CBSE Class 12 Biology –Chapter 15 Biodiversity and Conservation- Study Materials



Biodiversity is the diversity of biological organisation ranging from cellular macromolecules to biomes.
Edward Wilson popularized the term ‘biodiversity’.



1. Genetic diversity: Diversity shown by a single species at genetic level. E.g. Rauwolfia vomitoria (Himalaya) shows genetic variation in the potency & concentration of the chemical reserpine. India has more than 50,000 different strains of rice and 1000 varieties of mango.


2. Species diversity: Diversity at species level. E.g. Western Ghats have greater amphibian species than Eastern Ghats.


3. Ecological diversity: Diversity at ecosystem level.

E.g. In India, deserts, rain forests, mangroves, coral reefs, wet lands, estuaries & alpine meadows are seen.




o According to IUCN (2004), more than 1.5 million species described so far.

o According to Robert May’s Global estimate, about 7 million species would have on earth. (He considered the species to be discovered in the tropics. i.e. only 22% of the total species have been recorded so far).

o Animals are more diverse (above 70%) than plants including Plantae and Fungi (22%).

o Among animals, insects are most species rich group (70%, i.e. out of every 10 animals, 7 are insects).

o Number of fungi species is more than the combined total of the species of fishes, amphibians, reptiles & mammals.



o India has only 2.4% of world’s land area, but has 8.1% of the species diversity. India is one of the 12 mega diversity countries of the world. Nearly 45,000 plant species and twice as many of animals have been recorded from India.

o Applying May’s global estimates, India would have more than 1 lakh plant species and 3 lakh animal species.

o Biologists are not sure about total number of prokaryotic species because

· Conventional taxonomic methods are not suitable for identifying microbial species.

· In laboratory, many species cannot be cultured.



i. Latitudinal gradients


Species diversity decreases from the equator to the poles.

Tropics (latitudinal range of 23.5o N to 23.5o S) have more species than temperate or polar areas.

E.g. Number of bird species in different latitudes:

o Colombia (near equator): about 1400 species.

o India (in tropics): > 1200 species.

o New York (41o N): 105 species.

o Greenland (71o N): 56 species.

Tropical forest region like Equador has up to 10 times of vascular plant species as compared to a temperate forest region like the Midwest of USA.

Tropical Amazonian rain forest (South America) is the greatest biodiversity on earth. It contains

o > 40000 species of plants

o 3000 species of fishes

o 1300 species of birds

o 427 species of mammals

o 427 species of amphibians

o 378 species of reptiles

o > 1,25,000 species of invertebrates

Biodiversity (species richness) is highest in tropics because

o Tropics had more evolutionary time.

o Relatively constant environment (less seasonal).

o They receive more solar energy which contributes to greater productivity.

ii. Species- Area relationship

According to the study of Alexander von Humboldt in South American jungles, within a region, species richness increases with increasing explored area, but only up to a limit.

Relation between species richness and area gives a rectangular hyperbola.


S= CAz


S= Species richness

A= Area

C= Y-intercept

Z= slope of the line (regression co-efficient)

On a logarithmic scale, the relationship is a straight line described the equation Log S = log C + Z log A

Generally, for small areas, the Z value is 0.1 to 0.2.

But for large areas (e.g. entire continents), slope of the line is steeper (Z value: 0.6 to 1.2).

E.g. for frugivorous birds and mammals in the tropical forests of different continents, the Z value is 1.15.




According to David Tilman, plots with more species shows less year-to-year variation in total biomass.

Increased diversity contributes to higher productivity. It is essential for ecosystem health and survival of human race.

‘Rivet popper hypothesis’: It is an analogy used to understand the importance of biodiversity.

It is proposed by Stanford ecologist Paul Ehrlich.

In an airplane (ecosystem), all parts are joined with many rivets (species). If passengers pop a rivet (extinction of a species), it may not affect flight safety (functioning of the ecosystem). But as more and more rivets are removed, the plane becomes dangerously weak. Loss of rivets on the wings (key species that drive major ecosystem functions) is more dangerous than loss of a few rivets on the seats or windows.




 IUCN Red List (2004) says that 784 species (338 vertebrates, 359 invertebrates & 87 plants) were extinct in the last 500 years. E.g. Dodo (Mauritius), Quagga (Africa), Thylacine (Australia), Stellar’s sea cow (Russia) and 3 subspecies (Bali, Javan, Caspian) of tiger.

  27 species have been disappeared in the last 20 years.

  More than 15,500 species are facing threat of extinction.

 12% birds, 23% mammals, 32% amphibians, 31% gymnosperm species face the threat of extinction.

 The current extinction rate is 100 – 1000 times faster than in the pre-human times. If this trend continues, nearly 50% species might be extinct within next 100 years.


Impacts of Loss of biodiversity


o Decline in plant production.

o Environmental perturbations such as drought.

o Increased variability in ecosystem processes such as plant productivity, water use and pest & disease cycles.


Causes of Biodiversity losses (‘The Evil Quartet’)


1. Habitat loss and fragmentation: Most important cause.

   E.g. Tropical rain forests (loss from 14% to 6%).

   Thousands of hectares of rain forests are being lost within hours.

   The Amazon rain forest is being cut for cultivating soya beans or for conversion of grass lands for cattle.

   Fragmentation badly affects animals requiring large territories and migratory animals.


2.   Over-exploitation: Stellar’s sea cow, Passenger pigeon etc. extinct due to over exploitation.


3.   Alien species invasions: Alien species cause decline or extinction of indigenous species. E.g.

 Nile Perch introduced in Lake Victoria (East Africa) caused extinction of more than 200 species of cichlid fish.

 Invasive weed species like Parthenium (carrot grass), Lantana and Eicchornia (water hyacinth) caused damage to our native species.

 Illegal introduction of the African Catfish (Clarias gariepinus) for aquaculture is a threat to the indigenous catfishes in our rivers.


4. Co-extinction: When a species becomes extinct, the species associated with it also extinct. E.g.

    Extinction of the parasites when the host is extinct.

    In co-evolved plant-pollinator mutualism, extinction of one causes the extinction of the other.




There are 3 categories of reasons for conservation.


a. Narrowly utilitarian arguments


 Human derive economic benefits from nature such as food, firewood, fibre, construction material, industrial products (tannins, lubricants, dyes, resins, perfumes) and medicines.

  More than 25% of the drugs are derived from plants.

  25,000 species of plants have medicinal value.


b. Broadly utilitarian arguments

Biodiversity has many ecosystem services. E.g.

·    Amazon forest (‘lung of the planet’) produces 20% of total O2 in the earth’s atmosphere.

·   Pollination through bees, bumblebees, birds and bats.

·   Aesthetic pleasures.


c. Ethical arguments


·   Every species has an intrinsic value. We have a moral duty to care for their well-being.


Biodiversity conservation is 2 types: In situ (on site) conservation and Ex situ (off site) conservation.


a. In situ conservation (on site)

It is the conservation of genetic resources within natural or human-made ecosystems in which they occur. E.g. Protected areas such as National Parks, Sanctuaries, Biosphere reserves, cultural landscapes, natural monuments etc.

· National Park: Strictly reserved for the welfare of the wildlife where private ownership, cultivation, grazing etc. are prohibited. E.g. Eravikulam National Park in Kerala.

· Sanctuary: Here, protection is given only to the animals. Collection of timbers, minor forest products and private ownership are allowed so long as they do not harm the animals. E.g. Periyar wildlife sanctuary in Kerala.

· Biosphere Reserves: Areas of land or coastal ecosystems for conservation and sustainable use.

· Sacred forests (Sacred groves): Forest fragments which are communally protected based on religious beliefs. E.g.

o Sacred groves in Khasi & Jaintia Hills in Meghalaya.

o Aravalli Hills of Rajasthan.

o Western Ghat regions of Karnataka & Maharashtra.

o Sarguja, Chanda & Bastar areas (Madhya Pradesh).

India has 14 Biosphere Reserves, 90 National Parks and 448 wildlife sanctuaries. 


b. Ex situ conservation (off site)

It is the conservation of organisms outside their habitats. E.g. genetic resource centres, zoological parks, wildlife safari parks, botanical gardens, gene banks, cryopreservation etc.




· These are the regions with very high species richness, high degree of endemism (species confined only to a specific region) but most threatened.

· There are 34 hotspots in the world.

· 3 hotspots cover India’s biodiversity regions- Western Ghats & Sri Lanka, Indo-Burma and Himalaya.

· All hotspots together cover only < 2% of the earth’s land area. But the species richness is extremely high. Protection of hotspots reduced the ongoing extinctions by 30%.


International Efforts for conserving biodiversity


·  The Earth Summit or Convention on Biological Diversity (Rio de Jeneiro, 1992) – 3 objectives:

a.     Conservation of biodiversity.

b.    Sustainable use of biodiversity.

c.     Sharing of benefits arising from genetic resources.

· The World Summit on Sustainable Development (Johannesburg, South Africa, 2002): 190 countries pledged to reduce the current rate of biodiversity loss.

CBSE Class 12 Biology Important Questions Chapter 15 – Biodiversity and Conservation

1 Mark Questions

Chapter 15
Biodiversity and Conservation

1 Marks Questions
1. Habitat loss and fragmentation has caused severe damage to a particular type of ecosystem. Name it.
Ans. Tropical Rain Forest.

2. What trend is observed in respect of species diversity when we move from equator to poles?
Ans.In general, species diversity decreases as we move away from the equator towards poles.

3. Which region is considered as the one with highest biodiversity on earth? What is the name given to such region.forests?
Ans. Amazonian rain forests. They are also called the ‘Lungs of the planet’.

4. Ecologists have discovered that value of Z lies in range of 0.1 to 0.2 regardless of taxonomic group or region. When will the slope of line steeper in species area relationship?
Ans.Slope of line is much steeper if one analyses the species¡Varea relationship among very large areas like entire continents.

5. Define cryopreservation. Why is it useful in conserving biodiversity?
Ans.Preserving a material in liquid nitrogen at – 196°C. It can be done to preserve threatened species in viable and fertile condition for long period.

6. What is the reason for genetic variation shown by medicinal plant Rauwolfiavomitoria?
Ans.Genetic variation might be in terms of potency and concentration of the active chemical reserpine produced by plant.

7.Expand i) IUCN –
ii) MAB –
Ans. i) IUCN – International union of conservation of mature & natural resources
ii) MAB – man & biosphere programme.

8. What are hot spots?
Ans.Hot spots are the priority areas of conservation that are extremely rich in species have high endemism& under constant threat of extinction.

9. Name any two threatened animal species of India?
Ans.Swamp Deer & Great Indian Rhinoceros

10.Name two most biodiversity rich zones of India?
Ans.Western Ghats & eastern Himalayas. [1]

11.Expand : i) – WWF
ii) – IBWL
Ans.i) WWF – World wildlife fund
ii) IBWL – Indian Board of wild life.

12.What is cryopreservation?
Ans.Cryopreservation is the storage of materials at ultra – low temperature either by rapid cooling or by grade cooling & simultaneous dehydration at low temp.

13.Write the scientific name of the plant that yields reserpine?

14.Name any two conventional methods of ex-situ conservation?
Ans.Botanical garden &zoological parks.

15.What do you mean by “vulnerable species”?
Ans.Species that are believed to move into endangered species category in the near future if the causal factors continue operating are called vulnerable species.

16.Name the national park for Rhinoceros & lion in India respectively?
Ans.Kaziranga national park &Gir National Park respectively.

2 Mark Questions

Chapter 15
Biodiversity and Conservation

2 Marks Questions
1. How many species of plants and animals have been described by IUCN in 2004? What is global species diversity according to Robert May?
Ans.IUCN (2004) has described slightly more than 1.5 million species of plants and animals.
According to Robert May¡¦s estimates the global species diversity is about 7 million.

2. Explain co-extinction with a suitable example.
Ans.Coextinction refers to the disappearance of species with extinction of another species of plant or animal with which it was associated in an obligatory way. e.g., Plant-pollinator mutualism.

3. Study the pie-diagram and answer the questions which follows :
What do A, B, C and D represent in these diagrams.
Ans.A →Crustaceans B →Insects
C →Mosses D →Fungi

4.What is IUCN red list? Give any two uses of this list?
Ans. IUCN (International union of conservation of nature & natural resources) maintains a “Red datalist” which is a catalogue of taxa facing risk of extinction. The main purpose of this list:-
i) to identify & document the species with high risk of extinction.
ii) to provide awareness to the degree of threat to biodiversity.

5.“Species diversity of plants is much less than that of animals” Why?
Ans.The species diversity of plants is much less than that of animals because most animals possesses nervous system that control & coordinate various activities of animals. They also possess receptors to receive environmental stimuli some of these responses are adaptive & ensure survival of organism in changing environmental conditions.

6.What is the difference between in-situ & ex-situ conservation?

In-situ conservationEx-situ conservation
i).It is the process of protecting the species in its natural habitat by protecting or cleaning up the habitati).It is the process of protecting the species lay removing it from unsafe habitat & placing under car.
ii).It helps in recovering population in the surroundings.ii).It help in recovering population under simulated conditions
iii).eg. National park, Biosphere reserves.iii).eg. Botanical garden Gene bank.

7.“Amazonian rain forest in south America has the greatest bio-diversity on earth”. Justify the statement.
Ans.Amazonian rain forest in south America has the greatest biodiversity on earth; it harbors about40000 species of plants, 1,25,000 species of insects, 3000 species of fishes, 427 of amphibians, 378 ofreptiles, 1300 of birds & 427 of mammals.

8.Sometimes introduction of an exotic species upsets native species of the ecosystem. Substantiate the statement with the help of an example?
Ans.The alien species become invasive & compete with native species causing extinction of indigenous species e.g. introduction of African catfish (clariasgariepinus) for aquaculture purposes, is posing threat to our. Indigenous catfish, (clariasbacterachus).

9.What do you mean lay species diversity? Name two measures of species diversity?
Ans.Species diversity refers to the variety of species within a region. The two important measuresOf specie diversity are:-
i) Species richness:- It refers to number of species per unit area.
ii) Species evenness :- It refers to relative abundance with which each species is represented in an area.

10.What are sacred grooves? What is their role in conservation?
Ans. Sacred grooves are sacred forest patches around the places of worship. Tribal people do notallow to cut even a single branch of tree in these sacred grooves due to which many endemicspecies flourish in these region.

11.What do you mean by IPR. What are the drawbacks of IPR.
Ans.IPR refers to Intellectual property rights, under which transformed plants, animals ormicroorganisms can be patented & become exclusive private property.
Drawbacks of IPR:-
i) Increase in price of seeds
ii) Greater domination of agriculture by multinational companies.
iii) Slower diffusion of new varieties
iv) Replacement of local varieties by exotic varieties.

12.Which type of conservation measures – in situ or ex-situ will help the larger number of species to survive? Explain.
Ans.In-situ conservation will help the larger number of species to survive because it providesnatural environment for growth & development of species.

13.What is Biodiversity? Why has it become important recently?
Ans.Biodiversity means the variability among living organisms from all sources including interaliaterrestrial, marine & other aquatic ecosystem & ecological complexes of which, they are parts, thisincludes diversity within species, between species & of ecosystem. In modern times,industrialization civilization, urbanization has developed to large scale use of different species ofplants& animal as a result of which life of several species of organism has been endangered thus,Biodiversity has become so important in recent times.

14.List the important attributes of a stable community?
Ans.i) It shall not show too much of variations in the year – to – year productivity.
ii) It must be either resistant or resilient to seasonal disturbances.
iii) It must be resistant to invasion by alien species.

15.Given below are the representation of global diversity of invertebrates & vertebrates.

Mention the class of organism which belongs to each group in this representation.

 Invertebrates Vertebrates
d-Other animal groupsd-Reptiles

16.Give reason why is it difficult to estimate global diversity for prokaryotes?
Ans.It is difficult to estimate climate diversity of prokaryotes because :-
i) Conventional taxonomic methods are not suitable for identifying microbial species.
ii) Many of these species cannot be cultured under laboratory conditions.
iii) Biochemical & molecular biology techniques would put their diversity into millions.

3 Mark Questions

Chapter 15
Biodiversity and Conservation

3 Marks Questions
1. Hot spots are the regions of exceptionally high biodiversity . But they have become regions of accidental habitat loss too. Name the three hot spots of our country. Why are they called ‘Hot spot’?
Ans.Westerm Ghats and Sri lanka; Indo-Burma; Himalaya called ¡¥biodiversity hot spots¡¦ as they show
(i) High level of species richness
(ii) High degree of

2. Study the diagram of the earth given below . Give the name of the pattern of biodiversity therein. Suggest any two reasons for this type of occurance.

Ans. Latitudinal gradients
(i) More solar energy available in tropics, more productivity.
(ii) Tropical environments are less seasonal, so more predictable.

3. What is so special about tropics that might account for their greater biological diversity?
Ans.a) Speciation is a function of time, unlike temperate regions subjected to frequent glaciations in the past, tropical latitude have remained relatively undisturbed for million of years and thus had long evolutionary time for species diversification
b) Tropical environment are less seasonal, more const ant and predictable
c) More solar energy awailable in the tropics contributing to high productivity leading to greater diversity .

4.What do you mean by biodiversity? What are the different types of Biodiversity?
Ans. Biodiversity can be defined as the totality of genes species & ecosystem of a given region.
Three important components of Biodiversity are:-
i) Genetic Biodiversity:- It refers to the diversity of genes within a species, Greater the genetic diversity amongorganisms of a species. More sustenance it has against environmental perteburations whereas geneticallyuniform populations are highly prone to diseases or harsh environment
ii) Species Biodiversity:- It refers to variety of species within a region. It has two important measures :-
a) Species richness:- i.e. number of species per unit area.
b) Species evenness:- i.e. abundance with which each species is represented in an area.
iii) Ecosystem Biodiversity:- It refers to variation of habitats, community types & abiotic environment present in an area. It is further of three types:-
a) αα – diversity- It refers to number of species in a given community.
b) ββ– diversity – biodiversity which appears in range of communities due to replacement ofspecies with change in community is called ββ– diversity.
c) γγ– diversity – It refers to diversity of habitats over the total geographical area.

5.What do you mean by latitudinal gradient? What could be the possible reasons for diversity between tropic & temperate region?
Ans. Latitudinal gradient in diversity means that species diversity usually decreases as we move away fromequator towards the poles, Tropic area of latitudinal range 23.50c harbor more species than temperate orpolar area. Three hypothesis have been proposed to explain this difference:-
i) Speciation is a function of time, which temperate regions were subjected to frequent glaciations in the past,the tropics have remain unchanged & hence evolved more species diversity.
ii) As compared to temperate region, tropical environment are less seasonal, relatively more constant &predictable; such constant environment have promotes niche specialization & greater species diversity.
iii) There is more solar radiation avail able in tropical region this contributes directly to greater productivity &indirectly to greater species diversity.

6.Why is it necessary to conserve biodiversity?
Ans.The reasons for conserving biodiversity can be grouped into three categories.
i) Narrow utilitarian reasons:- Human beings derive a number of economic benefits like food, fibre,firewood, industrial product & medicinal products.
ii) Broad utilitarian reasons:- Biodiversity plays a major role in providing ecosystem services like :-
a) production of oxygen
b) Pollination of flowers, without which seeds or fruits are not produced.
c) Aesthetic pleasures like bird watching, watching spring flowers, walking through thick forest, workingup to bulbul’s song etc.
iii) Ethical reasons :- Every species has an intrinsic value even if it is not of any economic value to us-wehave a moral duty to care for their well-being & pass on the biological legacy in a proper from to ourfuture generation.

7.What is the relation between species richness & area? What is the significance of slope of regression?
Ans.Alexander Von Humboldt has observed that within a region, species richness increased withincrease explored area but only upto a limit thus the relationship between species richness & area for anumber of taxa is found to be a rectangular hyperbola. On a log scale, the relation ship becomes linear & is described layequation
Log S = log C + Z log A
The values of slope of regression are identical regardless of the taxonomic group or the region. When such analysis is made among very large areas, the slope ofregression would be much steeper.

8.What are the different approaches for biodiversity conservation in India?
Ans.There are two major approaches for conservation of biodiversity:-
i) In-situconservation :- It is the process of protecting the endangered species of plant or animal in thenatural habitat lay either protecting or cleaning up the habitat or by defending species from predators Itincludes:-
a) Biosphere Reserves:- There are 425 biosphere reserve in the world of which 14 are in India. Hotspotshave been identified for maximum protection to endemic or endangered species.
b) National park or wildlife Sanctuaries:- India has about 90 national parks & 448 wildlife sanctuaries.
c) Sacred forests:- These are undisturbed forests without any human intervention & are surrounded by highly degraded landscapes.
ii) Ex- situ Conservation:- It is the process of protecting the endangered species of plants or animals by removing it from threatened habitat & placing them under care of humans. It includes :-
a) Botanical garden, zoological park and arboreta are conventional methods of ex-situ conservation
b) Cryopreservation to the storage of materials at ultra low temperature either by rapid cooling or by gradual cooling & simultaneous dehydration at low temperature.

9.Give an account of Biodiversity in India?
Ans.India is one of the 10th mega biodiversity countries of the world because of the presence of variety ofclimatic conditions prevailing on different ecological habitat ranging from tropical, subtropical,temperate, So far as biodiversity of India is concerned, it comprises about 47,000 plants & 81,000 animalspecies. India occupies 2-4% of total land area of would but in terms of biodiversity, India contributeabout 10-35% of global diversity.
A large number of species is native of India. About 5000 species of flowering plants belonging to 141genera& 47 families had a birth in India. There are 62% of amphibian species& 50% of lizards endemicto our country with large number in Western Ghats. India is an origin place of 166 species of crop plants& 320 species of wild relatives of cultivated crop. India is rich in marine biodiversity lying along coastlineof 7500 km. There are two hotspots located in India out of 25 in would – These are Western Ghats&Eastern Himalayas.

10.What is the significance of Biodiversity to Human beings?
Ans.Biodiversity provide numerous direct or indirect services to human beings. These are-
i) Source of food & improved varieties:- Biodiversity directly or indirectly adds as the source of food,cloth& shelter.
ii) Fats & Oils:- A variety of plants are used to extract different kinds of oils.
iii) Fibres:- A variety of plants eg. cotton, hemp, jute are chief sources of fibres.
iv) Resins:- Resins are sticky exudation of plants.
v) Gums, Timber, Paper, Tannins, Dyes:- Plants species provide variety of useful products eg. gums,raisins, dyes, similarly animal species provide leather, fur, honey, silk, pearl etc.
vi) Drugs & Medicines:- Hiving organism also contain number of therapeutically useful substances.
vii) Stability of Ecosystem:- The food web, food chain energy flow in various tropic level & biochemical cycles occurs in natural ways without any hindrance if there is proper availability of diversified species
viii) Aesthetic, Scientific & Recreational values :- Indian people grow many plants because they regard them as sacred.

5 Marks Questions

Chapter 15
Biodiversity and Conservation

5 Marks Questions
1. Why is the sobriquet ‘The Evil Quartet’ used in context of biodiversity? Name the members of this quartet. Why do we grieve for the genes when a species is lost?
Ans.The ‘Evil Quartet’ is used as a sobriquet to refer to the cause of loss ofbiodiversity :
(i) Habitat loss and fragmentation :When large habitats are broken up into smaller fragments due to various human activities, the animals requiring large territories (elephants, birds etc.) are badly affected and their populations decline.
(ii) Over-exploitation :When need of a resource becomes greed. e.g., over exploitation of passenger pigeon led to its extinction. Also marine fish is at brink of being endangered due to over exploitations.
(iii) Alien species invasion :Intentional or non-Intentional introduction of a species to a nearby area may disturb the harmony of existing species. e.g., Eichhornia after introduction posed a big threat to thenative species.
(iv) Co-extinction :Extinction of one species invariably leads to extinction of another when they are associated with each other in an obligatory way . e.g., when host species is extinct, obligate parasites dependent on it also die.
(v) We grieve for the loss of genes, because the wild forms are hardy and more resistant to pathogen attack and can be beneficial in crop breeding programmes.

