NIOS Environmental Science (333) Notes/Answer| Chapter-3|Biodiversity and its conservation

NIOS Environmental Science (333) Notes/Answer| Chapter-3|Biodiversity and its conservation. Important questions for NIOS Environmental Science (333) Questions Answers brings you latest queries and solutions with accordance to the most recent pointers SOS . Students will clear all their doubts with regard to every chapter by active these necessary chapter queries and elaborate explanations that area unit provided by our specialists so as to assist you higher. These queries can facilitate students prepare well for the exams thanks to time constraint .NIOS Environmental Science (333) Notes/Answer| Chapter-3|Biodiversity and its conservation.

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NIOS Environmental Science (333) Notes/Answer| Chapter-3|Biodiversity and its conservation


 1. Define the term biodiversity.

 Ans: The term ‘biological diversity’ commonly shortened to biodiversity refers to the number, variety, and variability of all life forms on earth. These include millions of plants, animals and microorganisms, the genes they contain, and the intricate ecosystems of which they are a part. Biodiversity is usually described at three levels: genetic, species and ecosystem diversity.

 2. Explain with suitable examples genetic diversity, species diversity and ecosystem diversity.

 Ans: Genetic biodiversity: This is the diversity of genes within a species, which are passed down the generations. It is this type of diversity that gives rise to the varieties of species. For example, basmati rice is distinct from joha rice. Some variations are easy to see, such as, size or colour. Taste or flavor can be perceived by other senses. Species biodiversity : Species is the unit used to classify the millions of life forms on earth. Each species is distinct from every other species. Horses and donkeys are distinct species, as are lions and tigers. What unites members of a species is the fact that they are genetically so similar that they can produce fertile offspring. Species diversity is usually measured in terms of the total number of species within a defined area. 

Ecosystem biodiversity:

An ecosystem is a set of life forms (plants, animals, microorganisms) interacting with one another and with non-living elements (soil, air, water minerals, etc.). Ecosystem diversity is, therefore, the diversity of habitats which include the different life forms within itself. It is also used to refer to the variety of ecosystems found within a bio geographical or political boundary. 

3. What are value of biodiversity? 

Ans: Biodiversity may sound like an abstract concept, but in reality it touches almost every aspect of our life. The earth has an enormous variety of plants and animals, both domesticated and wild, as also a wide array of habitats and ecosystems. This diversity meets the food, medicinal, clothing, shelter, spiritual as well as the recreational needs ul’ millions of people around the world. It also ensures that ecological functions such as the supply of clean water, nutrient cycling and soil protection are maintained. In fact, biodiversity loss would mean a threat to the survival of the human race itself. 

4. What is consumptive value?

Ans: We have noticed that the biodiversity products like fuel, food, drugs, fibres etc. have been used by man from time immemorial. About 90 per cent of the world’s food comes from plant species. Genetic diversity is important in breeding crops and livestock. Crop breeders need a diversity of crop varieties in order to breed new varieties that resist evolving pests and disease. The loss of diversity in crop species has severe implications for global food security. A single post invasion or disease could wipe out all standing crops or a particular livestock. About 80 per cent of the people in developing countries depend for primary healthcare on traditional medicine, most of which is derived from plants, and some from animal and mineral sources. We get penicillin used as an antibiotic from a fungus called penicillium. Similarly we get tetracycline from a bacterium, aspirin from the plant Filipendula Ulmaria, and quinine from the bark of cinchona trees. The fuel wood, fossil fuels (like coal, petroleum) , natural gas, minerals etc. have been used by all of us. 

5. What is productive value? 

Ans: These are the commercial products manufactured or prepared II um the different resources of biodiversity. Even today a large number of traditional communities depend wholly or partially, on the surrounding natural resources for their daily needs of food, shelter, clothing, household goods, medicines, fertilizers and entertainment. The tusks of elephants, silk from silk worm, wool from sheep, lac from lac insect are obtained from the animal diversity. Many industries depend largely on plant materials e.g. paper and pulp industry, sugar industry, plywood industry, railway sleeper etc.

 6. What are major threats to biodiversity? 

Ans: Extinction or elimination of species is a natural process of evolution. But in recent past, the elimination of innumerable species have been talked about in different national and international forums. The changing attitude of human society to the environment in general and biodiversity in particular has reached such a level that the conservation of biodiversity has become a great challenge. There have been threats to biodiversity from different angles such as —

  1.  Habitat destruction
  2.  Overgrazing
  3. Poaching 
  4. Natural calamities
  5.  Climate change and global warming
  6.  Biopiracy

 7. What are Ex-situ and In-situ conservation of biodiversity? Give examples of each. 

Ans: a) In-situ Conservation:

 In-situ conservation is conservation of wild species of flora and fauna in their natural habitat i.e. on site preservation. e.g. biosphere reserves, national parks, wildlife sanctuaries, reserve forests etc. India has a long tradition of such conservation. It has continued this through the establishment of a network of protected areas throughout the country. Today, India has over 533 national parks and sanctuaries. These protected areas cover about 4.5 per cent of the country’s territory and have helped in conserving habitats and their biodiversity. Several special projects have also been launched to save certain animal species which have been identified as needing concerted protection effort. Assam now has 5 national parks and 22 wildlife sanctuaries. Kaziranga National Park and Pobitora wildlife sanctuary are involved in the protection of Asiatic Rhino. Kaziranga is also the home of swamp deer, hog deer and elephants. The biosphere reserve, Manas National Park is the home of golden langur and pygmy hog. 

b) Ex-situ Conservation:

Ex-situ conservation is the conservation of plants and animals away from their natural habitat. This could be in zoological parks and botanical gardens or through the forestry institutions and agricultural research centres. A lot of effort is 

under way to collect and preserve the genetic material of crops, animal, bird, and fish species. This work is being done by institutions such as the National Bureau of Plant Genetic Resources, New Delhi, the National Bureau of Animal Genetic Resources, Karnal etc. 

8. What is Biopiracy?

 Ans: Biopiracy is a kind of procurement of biological resources from a country or a place and the subsequent potentisation of their products. The indigenous people of some countries are the treasure house of knowledge and beliefs. Agents of some companies or other middle persons collect their knowledge and valuable living materials and subsequently proceed for potentisation on their own. Thus through unethical means they acquire rights of marketing these products. A number of such cases are found to occur in different countries, Biopiracy of certain high valued bioresources has been a major threat to biodiversity.

 9. Mention two conservation strategies in our country, 


  1.  Environment Protection Act, 1986: This act relates to general measures to protect the environment, such as restriction on industrial and other processes or activities in specified areas. It also deals with prevention of and control over the manufacture, use, release and movement of hazardous substances. 
  2. Wildlife (Protection) Act, 1972 and Wildlife (Protection) Amendment Act, 1991: These deal with restriction and prohibition of hunting of animals, and with the protection of specified plants. They also deal with the setting up and management of sanctuaries and national parks, setting up of the central zoo authority, control of mm: and captive breeding. They also control trade and commerce in wild animals, animal articles and trophies.

 10. In which year the Earth Summit was held?

Ans: In 1992.


 1. Fill in the blanks. 

(a) The forest (conservation) act was adopted in _________


(b) The wildlife (protection) amendment law was accepted in percent of world’s food is obtained in_________


 (c) About_________ percent of world’s food is obtained from plant.

Ans: 90% 

Short Questions with Answers: ▷ Marks: 4/5

1. Name the two hot spots in India.

Ans: Western ghats and eastern Himalayas. 

2. Name the three important categories under which the uses of biodiversity can be described.

 Ans: Ecological services, biological resource, aesthetic and cultural values.

 3. List any two ways by which biodiversity contributes towards cleaner environment. 

Ans: Reduce pollutants, maintenance of gaseous composition of air, degradation of wastes.

 4. List the three objectives of convention of biological diversity signed during the earth summit-1993. 

Ans: Conservation of biological diversity; sustainable use of biodiversity and fair and equitable sharing of benefits arising out of the utilization of genetic resources. 

5. What are the main conservation strategies?

 Ans: Two strategies- i. In-situ and ii. Ex-situ

  •  Habitat protection is the main in-situ approach. The Protected Area Network for habitat protection includes national parks, wildlife sanctuaries, biosphere reserves, sacred groves or sacred forests. 
  • Ex-situ conservation is doen by setting up botanical gardens, zoos, gene banks and seed banks, cryopreservation and preservation of germplasm. 

6. Which are the three levels at which biodiversity occurs? 

Ans: Biodiversity or biological diversity includes 

  1. genetic diversity, 
  2. species diversity and 
  3. ecosystem diversity. 

7. What is the major cause of biodiversity loss?

 Ans: Over exploitation of ecosystems (forest, grasslands, oceans), habitat destruction and pollution are major causes of biodiversity loss. Over exploitation of plants and animals may lead to extinction thus a renewable resource may be lost forever. The over exploitation of living resources must be checked and stopped to conserve and maintain healthy biodiversity for the overall benefit of present and future generations. 

8. List the main causes for the depletion of wildlife.


  • Commercial exploitation
  • Introduction of exotic species
  • Habitat loss/ disturbance in habitat 
  • Domestication 
  • Use of pesticides

 9. Mention some National Conservation Strategies.

Ans: India has several Acts in force which have a bearing on the conservation of biodiversity. Some of these Acts are: 

  1.  Environment Protection Act, 1986 
  2. Forest (Conservation) Act. 1980 
  3. Wildlife (Protection) Act. 1972 and
  4. Wildlife (Protection) Amendment Act.1991 

10. What do you mean by the value of biodiversity? What are the different types of values we may get from biodiversity? 

Ans: The biodiversity meet the food, medicine, clothes, shelter, together with aesthetical and recreational needs. So we put value to the elements of biodiversity individually and as a whole. These values are regarded as the value of biodiversity. The different types of value of biodiversity are- consumptive, productive, social, ethical, aesthetic and optional value.

11. Can there be loss of biodiversity naturally? If so how?

 Ans: There may be loss of biodiversity due to natural reasons. The natural calamities like floods, earthquakes, eruption of volcanoes, tsunamis, storm, drought etc. That may lead to loss of biodiversity. However, the natural reasons for loss of biodiversity. However, the natural reasons for loss of biodiversity regained with span of time.

 12. Name the national environmental agencies. 


  1.  Ministry of Environment and   Forests
  2. Central Pollution Control board
  3. State Pollution Control Board 
  4. Indian Board for Wild Life

 13. What are the main functions of biosphere reserve?

Ans: The main functions of the biosphere reserves are: Conservation: Long term conservation of representatives, landscapes and different types of ecosystems, along with all their species and genetic resources. 

  • Development: Encourages traditional resource use and promote economic development which is culturally, socially and ecologically sustainable.
  • Scientific research, monitoring and education- Support conservation research, monitoring, education and information exchange related to local, national and global environmental and conservation issues. 

NIOS Class 12th Environmental Science (333) Notes/Question Answer

ChaptersChapters NameLink
Chapter 1Basic Concept of EnvironmentClick Here
Chapter 2Ecological ConceptClick Here
Chapter 3Biodiversity and its conservationClick Here
Chapter 4Natural ResourcesClick Here
Chapter 5Environmental PollutionClick Here
Chapter 6Social Issues and EnvironmentClick Here
Chapter 8 (A)Disaster Management: Responsibilities and PrecautionsClick Here
Chapter 8 (B)Road SafetyClick Here

14. Explain the main important elements of biodiversity.


  1.  Genetic diversity
  2. Ecosystem diversity 
  3. Species diversity 

Biodiversity helps in maintaining the balance of the ecosystem on the Earth. It also helps in providing the biological resources like provision of medicine, food for the animals and human population, wood products, diversity of species, ecosystems, genes etc. Biodiversity enriches the Earth for recreation and tourism along with being a major source for educational research and cultural value. Biodiversity plays a very important role in the discovery of drugs and medicines. It is a proven fact that the medicines from nature account for 80% usage in the world’s population. Biological resources provide various industrial materials like fibre, rubber, oil, water, paper, wood etc. The rich biodiversity becomes a sit for tourist attractions and enhances the recreational activities like fishing, trekking, bird watching, etc. It also becomes a muse for the artists and the musicians. If we as humans have a right to exist, then the same goes with other species. We cannot voluntarily cause their extinction for our own purposes.

