NEET Biology Biodiversity and Conservation MCQs Set 12

Answer: (c) a (iv), b (iii), c (ii), d (i)

Explanation:
1. Ants are more than 20,000 species, beetles more than 300,000, fishes more than 28,000 and orchids about 20,000.

Teacher's Note:
1. Biodiversity exists at genetic, species and ecosystem levels; about 1.5 million species have been described, and Robert May's global estimate is about 7 million.
2. Species richness increases from poles to equator and decreases with altitude; the species-area relationship is a rectangular hyperbola that becomes a straight line on a log scale, log S = log C + Z log A.

Answer: (a) Edward Wilson

Explanation:
1. The term biodiversity was popularised by the sociobiologist Edward Wilson.

Teacher's Note:
1. In situ conservation includes biosphere reserves, national parks, sanctuaries and sacred groves; ex situ includes zoos, botanical gardens and gene banks.
2. Biodiversity hotspots are chosen by high species richness, high endemism and high habitat loss; India has three (Western Ghats-Sri Lanka, Indo-Burma, Himalaya).

Answer: (c) >50.000 and 1.000 respectively

Explanation:
1. India has more than 50,000 genetically different strains of rice and about 1,000 varieties of mango.

Teacher's Note:
1. Biodiversity exists at genetic, species and ecosystem levels; about 1.5 million species have been described, and Robert May's global estimate is about 7 million.
2. Species richness increases from poles to equator and decreases with altitude; the species-area relationship is a rectangular hyperbola that becomes a straight line on a log scale, log S = log C + Z log A.

Answer: (b) A single species cannot show more diversity at genetic level

Explanation:
1. A single species can show great genetic diversity (rice, for example), so statement 2 is incorrect.

Teacher's Note:
1. The evil quartet of biodiversity loss: habitat loss and fragmentation, over-exploitation, alien species invasion and co-extinction.
2. David Tilman showed that more species give more stability; Paul Ehrlich proposed the rivet popper hypothesis.

Answer: (b) Bio chemical or molecular method

Explanation:
1. Biochemical or molecular methods are considered best for estimating microbial diversity.

Teacher's Note:
1. Biodiversity exists at genetic, species and ecosystem levels; about 1.5 million species have been described, and Robert May's global estimate is about 7 million.
2. Species richness increases from poles to equator and decreases with altitude; the species-area relationship is a rectangular hyperbola that becomes a straight line on a log scale, log S = log C + Z log A.

Answer: (c) According to Robert May's global estimate only 22% of the total species have been recorded so for

Explanation:
1. Robert May estimated that only about 22 per cent of total species have been recorded so far.

Teacher's Note:
1. In situ conservation includes biosphere reserves, national parks, sanctuaries and sacred groves; ex situ includes zoos, botanical gardens and gene banks.
2. Biodiversity hotspots are chosen by high species richness, high endemism and high habitat loss; India has three (Western Ghats-Sri Lanka, Indo-Burma, Himalaya).

Answer: (d) All of these

Explanation:
1. Latitudinal and altitudinal gradients and species-area relationships all shape biodiversity patterns.

Teacher's Note:
1. Biodiversity exists at genetic, species and ecosystem levels; about 1.5 million species have been described, and Robert May's global estimate is about 7 million.
2. Species richness increases from poles to equator and decreases with altitude; the species-area relationship is a rectangular hyperbola that becomes a straight line on a log scale, log S = log C + Z log A.

Answer: (c) Straight line

Explanation:
1. On a logarithmic scale the species-area relationship is a straight line.

Teacher's Note:
1. Biodiversity exists at genetic, species and ecosystem levels; about 1.5 million species have been described, and Robert May's global estimate is about 7 million.
2. Species richness increases from poles to equator and decreases with altitude; the species-area relationship is a rectangular hyperbola that becomes a straight line on a log scale, log S = log C + Z log A.

Answer: (c) Regression coefficient

Explanation:
1. In log S = log C + Z log A, Z is the slope of the line (regression coefficient).

Teacher's Note:
1. The evil quartet of biodiversity loss: habitat loss and fragmentation, over-exploitation, alien species invasion and co-extinction.
2. David Tilman showed that more species give more stability; Paul Ehrlich proposed the rivet popper hypothesis.

Answer: (c) 1.15

Explanation:
1. For frugivorous birds and mammals in tropical forests the slope Z is about 1.15, steeper than usual.

Teacher's Note:
1. In situ conservation includes biosphere reserves, national parks, sanctuaries and sacred groves; ex situ includes zoos, botanical gardens and gene banks.
2. Biodiversity hotspots are chosen by high species richness, high endemism and high habitat loss; India has three (Western Ghats-Sri Lanka, Indo-Burma, Himalaya).

Answer: (a) David Tilman

Explanation:
1. David Tilman's long term experiments showed that plots with more species had less year to year variation in biomass.

Teacher's Note:
1. Biodiversity exists at genetic, species and ecosystem levels; about 1.5 million species have been described, and Robert May's global estimate is about 7 million.
2. Species richness increases from poles to equator and decreases with altitude; the species-area relationship is a rectangular hyperbola that becomes a straight line on a log scale, log S = log C + Z log A.

Answer: (d) Amphibians

Explanation:
1. Amphibians appear more vulnerable to extinction than other groups.

Teacher's Note:
1. Biodiversity exists at genetic, species and ecosystem levels; about 1.5 million species have been described, and Robert May's global estimate is about 7 million.
2. Species richness increases from poles to equator and decreases with altitude; the species-area relationship is a rectangular hyperbola that becomes a straight line on a log scale, log S = log C + Z log A.

Answer: (a) 100

Explanation:
1. Ecologists warn that nearly half of the species on earth may be wiped out within the next 100 years.

Teacher's Note:
1. The evil quartet of biodiversity loss: habitat loss and fragmentation, over-exploitation, alien species invasion and co-extinction.
2. David Tilman showed that more species give more stability; Paul Ehrlich proposed the rivet popper hypothesis.

Answer: (c) Constant pest and disease cycles

Explanation:
1. Loss of biodiversity leads to variability in pest and disease cycles, not constant cycles.

Teacher's Note:
1. In situ conservation includes biosphere reserves, national parks, sanctuaries and sacred groves; ex situ includes zoos, botanical gardens and gene banks.
2. Biodiversity hotspots are chosen by high species richness, high endemism and high habitat loss; India has three (Western Ghats-Sri Lanka, Indo-Burma, Himalaya).

Answer: (a) Habitat loss and fragmentation

Explanation:
1. Habitat loss and fragmentation is the most important cause of biodiversity loss.

Teacher's Note:
1. Biodiversity exists at genetic, species and ecosystem levels; about 1.5 million species have been described, and Robert May's global estimate is about 7 million.
2. Species richness increases from poles to equator and decreases with altitude; the species-area relationship is a rectangular hyperbola that becomes a straight line on a log scale, log S = log C + Z log A.

Answer: (b) 6%

Explanation:
1. Tropical rain forests once covered over 14 per cent of the land but now cover no more than about 6 per cent.

Teacher's Note:
1. The evil quartet of biodiversity loss: habitat loss and fragmentation, over-exploitation, alien species invasion and co-extinction.
2. David Tilman showed that more species give more stability; Paul Ehrlich proposed the rivet popper hypothesis.

Answer: (d) Both (1) and (2)

Explanation:
1. The Amazon rain forest is cleared for soybean cultivation and for grasslands to raise beef cattle.

Teacher's Note:
1. In situ conservation includes biosphere reserves, national parks, sanctuaries and sacred groves; ex situ includes zoos, botanical gardens and gene banks.
2. Biodiversity hotspots are chosen by high species richness, high endemism and high habitat loss; India has three (Western Ghats-Sri Lanka, Indo-Burma, Himalaya).

Answer: (d) Both (1) and (2)

Explanation:
1. Fragmentation affects mammals and birds needing large territories and migratory animals.

Teacher's Note:
1. Biodiversity exists at genetic, species and ecosystem levels; about 1.5 million species have been described, and Robert May's global estimate is about 7 million.
2. Species richness increases from poles to equator and decreases with altitude; the species-area relationship is a rectangular hyperbola that becomes a straight line on a log scale, log S = log C + Z log A.

Answer: (a) Cichlid fish

Explanation:
1. Introduction of the Nile perch in Lake Victoria led to the extinction of more than 200 species of cichlid fish.

Teacher's Note:
1. The evil quartet of biodiversity loss: habitat loss and fragmentation, over-exploitation, alien species invasion and co-extinction.
2. David Tilman showed that more species give more stability; Paul Ehrlich proposed the rivet popper hypothesis.

Answer: (d) All of the above

Explanation:
1. Hotspots are selected on high species richness, high endemism and a high degree of habitat loss.

Teacher's Note:
1. Biodiversity exists at genetic, species and ecosystem levels; about 1.5 million species have been described, and Robert May's global estimate is about 7 million.
2. