NEET Biology: Ecology · Chapter 3

Biodiversity and Conservation

What to remember

Biodiversity has three levels: genetic diversity, species diversity and ecological diversity. India is one of 12 megadiversity countries and holds about 8.1% of the global species diversity.
Species richness falls from the equator to the poles, and rises with area as log S = log C + Z log A. Z is about 0.1 to 0.2 for regions within a continent and 0.6 to 1.2 for very large areas such as continents.
The "evil quartet" is the set of four main causes of biodiversity loss: habitat loss and fragmentation, over-exploitation, alien species invasions and co-extinctions.
Conservation is in situ (hotspots, biosphere reserves, national parks, sanctuaries, sacred groves) or ex situ (zoos, botanical gardens, safari parks, cryopreservation, seed banks).

Biodiversity and its three levels

Biodiversity is the variety of life on earth at all levels. The term was popularised by the sociobiologist Edward Wilson. It has three levels.

Level	Meaning	Example
Genetic diversity	Variation in genes within a species	Rauwolfia vomitoria (the source of reserpine) shows variation in the potency and concentration of the active chemical in different regions of the Himalayas. India has more than 50,000 genetically different strains of rice and about 1,000 varieties of mango.
Species diversity	Variety of species in a region	The Western Ghats have a greater amphibian species diversity than the Eastern Ghats.
Ecological (ecosystem) diversity	Variety of ecosystems or habitats	India has deserts, rain forests, mangroves, coral reefs, wetlands, estuaries and alpine meadows, so it has a greater ecosystem diversity than a Scandinavian country like Norway.

How many species are there?

About 1.5 million species have been described so far (IUCN estimate). More than 70 per cent of them are animals and about 22 per cent are plants, algae and fungi together.
Among animals, insects are the most species-rich group: more than 70 per cent of all species recorded are insects.
The number of fungal species in the world is more than the combined total of fishes, amphibians, reptiles and mammals.
Many species remain undiscovered, particularly in the tropics. A global estimate by Robert May is about 7 million species. Only a part of the earth's species has been described.
India has only about 2.4 per cent of the world's land area, but it has about 8.1 per cent of the global species diversity. So India is one of the 12 megadiversity countries of the world.
India has about 45,000 plant species and about twice as many species of animals.

Patterns of biodiversity

Latitudinal gradients. Species diversity decreases as we move away from the equator towards the poles. Tropical areas (between 23.5°N and 23.5°S) have the greatest number of species. Examples: Colombia near the equator has about 1,400 species of birds, New York at 41°N has about 105 species and Greenland at 71°N has about 56 species. India, with a large tropical area, has more than 1,200 species of birds. The Amazon rain forest in South America has the greatest biodiversity on earth, with more than 40,000 plant species.

Why are the tropics rich in species? Three reasons:

1. Time: tropical latitudes have remained relatively undisturbed for millions of years, so there was a long evolutionary time for species diversification. Temperate regions were subjected to frequent glaciations.
2. Constant environment: the tropical environment is less seasonal, relatively more constant and predictable. This promotes niche specialisation and greater species diversity.
3. More solar energy: the tropics receive more solar energy, which contributes to higher productivity and, indirectly, more diversity.

Species-area relationships. Alexander von Humboldt observed that within a region, species richness increases with increasing explored area, but only up to a limit. The relationship is a rectangular hyperbola. On a logarithmic scale the relationship is a straight line, described by the equation:

log S = log C + Z log A

Symbol	Meaning
S	Species richness
A	Area
Z	Slope of the line (regression coefficient)
C	Y-intercept

The value of Z is about 0.1 to 0.2, regardless of the taxonomic group or the region (for example, plants in Britain, birds in California or molluscs in New York State).
When analysing species-area relationships among very large areas such as whole continents, the slope of the line is much steeper. Z lies between 0.6 and 1.2. For example, frugivorous birds and mammals in tropical forests of different continents.

Importance of species diversity to the ecosystem

Scientists have debated whether species richness is essential for ecosystem function.

Stability. David Tilman's long-term experiments on plots showed that plots with more species had less year-to-year variation in total biomass. They also showed increased productivity. A community with more species is more stable.
Rivet popper hypothesis (Paul Ehrlich): in an airplane (the ecosystem), all rivets (species) joined together make the plane work. Passengers keep popping rivets from the wing. Losing one rivet may not matter, but as more are lost the plane becomes weak and finally crashes. In the same way, the loss of a few species may not be a problem now, but if more are lost the ecosystem can collapse. Some species, like the rivets on the wing, are more critical than others.

Loss of biodiversity

Biological wealth is decreasing rapidly. Over the last 500 years, about 784 species (including 338 vertebrates, 359 invertebrates and 87 plants) have become extinct. Recent extinctions that are often named:

Species	Place
Dodo	Mauritius
Quagga	Africa
Thylacine (Tasmanian wolf)	Australia
Steller's sea cow	Russia
Three subspecies of tiger	Bali, Java and Caspian region

Many species are listed in the IUCN Red List as threatened (categories such as critically endangered, endangered and vulnerable). The IUCN Red List is the global catalogue of the status of species. About 12 per cent of bird species, 23 per cent of mammals, 32 per cent of amphibians and 31 per cent of gymnosperms are threatened with extinction.

Causes of biodiversity loss: the evil quartet

Cause	Details and examples
Habitat loss and fragmentation	The most important cause of extinction. Tropical rain forests, which once covered more than 14 per cent of the earth's land surface, now cover no more than about 6 per cent. The Amazon rain forest ("the lungs of the planet") is being cleared for soya bean cultivation and cattle pastures. Fragmentation affects mammals and birds that need large territories, and migratory animals.
Over-exploitation	Excess use of natural resources. Examples: Steller's sea cow and the passenger pigeon were driven to extinction by over-hunting. Many marine fish populations are over-harvested.
Alien species invasions	Introduced species become invasive and cause the decline or extinction of native species. Examples: the Nile perch introduced into Lake Victoria led to the extinction of more than 200 species of cichlid fish; the weeds Parthenium (carrot grass), Lantana and water hyacinth (Eichhornia) are harmful invaders; the African catfish Clarias gariepinus introduced for aquaculture is threatening the indigenous catfishes in Indian rivers.
Co-extinctions	When a species becomes extinct, the plant and animal species associated with it in an obligatory way also become extinct. Examples: when a host fish species becomes extinct, the parasites exclusively dependent on it also become extinct; a coevolved plant-pollinator mutualism, where the extinction of one leads to the extinction of the other.

Why should we conserve biodiversity?

The reasons are grouped into three.

Category	Meaning	Examples
Narrowly utilitarian	Direct economic benefits	Food, firewood, fibre, construction material; industrial products such as tannins, lubricants, dyes, resins and perfumes; medicines. More than 25 per cent of the drugs sold worldwide come from plants, and about 25,000 plant species are used by native people. Bioprospecting is the search for commercially valuable products from nature.
Broadly utilitarian	Services that biodiversity provides	Photosynthesis, which releases oxygen; pollination by bees, bats and birds; control of climate and pollution; aesthetic pleasures.
Ethical	Every species has an intrinsic value, even if it is of no economic use now. We have a moral duty to care for species and pass on the biological legacy to future generations.

The claim that one forest, the Amazon, produces a fixed large share of the earth's oxygen is a popular statement that is not reliable. A forest also uses oxygen in respiration, so its net addition of oxygen is small. The broader point is that forests take up carbon dioxide and support global climate and species diversity.

How do we conserve biodiversity?

In situ conservation (on site) protects the species in its natural habitat. This is the best method because the whole ecosystem is protected. Ex situ conservation (off site) protects the species outside its natural habitat.

In situ methods

Biodiversity hotspots: regions with very high species richness, a high degree of endemism (species found nowhere else) and under threat from habitat loss. There are 34 hotspots in the world. Three of them cover our country: Western Ghats and Sri Lanka, Indo-Burma and Himalaya. Hotspots cover less than 2 per cent of the earth's land area. Protecting them can reduce the mass extinction.
Protected areas: ecologically unique and biodiversity-rich regions are legally protected as biosphere reserves, national parks and sanctuaries. In a national park, human activities such as grazing, forestry and cultivation are not allowed. India also has many such areas across its states.
Sacred groves: forest patches protected by communities on religious grounds, where all trees and wildlife are venerated. They are found in the Khasi and Jaintia Hills of Meghalaya, the Aravalli Hills of Rajasthan, the Western Ghats region of Karnataka and Maharashtra, and the Sarguja, Chanda and Bastar areas of Madhya Pradesh. They are a form of in situ conservation.

