
(b) endangered species
(c) extinct
(d) endemic species.
Answer:- (b)

Question 7.- A species found only in one particular place is known as
(a) endemic
(b) vulnerable
(c) endangered
(d) extinct.
Answer:- (a)

Question 8.- Migration of birds takes place because
(a) they like to travel
(b) to find abundant food
(c) to meet other birds
(d) none of these.
Answer:- (b)

Question 9.- Growing new trees in forests is known as
(a) deforestation
(b) desertification
(c) afforestation
(d) none of these.
Answer:- (c)

Question 10.- How many Biosphere Reserves in India has the Indian Government established ?
(a) 10
(b) 5
(c) 14
(d) 20
Answer:- (c)

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