15. What is the main aim of the biodiversity act? 

Ans: The main aim of biodiversity act and its salient features is to protect forest and wild life following legislations have been enacted. The main intent of this legislation is to protect India’s rich biodiversity and associated knowledge against their use by foreign individuals and organizations without sharing the benefits arising out of such use, and to check biopiracy. 

Long Questions with Answers▷ Marks: 10

1. What are the social, ethnic and aesthetic use of biodiversity products? 

Ans: The social, ethnic and esthetic use of biodiversity products are

Social use: In India, many plants and animals have ritual significance and are associated with religious, spiritual and other cultural uses. Among the auspicious flowers offered in temples are hibiscus, offered to the goddess Kali, and datura flowers offered to Shiva. Similarly different parts of mango, tulsi, lotus, bel tree etc. are in use for different purposes. Various animal species like cow, goat, buffalo are considered sacred on account of their association with different deities. Some animal species are believed to be the vahanas or vehicles of the deities and are hence venerated.

In India and several other countries, pockets of forests have traditionally been set aside because they are believed to be the abode of a particular god. Over the ages, local communities have protected these areas which are called sacred groves. As a result of the protection, these areas are preserved as pockets of rich biodiversity.

Ethical use: Each species is unique and has a right to exist. Humans do not have the right to eliminate any species. Ethics provide the basis for deciding what is right or wrong, good or bad. The world charter for nature, adopted by the United Nations in 1982, states that ‘every form of life is unique warranting respect regardless of its worth to man, and to accord other organisms such recognition, man must be guided by a moral code of action.”

Aesthetic use: Each species and ecosystem adds to the richness and beauty of life on earth. Perhaps no artificial medium can match the sheer joy of watching a sunset over an ocean, the sight of leaping deer, the sound of a singing bird, or the smell of wet earth after the first rains. A natural ecosystem, once destroyed, is impossible to recreate. The number of people who visit a natural site is an indication of its aesthetic value. No one of us want to visit a barren land but we generally try to enjoy the natural beauty by visiting national parks, wildlife sanctuaries or even the forest area. 

2. What are the various threats to biodiversity? 

Ans: Extinction or elimination of species is a natural process of evolution. But in recent past, the elimination of innumerable species have been talked about in different national and international forums. The changing attitude of human society to the environment in general and biodiversity in particular has reached such a level that the conservation of biodiversity has become a great challenge. There have been threats to biodiversity from different angles such as —

  1.  Habitat destruction
  2. Overgrazing 
  3. Poaching
  4. Natural calamities 
  5. Climate change and global warming
  6. Biopiracy 

3. What is the role of common people in conservation of biodiversity?

Ans: Biodiversity is recognized as a global wealth on which on value can be put. Conservation of biodiversity means the proper protection and management of biological wealth with its ecosystems for the benefit of all living organisms including man. Measures have been taken at the international as well as national level to tackle this issue. People can participate in the conservation of biodiversity especially in the in situ conservation process. From time immemorial people have been preserving biodiversity and religious way. i.e. some tribes preserve some areas rich in biodiversity as sacred groves. Moreover, due to use in religious purposes some plants are preserved in the temples and holy places. But this conservation is not sufficient enough, people should think for conservation of biodiversity by getting away from plantations of plants and animal resources. In order to fulfil our greed we should not destroy the forest and reserve areas. By undertaking various means we can also participate in the conservation of biodiversity.

 4. Does the climate change bring loss of biodiversity? If so, why and how? 

Ans: Climate change can bring loss of biodiversity. Climate change is often cited as a serious threat to biodiversity. Due to change in climatic pattern, any species can not tolerate it and hence disappear. There are different views regarding the effect of climate change on agriculture. The centre of origin for most of the crop plants are the tropical and subtropical areas of the world. Moreover, these regions are very rich in biodiversity and the centre of maximum production of crops. These areas are generally prone to the effects of climatic change. So there is always a threat for disappearance of various plants as well as animals 

from these areas. Thereby, mostly affected plants, resources may be lost forever from the biosphere and loss of biodiversity is most probable. 

5. What are various in-situ methods of conservation? 

Ans: The various in-situ methods of conservation are: 

  1.  Protection of habitat: The main strategy for conservation of species is the protection of habitats in representative ecosystems.
  •  National parks and sanctuaries: India is unique in the richness and diversity of its vegetation and wildlife. India’s national parks and wildlife sanctuaries (including bird sanctuaries) are situated Ladakh in the Himalayas to the Southern tip of Tamil Nadu with its rich biodiversity and heritage. Wildlife sanctuaries in India attract people from all over the world as the rarest of rare species are found here. With 96 national parks and over 500 wildlife sanctuaries, the range and diversity of India’s wildlife heritage is unique.
  • Biosphere Reserves: These are representative parts of natural and cultural landscapes extending over large areas of terrestrial or coastal/marine ecosystems which are internationally recognized within UNESCO’s Man and the Biosphere Programme Thirteen biodiversity- rich representative ecosystems, largely within the forest land (total area – 53,000 sq. km.), have been designated as Biosphere Reserves in India. 

The main functions of the biosphere reserves are: 

  • Conservation: Long term conservation of representatives, landscapes and different types of ecosystems, along with all their species and genetic resources.   
  • Development: Encourages traditional resource use and promote economic development which is culturally, socially and ecologically sustainable. 46
  • Scientific research, monitoring and education – Support conservation research, monitoring, education and information exchange related to local, national and global environmental and conservation issues. 
  1. Species-oriented projects: Certain species have been identified as needing a concerted and specifically directed protection effort. Project Tiger, Project Elephant and Project crocodile are examples of focusing on single species through conserving their habitats.
  • Project Tiger-A success in species conservation Tigers which were once abundant in Indian forests have been hunted. As a result tiger population within the country declined drastically from an estimate of 40,000 at the turn of century to 1200 by the 1970. This led to the Project Tiger in 1973 with the objective of conserving and rescuing this species from extinction. 
  • Project Elephant- Project Elephant was launched in February, 1992 to assist states having free ranging populations of wild elephants to ensure long-term survival of identified viable populations of elephants in their natural habitats. • .
  • Crocodile breeding and management project– This project was started in 1976 with FAO – UNDP assistance to save three endangered crocodilian species, namely, the freshwater crocodile, saltwater crocodile and the rare gharial. The project surveyed the crocodile habitats and facilitated their protection through declaration of sanctuaries and National Parks. 

(c) Sacred forests and sacred lakes: A traditional strategy for the protection of biodiversity has been in practice in India and some other Asian countries in the form of sacred forests. These are small forest patches protected by tribal communities due to religious sanctity. 

6. Write a brief note on biodiversity conservation efforts in India.

Ans: In India, several Bills and Action Plans have been passed by the Parliament for the conservation of biodiversity. Some policy and legal frameworks recently developed to protect biodiversity are The Forest (Conservation) Act 1980, The Wildlife (Protection) Act 1972, The Environment (Protection) Act 1986, The National Biodiversity Strategy and Action Plan (NBSAP) 1999 and Biological Diversity Bill 2002. The Bill provides for the constitution of a separate high power National Biodiversity Authority (NBA) to be set up at Chennai. 

The Bill also envisages the setting up of State Biodiversity Boards, which would advise the State Governments on issues relating to conservation of biodiversity and sustainable use of its components.