Ex situ methods

Zoological parks, botanical gardens and wildlife safari parks.
Cryopreservation: gametes of threatened species are preserved in viable and fertile condition for long periods at very low temperature (in liquid nitrogen at −196°C). Eggs can be fertilised in vitro, and plants can be propagated using tissue culture methods.
Seed banks: seeds of different genetic strains of commercially important plants are kept for long periods.

Method	Type	Example
Biodiversity hotspot	In situ	Western Ghats and Sri Lanka
National park	In situ	Area with no grazing or cultivation
Sacred grove	In situ	Khasi and Jaintia Hills
Zoo	Ex situ	Captive breeding of threatened animals
Cryopreservation	Ex situ	Gametes stored in liquid nitrogen
Seed bank	Ex situ	Genetic strains of crop plants

International efforts

The Earth Summit at Rio de Janeiro in 1992: countries were called upon to take appropriate measures for the conservation of biodiversity and the sustainable use of its benefits. The Convention on Biological Diversity came from this summit.
The World Summit on Sustainable Development at Johannesburg, South Africa, in 2002: 190 countries pledged to achieve by 2010 a significant reduction in the current rate of biodiversity loss at global, regional and local levels.

NEET traps

1. Genetic vs species vs ecological diversity: Rauwolfia vomitoria and mango varieties are genetic; Western Ghats amphibians are species; deserts, rain forests and mangroves are ecological.
2. Z value: about 0.1 to 0.2 for areas within a region; 0.6 to 1.2 for continents. Do not swap them.
3. S, A, Z, C: S is species richness, A is area, Z is slope, C is the Y-intercept.
4. Rivet popper hypothesis is by Paul Ehrlich; the stability experiments are by Tilman; the species-area relationship is by Humboldt.
5. Extinct species: dodo (Mauritius), quagga (Africa), thylacine (Australia), Steller's sea cow (Russia). Do not mix up the places.
6. Nile perch went into Lake Victoria and led to the loss of cichlids; African catfish Clarias gariepinus threatens indigenous catfishes.
7. Over-exploitation vs habitat loss: habitat loss and fragmentation is the most important cause of biodiversity loss.
8. Hotspots in India: Western Ghats and Sri Lanka, Indo-Burma and Himalaya. Not the Eastern Ghats or the Thar desert.
9. In situ vs ex situ: sacred groves and national parks are in situ; zoos, botanical gardens, cryopreservation and seed banks are ex situ.
10. Rio 1992 vs Johannesburg 2002: the Earth Summit was at Rio; the pledge for reducing loss by 2010 was at Johannesburg.

One-liners

1. Edward Wilson popularised the term biodiversity.
2. India has about 8.1% of the global species diversity.
3. India is one of 12 megadiversity countries.
4. About 1.5 million species have been described; Robert May's estimate is about 7 million.
5. Species diversity is highest in the tropics and falls towards the poles.
6. Humboldt gave the species-area relationship: log S = log C + Z log A.
7. Z is about 0.1 to 0.2 in regions and 0.6 to 1.2 for continents.
8. Tilman found that more species give more stable and productive plots.
9. The rivet popper hypothesis is by Paul Ehrlich.
10. The dodo, quagga, thylacine and Steller's sea cow are extinct.
11. The evil quartet: habitat loss and fragmentation, over-exploitation, alien species invasions, co-extinctions.
12. Nile perch caused the extinction of more than 200 cichlid species in Lake Victoria.
13. There are 34 hotspots in the world; three cover India.
14. Cryopreservation stores gametes in liquid nitrogen at −196°C.
15. The Convention on Biological Diversity came from the Rio Earth Summit of 1992.

Practice questions

The term biodiversity was popularised by
1. Alexander von Humboldt
2. Edward Wilson
3. David Tilman
4. Paul Ehrlich
Answer
B. Edward Wilson
The sociobiologist Edward Wilson popularised the term biodiversity.
The variation in potency and concentration of reserpine in Rauwolfia vomitoria in different regions of the Himalayas is an example of
1. genetic diversity
2. alpha diversity of birds
3. ecological diversity
4. species diversity
Answer
A. genetic diversity
Variation within one species is genetic diversity.
The greater number of amphibian species in the Western Ghats than in the Eastern Ghats is an example of
1. co-extinction
2. genetic diversity
3. species diversity
4. ecological diversity
Answer
C. species diversity
Species diversity is the variety of species in a region.
India has about what share of the global species diversity?
1. 18.1%
2. 0.81%
3. 2.4%
4. 8.1%
Answer
D. 8.1%
India has about 2.4% of the world's land area but about 8.1% of the global species diversity.
India is one of how many megadiversity countries of the world?
1. 5
2. 34
3. 12
4. 20
Answer
C. 12
India is one of the 12 megadiversity countries.
Species diversity is generally highest in the
1. tropics near the equator
2. temperate regions
3. polar regions
4. regions near 41°N
Answer
A. tropics near the equator
Species richness falls as we move from the equator towards the poles.
The species-area relationship was described by
1. Edward Wilson
2. Paul Ehrlich
3. Robert May
4. Alexander von Humboldt
Answer
D. Alexander von Humboldt
Humboldt observed that species richness increases with area up to a limit.
In the equation log S = log C + Z log A, Z represents the
1. species richness
2. slope of the line
3. area
4. Y-intercept
Answer
B. slope of the line
S is species richness, A is area, C is the Y-intercept and Z is the slope.
For very large areas such as continents, the value of Z lies between
1. 0.1 and 0.2
2. 2 and 3
3. 0.01 and 0.02
4. 0.6 and 1.2
Answer
D. 0.6 and 1.2
Z is 0.1 to 0.2 for regions but much steeper, 0.6 to 1.2, for continents.
The rivet popper hypothesis was proposed by
1. Paul Ehrlich
2. Alexander von Humboldt
3. David Tilman
4. Edward Wilson
Answer
A. Paul Ehrlich
Ehrlich compared species to rivets that hold an aircraft together.
Which extinct animal was native to Mauritius?
1. Thylacine
2. Quagga
3. Dodo
4. Steller's sea cow
Answer
C. Dodo
The dodo is from Mauritius; the quagga is from Africa; the thylacine from Australia; Steller's sea cow from Russia.
The introduction of Nile perch into Lake Victoria led to the extinction of more than 200 species of
1. amphibians
2. cichlid fish
3. sea cows
4. gymnosperms
Answer
B. cichlid fish
The Nile perch is an alien predator that wiped out many native cichlids.
Which of the following is NOT one of the four causes called the evil quartet?
1. Over-exploitation
2. Co-extinctions
3. Seed banking
4. Habitat loss and fragmentation
Answer
C. Seed banking
Seed banking is an ex situ conservation method, not a cause of loss.
Which of the following biodiversity hotspots includes parts of India?
1. Tropical Andes
2. Cape Floristic Region
3. Madagascar
4. Indo-Burma
Answer
D. Indo-Burma
The three hotspots covering India are Western Ghats and Sri Lanka, Indo-Burma and Himalaya.
Which of the following is an ex situ conservation method?
1. National parks
2. Cryopreservation
3. Biosphere reserves
4. Sacred groves
Answer
B. Cryopreservation
Cryopreservation keeps gametes outside their natural habitat; the others are in situ.
The Earth Summit on biodiversity was held in 1992 at
1. Rio de Janeiro
2. Mauritius
3. Colombo
4. Johannesburg
Answer
A. Rio de Janeiro
The 1992 Earth Summit was at Rio de Janeiro; the 2002 World Summit was at Johannesburg.
Given below are two statements: Statement I: India has more than 50,000 genetically different strains of rice. Statement II: India has about 1,000 varieties of mango. Choose the correct answer.
1. Both Statement I and Statement II are correct
2. Both Statement I and Statement II are incorrect
3. Statement I is correct but Statement II is incorrect
4. Statement I is incorrect but Statement II is correct
Answer
A. Both Statement I and Statement II are correct
Both are examples of genetic diversity.
Given below are two statements: Statement I: In Tilman's long-term experiments, plots with more species showed less year-to-year variation in total biomass. Statement II: Species richness increases with area without any limit. Choose the correct answer.
1. Both Statement I and Statement II are correct
2. Both Statement I and Statement II are incorrect
3. Statement I is correct but Statement II is incorrect
4. Statement I is incorrect but Statement II is correct
Answer
C. Statement I is correct but Statement II is incorrect
Species richness increases with area only up to a limit.
Given below are two statements: Statement I: The value of Z is 0.6 to 1.2 for small areas within a region. Statement II: On a logarithmic scale the species-area relationship is a straight line. Choose the correct answer.
1. Both Statement I and Statement II are correct
2. Both Statement I and Statement II are incorrect
3. Statement I is correct but Statement II is incorrect
4. Statement I is incorrect but Statement II is correct
Answer
D. Statement I is incorrect but Statement II is correct
Z is 0.1 to 0.2 for regions and 0.6 to 1.2 for continents.
Given below are two statements: Statement I: The tropics are species-rich because they have been disturbed by frequent glaciations. Statement II: The tropical environment is highly seasonal and unpredictable. Choose the correct answer.
1. Both Statement I and Statement II are correct
2. Both Statement I and Statement II are incorrect
3. Statement I is correct but Statement II is incorrect
4. Statement I is incorrect but Statement II is correct
Answer
B. Both Statement I and Statement II are incorrect
Tropical latitudes were undisturbed for a long time and are less seasonal and more predictable.
Given below are two statements: Statement I: Habitat loss and fragmentation is the most important cause of biodiversity loss. Statement II: The African catfish Clarias gariepinus is a native species of Indian rivers. Choose the correct answer.
1. Both Statement I and Statement II are correct
2. Both Statement I and Statement II are incorrect
3. Statement I is correct but Statement II is incorrect
4. Statement I is incorrect but Statement II is correct
Answer
C. Statement I is correct but Statement II is incorrect
It was introduced for aquaculture and threatens indigenous catfishes.
Given below are two statements: Statement I: In situ conservation protects species outside their natural habitat. Statement II: Sacred groves are a form of in situ conservation. Choose the correct answer.
1. Both Statement I and Statement II are correct
2. Both Statement I and Statement II are incorrect
3. Statement I is correct but Statement II is incorrect
4. Statement I is incorrect but Statement II is correct
Answer
D. Statement I is incorrect but Statement II is correct
In situ means on site, in the natural habitat.
Given below are two statements: Statement I: Cryopreservation stores gametes of threatened species at very low temperature. Statement II: Seed banks store seeds of different genetic strains of crop plants. Choose the correct answer.
1. Both Statement I and Statement II are correct
2. Both Statement I and Statement II are incorrect
3. Statement I is correct but Statement II is incorrect
4. Statement I is incorrect but Statement II is correct
Answer
A. Both Statement I and Statement II are correct
Both are ex situ methods.
Given below are two statements: Statement I: Steller's sea cow was native to Africa. Statement II: The thylacine was native to Mauritius. Choose the correct answer.
1. Both Statement I and Statement II are correct
2. Both Statement I and Statement II are incorrect
3. Statement I is correct but Statement II is incorrect
4. Statement I is incorrect but Statement II is correct
Answer
B. Both Statement I and Statement II are incorrect
Steller's sea cow was from Russia and the thylacine from Australia.
Which of the following statements about biodiversity hotspots are correct? 1. They have a high degree of endemism. 2. They cover less than 2% of the earth's land area. 3. No hotspot covers any part of India.
1. 2 and 3 only
2. 1 and 2 only
3. 1 and 3 only
4. 1, 2 and 3
Answer
B. 1 and 2 only
Three hotspots cover India, so statement 3 is wrong.
Which of the following statements are correct? 1. Parthenium is an alien invasive weed. 2. The thylacine was native to Russia. 3. Lantana is an alien invasive weed.
1. 1 and 2 only