2. Describe at least two approaches each for ex-situ conservation and in situ conservation as a strategy for biodiversity conservation.
Ans. In situ conservation :
(i) Identification and maximum protection of ‘hot spots’
(ii) Legal protection to ecologically rich areas.
(iii) Biosphere reserves, national parks and sanctuaries
(iv) Sacred groves.
Ex situ Conservation :
(i) Creation of zoological parks, botanical garden, wild life sanctuary
(ii) Cryopreservation
(iii) Seed bank.

3.Mention the major causes for loss of biodiversity?
Ans.The four major causes for loss of Biodiversity are :-
i) Habitat loss & fragmentation of crops or conversion into grassland for raising beef-cattle. Total loss ofhabitat deprives many plants & animals their hone & they face extinction. Similarly when a large Habrabecomes fragmented, animals requiring large territory& those with migratory habits are adverselyaffected.
ii) Over exploitation :- when nature is over-exploited be man for natural resources, many species become extinct.
iii) Invasion of alien species:- The alien species became invasive & compete with native species & cause extinction of indigenous species.
iv) Co-extinction:- Co-extinction is a phenomenon in which when a species become extinct, the plant &animal species associated with it in an obligatory manner & become extinct

Biodiversity and Conservation Class 12 Biology MCQs

Question 1.
The one-horned rhinoceros is specific to which of the following sanctuaries ?
(a) Bharatpur
(b) vedanthgol
(c) Kaziranga
(d) Corbett Park
(c) Kaziranga

Question 2.
Which of the following is not an example of in situ conservation ?
(a) Biosphere reserves
(b) National parks
(c) Wildilife sanctuaries
(d) Zoological parks
(d) Zoological parks

Question 3.
One of the ex situ conservation methods for endangered species is
(a) wildlife sanctuaries
(b) biosphere reserves
(c) cryopreservation
(d) national parks.
(c) cryopreservation

Question 4.
Cryopreservation is the preservation of germplasm at very low temperature of around
(a) – 121°C
(b) – 196°C
(c) 0°C
(d) – 101°C
(b) – 196°C

Question 5.
What is common to the seed banks, orchards, tissue culture and cryopreservation ?
(a) All are in situ conservation methods.
(b) All are ex situ conservation methods.
(c) All require ultramodern equipment and very large space.
(d) All are methods of conservation of extinct organisms.
(b) All are ex situ conservation methods.

Question 6.
First ‘Earth Summit’ for ‘Convention on Biological Diversity’ (CBD) was held at
(a) Johannesberg (2002), South Africa
(b) Rio de Janeiro (1992), Brazil
(c) Dehradun (1992), India
(d) New York (2000), U.S.A.
(b) Rio de Janeiro (1992), Brazil

Question 7.
Symbol of WWf is
(a) tiger
(b) Rhododendron
(c) white bear
(d) giant panda.
(d) giant panda.

Question 8.
Which of the following countries has the highest biodiversity ?
(a) Brazil
(b) South Africa
(c) Russia
(d) India
(a) Brazil

Question 9.
Which of the following is not a cause for loss of biodiversity ?
(a) Destruction of habitat
(b) Invasion by alien species
(c) Keeping animals in zoological parks
(d) Over-exploitation of natural resources
(c) Keeping animals in zoological parks

Question 10.
Which of the following is not an invasive alien species in the Indian context ?
(a) Lantana
(b) Cynodon
(c) Parthenium
(d) Eichhornia
(b) Cynodon

Question 11.
The term biodiversity is popularised by
(a) Odum
(b) Paul Ehrlich
(c) Edward Wilson
(d) Tilman.
(c) Edward Wilson

Question 12.
Western ghats have a greater number of amphibian species than the Eastern ghats. What kind of diversity does it represent ?
(a) Species diversity
(b) Genetic diversity
(c) Ecological diversity
(d) None of these
(a) Species diversity

Question 13.
The diversity of organisms sharing the same habitat or community is termed as
(a) alpha diversity
(b) beta diversity
(c) gamma diversity
(d) delta diverstiy
(a) alpha diversity

Question 14.
Alpha diversity is biodiversity present
(a) within community
(b) between communities
(c) ranges of communities
(d) none of these.
(a) within community

Question 15.
A more conservative and scientifically sound estimate about the total number of species present on earth, was made by
(a) Robert May
(b) Paul Ehrlich
(c) David Tilman
(d) Both A and B.
(a) Robert May

Question 16.
What is the total number of species present on earth as estimated by Robert May ?
(a) 3 million
(b) 5 million
(c) 7 million
(d) 9 million
(c) 7 million