In India, commendable efforts have been made for in situ conservation of biodiversity. Under Protected Area network, now we have 13 Biosphere Reserves set up in different biogeographic regions of the country, besides 485 wildlife Sanctuaries and 87 National Parks. Some special projects were also started for providing protection to wildlife in their natural habitats. 

The Project Tiger was started with the financial assistance of WWF in 1973 with 9 Tiger Reserves. Now we have 27 tiger reserves covering a total area of 37,761 km². Besides preserving the tiger and its varied habitats, the wild fauna and flora of these habitats have also benefited from the project. 

Other wild animals which have been protected and rehabilitated through such projects are the Asiatic lion, the Blackbuck, the Rhinoceros, the Musk deer, the Hangul and the Gharial. India is also a party to CITES (Convention on 

International Trade in Endangered Species). In India, specific programmes for conservation of wetlands, mangroves and coral reef systems are also started. Major wetlands of India have already been listed under the Ramsar Convention (1981); six internationally significant wetlands of India have been declared as “Ramsar Sites”. Measures for conservation of biodiversity. Efforts have also been made for ex-situ conservation. There are 33 Botanical Gardens, and about 275 Zoos, Deer Parks and Aquaria. The Central Zoo Authority manages all the large Zoos and provides financial assistance to all types of Zoos in the country.

 7. Give two methods of protecting natural ecosystems. 

Ans: Protection of natural ecosystems demands management of human use of the biosphere resources such that they give maximum benefits to the present human generation while maintaining its potential to meet the needs of future human generations. Protection of natural ecosystems to an environmentalist means to protect animals and plants in their natural habitat in totality and not the protection of any one species. It can be achieved by the following methods:

  1.  Species in the detrimental habitats should be shifted to their unexploited natural habitat. Delhi Development Authority along with Delhi University has jointly established a Yamuna Biodiversity park in Delhi to protect and restore natural biodiversity lost from the Yamuna river bank. The same natural habitat is created for the plants and aquatic birds. Within a span of one year after the establishment of the wetland the number of migratory birds has increased remarkably.
  2.  Zones of megadiversity and hot spots of biodiversity should be protected. Megadiversity zones are those regions of the world which have the largest number of species. 200 global  mega diversities have been identified. India is one of the megadiversity countries. Hot spots are the richest and most threatened reservoirs of plant and animal life on the earth. They have a maximum number of endemic species. 25 terrestrial hotspots have been identified for the conservation of biodiversity. They occupy 1.4% of the earth’s surface and 20% of the human population lives in these areas. Western ghats and Eastern Himalayas are two hotspots of India. 

8. Describe various causes of depletion of biodiversity.


 i) Habitat (natural home) destruction may result from clearing and burning forests, draining and filling of wetlands, converting natural areas for agricultural or industrial uses, human settlements, mines, building of roads and other developmental projects. 

This way the natural habitats of organisms are changed or destroyed. These changes either kill or force out many species from the area causing disruption of interactions among the species.

 ii) Introduction of exotic species: Seeds catch on people’s clothes. Mice, rats and birds hitch-hike on ships. When such species land in new places, they breed extra fast due to absence of any enemy and often wipe out the native species already present there. Exotic species (new species entering geographical region) may wipe out the native ones. A few examples are —

  1.  Parthenium hysterophorus (Congress grass- a tropical American weed) has invaded many of the vacant areas in cities, towns and villages in India leading to removal of the local plants and the dependent animals. 
  1.  Nile perch, an exotic predatory fish introduced into Lake Victoria (South Africa) , threatened the entire ecosystem of the lake by eliminating several native species of the small Cichlid fish that were endemic to this freshwater aquatic system. 

iii) Pollution: Air pollution, acid rain destroy forests. Water pollution kills fishes and other aquatic plants and animals. Toxic and hazardous substances drained into waterways kill aquatic life. Oil spills kill coastal birds, plants and other marine animals. Plastic trash entangles wildlife. It is easy to see how pollution is a big threat to biodiversity.

 iv) Population growth and poverty: Over six billion people live on the earth. Each year, 90 million more people are added. All these people use natural resources for food, water, medicine, clothes, shelter and fuel.

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