2. 2 and 3 only
3. 1, 2 and 3
4. 1 and 3 only
Answer
D. 1 and 3 only
The thylacine was native to Australia.
Assertion (A): Tropical areas support more species than temperate areas. Reason (R): The tropical environment is less seasonal and more constant and predictable.
1. Both A and R are true and R is the correct explanation of A
2. Both A and R are true but R is not the correct explanation of A
3. A is true but R is false
4. A is false but R is true
Answer
A. Both A and R are true and R is the correct explanation of A
A stable environment promotes niche specialisation and greater species diversity.
Assertion (A): Habitat loss and fragmentation is the most important cause of biodiversity loss. Reason (R): The Nile perch caused the extinction of many cichlid species in Lake Victoria.
1. Both A and R are true and R is the correct explanation of A
2. Both A and R are true but R is not the correct explanation of A
3. A is true but R is false
4. A is false but R is true
Answer
B. Both A and R are true but R is not the correct explanation of A
Both are true, but the Nile perch is an example of alien species invasion, not of habitat loss.
Assertion (A): Sacred groves are an example of in situ conservation. Reason (R): In sacred groves, gametes are stored in liquid nitrogen.
1. Both A and R are true and R is the correct explanation of A
2. Both A and R are true but R is not the correct explanation of A
3. A is true but R is false
4. A is false but R is true
Answer
C. A is true but R is false
Sacred groves protect species in their natural habitat; liquid nitrogen storage is cryopreservation.
Assertion (A): On an arithmetic scale the species-area relationship is a straight line. Reason (R): On a logarithmic scale the species-area relationship is a straight line.
1. Both A and R are true and R is the correct explanation of A
2. Both A and R are true but R is not the correct explanation of A
3. A is true but R is false
4. A is false but R is true
Answer
D. A is false but R is true
On an arithmetic scale it is a rectangular hyperbola.
Assertion (A): The extinction of a host species can cause the extinction of the parasites that depend on it. Reason (R): Co-extinction is the extinction of species associated in an obligatory way with another species that has become extinct.
1. Both A and R are true and R is the correct explanation of A
2. Both A and R are true but R is not the correct explanation of A
3. A is true but R is false
4. A is false but R is true
Answer
A. Both A and R are true and R is the correct explanation of A
A parasite dependent on a single host is lost with the host.
Assertion (A): Rauwolfia vomitoria is an example of genetic diversity. Reason (R): The Western Ghats have more amphibian species than the Eastern Ghats.
1. Both A and R are true and R is the correct explanation of A
2. Both A and R are true but R is not the correct explanation of A
3. A is true but R is false
4. A is false but R is true
Answer
B. Both A and R are true but R is not the correct explanation of A
Both are true, but the second is an example of species diversity and does not explain the first.
Match List I with List II. List I: a. Edward Wilson b. Alexander von Humboldt c. Paul Ehrlich d. David Tilman List II: i. Rivet popper hypothesis ii. Species-area relationship iii. Popularised the term biodiversity iv. Long-term experiments on plots with different species richness Choose the correct answer.
1. a-iii, b-ii, c-iv, d-i
2. a-i, b-ii, c-iv, d-iii
3. a-iii, b-ii, c-i, d-iv
4. a-ii, b-iii, c-i, d-iv
Answer
C. a-iii, b-ii, c-i, d-iv
Each scientist is matched with the work described.
Match List I with List II. List I: a. Dodo b. Quagga c. Thylacine d. Steller's sea cow List II: i. Australia ii. Russia iii. Mauritius iv. Africa Choose the correct answer.
1. a-iii, b-iv, c-i, d-ii
2. a-i, b-iii, c-iv, d-ii
3. a-iii, b-ii, c-i, d-iv
4. a-ii, b-iv, c-i, d-iii
Answer
A. a-iii, b-iv, c-i, d-ii
Dodo - Mauritius, quagga - Africa, thylacine - Australia, Steller's sea cow - Russia.
Match List I with List II. List I: a. Nile perch b. Parthenium c. Water hyacinth d. Clarias gariepinus List II: i. Eichhornia ii. Carrot grass iii. Extinction of cichlids in Lake Victoria iv. African catfish introduced for aquaculture Choose the correct answer.
1. a-ii, b-iii, c-i, d-iv
2. a-i, b-ii, c-iv, d-iii
3. a-iii, b-ii, c-i, d-iv
4. a-iii, b-ii, c-iv, d-i
Answer
C. a-iii, b-ii, c-i, d-iv
Each alien species is matched with its name or its effect.
Match List I with List II. List I: a. Biodiversity hotspot b. Sacred grove c. Cryopreservation d. Seed bank List II: i. Gametes stored in liquid nitrogen ii. Seeds of genetic strains stored iii. Forest patch protected on religious grounds iv. Region of high endemism under threat from habitat loss Choose the correct answer.
1. a-iv, b-i, c-iii, d-ii
2. a-i, b-iii, c-ii, d-iv
3. a-ii, b-iii, c-i, d-iv
4. a-iv, b-iii, c-i, d-ii
Answer
D. a-iv, b-iii, c-i, d-ii
Hotspot - high endemism; sacred grove - religious protection; cryopreservation - liquid nitrogen; seed bank - seeds.
Match List I with List II. List I: a. Colombia near the equator b. New York at 41°N c. Greenland at 71°N d. India List II: i. About 105 bird species ii. About 56 bird species iii. More than 1,200 bird species iv. About 1,400 bird species Choose the correct answer.
1. a-i, b-ii, c-iv, d-iii
2. a-iv, b-i, c-ii, d-iii
3. a-iv, b-i, c-iii, d-ii
4. a-ii, b-i, c-iv, d-iii
Answer
B. a-iv, b-i, c-ii, d-iii
Bird species fall from the equator towards the poles.
Match List I with List II. List I: a. Rio Earth Summit 1992 b. Johannesburg Summit 2002 c. Z in the species-area equation d. Number of biodiversity hotspots in the world List II: i. 34 ii. Slope of the line iii. Pledge to reduce the rate of biodiversity loss by 2010 iv. Convention on Biological Diversity Choose the correct answer.
1. a-i, b-iii, c-iv, d-ii
2. a-ii, b-iii, c-iv, d-i
3. a-iv, b-iii, c-ii, d-i
4. a-iv, b-i, c-ii, d-iii
Answer
C. a-iv, b-iii, c-ii, d-i
Rio gave the Convention on Biological Diversity; Johannesburg gave the 2010 pledge; Z is the slope; there are 34 hotspots.
A study of birds in a region finds that the slope Z of the log S against log A line is 0.15. This value is
1. typical of whole continents
2. impossible for any group
3. within the usual range of 0.1 to 0.2 for areas within a region
4. typical only of plants
Answer
C. within the usual range of 0.1 to 0.2 for areas within a region
Z is about 0.1 to 0.2 regardless of taxonomic group for areas within a region.
A village community protects a forest patch where no tree may be cut because of religious belief. This is
1. ex situ conservation
2. cryopreservation
3. seed banking
4. in situ conservation
Answer
D. in situ conservation
Sacred groves protect species in their natural habitat.
Sperm of a threatened animal is stored at −196 °C in liquid nitrogen. This is an example of
1. ex situ conservation
2. a biosphere reserve
3. a sacred grove
4. in situ conservation
Answer
A. ex situ conservation
Cryopreservation is an ex situ method.
A weed brought from another continent spreads over farmland and replaces native plants. This is an example of
1. over-exploitation
2. alien species invasion
3. habitat fragmentation
4. co-extinction
Answer
B. alien species invasion
Parthenium, Lantana and water hyacinth are invasive alien species.
A plant is pollinated only by one species of insect. That insect becomes extinct. The plant is most likely to
1. become extinct as well, as an example of co-extinction
2. remain unaffected
3. be conserved in situ automatically
4. become an invasive alien species
Answer
A. become extinct as well, as an example of co-extinction
Species associated in an obligatory way go extinct together.
An agency has limited funds and wants to protect the largest number of endemic species threatened by habitat loss. The best strategy is
1. to set up a botanical garden of common species
2. to introduce alien fish into lakes
3. to ban all travel to tropical regions
4. to protect biodiversity hotspots
Answer
D. to protect biodiversity hotspots
Hotspots have high endemism and are under threat, and cover less than 2% of the land area.
Two sets of grassland plots are followed for many years: one with 2 species and another with 20 species. Which is expected for the species-rich plots?
1. No change in any parameter
2. Less year-to-year variation in total biomass
3. Lower productivity
4. More year-to-year variation in total biomass
Answer
B. Less year-to-year variation in total biomass
Tilman's experiments showed more stable and more productive plots with more species.

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