Question 17.
India is one of the 17 megadiversity countries of the world and is being divided into ________ biogeographical regions.
(a) 8
(b) 10
(c) 16
(d) 18
(b) 10

Question 18.
Species diversity ______ as one moves from high to low altitudes.
(a) increases
(b) decreases
(c) first increases then decreases
(d) first decreases then increases
(a) increases

Question 19.
Tropics (23.5°N to 23.5°S) have _________ species as compared to temperate or polar regions.
(a) less
(b) equal
(c) more
(d) none of these
(c) more

Question 20.
For frugivorous birds and mammals in the tropical forests of different continents, the slope is found to be
(a) 0.6
(b) 1.3
(c) 1.15
(d) 1.7
(c) 1.15

Question 21.
Where among the following will you find pitcher plant ?
(a) Rainforest of North-East India
(b) Sunderbans
(c) The Desert
(d) Western Ghats
(a) Rainforest of North-East India

Question 22.
Which one of the following is not a feature of biodiversity hotspots ?
(a) Large number of species
(b) Abundance of endemic species
(c) Mostly located in the polar regions
(d) Mostly located in the tropics
(c) Mostly located in the polar regions

Question 23.
What is common to the following plants : Nepenthes, Psiiotum, Rauwolfia and Aconitum ?
(a) All are ornamental plants.
(b) All are phylogenic link species.
(c) All are prone to over exploitation.
(d) All are exclusively present in the Eastern Himalayas.
(c) All are prone to over exploitation.

Question 24.
The one-horned rhinoceros is specific to which of the following sanctuary ?
(a) Bhitar Kanika
(b) Bandipur
(c) Kaziranga
(d) Corbett park
(c) Kaziranga

Question 25.
Which one of the following is an endangered plant species of India ?
(a) Rauwolfia serpentina
(b) Santalum album (Sandalwood)
(c) Cycas beddonei
(d) All of the above
(b) Santalum album (Sandalwood)

Question 26.
What is common to Lantana, Eichhornia and African catfish ?
(a) All are endangered species of India.
(b) All are keystone species.
(c) All are mammals found in India.
(d) All the species are neither threatened nor indigenous species of India.
(d) All the species are neither threatened nor indigenous species of India.

Question 27.
The extinction of passenger pigeon was due to
(a) increased number of predatory birds
(b) over exploitation by humans
(c) non-availability of the food
(d) bird flu virus infection.
(b) over exploitation by humans

Question 28.
Which of the following statements is correct ?
(a) Parthenium is an endemic species of our country.
(b) Arican catfish is not a threat to indigenous catfishes.
(c) Steller’s sea cow is an extinct animal.
(d) Lantana is popularly known as carrot grass.
(c) Steller’s sea cow is an extinct animal.

Question 29.
Which of the following forests is known as the ‘lungs of the planet earth’ ?
(a) Taiga forest
(b) Tundra forest
(c) Amazon rainforest
(d) Rainforests of North East India
(c) Amazon rainforest

Question 30.
The active chemical drug reserpine is obtained from
(a) Datura
(b) Rauwolfia
(c) Atropa
(d) Papaver.
(b) Rauwolfia

Question 31.
Which of the following group exhibit more species diversity ?
(a) Gymnosperms
(b) Algae
(c) Bryophytes
(d) Fungi
(d) Fungi

Question 32.
Which of the below mentioned regions exhibit less seasonal variations ?
(a) Tropics
(b) Temperates
(c) Alpines
(d) Both (a) and (b)
(a) Tropics

Question 33.
The historic convention on Biological Diversity held in Rio de Janeiro in 1992 is known as
(a) CITES Convention
(b) The Earth Summit
(c) G – 16 Summit
(d) MAB Programme.
(b) The Earth Summit

Question 34.
Who confirmed communities with more species tend to be more stable than those with less species ?
(a) Alexander von Humboidt
(b) David Tilman
(c) Paul Ehrlich
(d) Edward Wilson
(b) David Tilman

Question 35.
Rivert popper hypothesis was given by
(a) Paul Ehrlich
(b) Alexander von Humboldt
(c) David Tilman
(d) Robert May.
(a) Paul Ehrlich

Question 36.
Organisation responsible for maintaining Red Data Book is
(a) IUCN
(b) WWF
(d) IBWL.
(a) IUCN

Question 37.
Red Data Book deals with
(a) organisms on the verge of extinction
(b) endemic plants
(c) organisms showing photoperiodism
(d) organisms that are extinct.
(a) organisms on the verge of extinction

Question 38.
How many species are documented to be extinct in last 500 years by IUCN Red List, 2004 ?
(a) 2,000
(b) 87
(c) 567
(d) 784
(d) 784

Question 39.
Bali, Javan and Caspian are
(a) species of tiger
(b) species of Cheetah
(c) subspecies of cheetah
(d) subspecies of tiger.
(d) subspecies of tiger.

Question 40.
Antilope cervicapra (black buck) is
(a) near threatened
(b) endangered
(c) critically endangered
(d) extinct in the wild.
(a) near threatened

Question 41.
A critically endangered animal is
(a) passenger pigeon
(b) dodo
(c) great Indian bustard
(d) zebu.
(c) great Indian bustard

Question 42.
The term “the evil quartet” is related with four major causes of
(a) forest loss
(b) population explosion
(c) air pollution
(d) biodiversity losses.
(d) biodiversity losses.

Question 43.
An exotic species that is introduced to a new area, spreads rapidly and eliminates native species is called
(a) immigrant species
(b) invasive species
(c) destructive species
(d) none of these.
(b) invasive species

Question 44.
Introduction of Nile Perch in lake Victoria of South Africa resulted in
(a) excessive growth of water weeds
(b) elimination of water weeds
(c) elimination of many species of cichlid fish
(d) excessive growth of cichlid fish.
(c) elimination of many species of cichlid fish

Question 45.
The exotic speices, which when introduced in India became notorious weed, is
(a) Lantana camara
(b) Eicchornia crassipes
(c) Parthenium hysterophorus
(d) all of these.
(d) all of these.

Question 46.
Introduction of alien species into new area poses a threat to extinction of indigenous species due to
(a) their high nutrient requirement
(b) their symbiotic relationship
(c) absence of their natural predators
(d) more intraspecific competition.
(c) absence of their natural predators

Question 47.
The reasons behind conserving biodiversity have been grouped into which of the following categories ?
(a) Narrowly utilitarian
(b) Broadly utilitarian
(c) Ethical
(d) All of these
(d) All of these

Question 48.
__________ is the exploration of molecular, genetic and species-level diversity for gaining the products of economic importance.
(a) Exploitation
(b) Bioprospecting
(c) Co-extinction
(d) Patenting
(b) Bioprospecting

Question 49.
Amazon rainforests are considered as ‘lungs of the planet’ as they contribute ___________of the total oxygen in the earth’s atmosphere.
(a) 10%
(b) 15%
(c) 20%
(d) 30%
(c) 20%

Question 50.
‘Broadly utilitarian’ argument for the conservation of biodiversity does not include
(a) bioprospecting
(b) pollination
(c) aesthetic value
(d) climatic regulation.
(a) bioprospecting

Question 51.
Waking up to a bulbul’s song in the morning is related to
(a) narrow utilitarian
(b) broadly utilitarian
(c) ethical
(d) climatic regulation.
(b) broadly utilitarian

Question 52.
Exsitu conservation is used for the conservation of
(a) all plants
(b) all animals
(c) threatened animals and plants
(d) both (a) and (b).
(c) threatened animals and plants

Question 53.
Conservation in the natural habitat is
(a) in situ
(b) ex situ
(c) zoo
(d) botanical garden.
(a) in situ

Question 54.
Presently, total number of biodiversity hotspots in the world is
(a) 25
(b) 34
(c) 37
(d) 40.
(b) 34

Question 55.
Which one of these is not included in the biodiversity hotspots of India ?
(a) Western Ghats
(b) Himalayas
(c) Indo-Burma
(d) North Indian Plains
(d) North Indian Plains

Question 56.
Ecological hotspots present in India are
(a) one
(b) two
(c) three
(d) five.
(c) three

Question 57.
Which pair of geographical area shows maximum diversity in our country ?
(a) Sunderbans and Rann of Kutch
(b) Eastern Ghats and Western Ghats
(c) Eastern Himalayas and Western Ghats
(d) Kerala and Punjab
(c) Eastern Himalayas and Western Ghats

Question 58.
In a national park, protection is provided to
(a) flora and fauna
(b) entire ecosystem
(c) fauna only
(d) flora only.
(b) entire ecosystem

Question 59.
__________ National Park was the first national park of India.
(a) Jim Corbett
(b) Nanda Devi
(c) Kaziranga
(d) Jaldapara
(a) Jim Corbett

Question 60.
First biosphere reserve was established in 1986 at
(a) Nilgiri
(b) nanda Devi
(c) Rann of Kutch
(d) Sunderbans.
(a) Nilgiri

Question 61.
Nanda Devi biosphere reserve is found in
(a) Uttaranchal
(b) Assam
(c) Himachal Pardesh
(d) Andhra Pradesh.
(a) Uttaranchal

Question 62.
MAB Programmed means
(a) Man and biosphere programme
(b) Man and biodiversity conservation programme
(c) Manually aided biosphere conservation programme
(d) None of these.
(a) Man and biosphere programme

Question 63.
Which of these organisms are protected by people of ‘Bishnoi’ community of Rajasthan ?
(a) Prosopis cineraria
(b) Black buck
(c) Bhojpatra
(d) Both (a) and (b)
(d) Both (a) and (b)

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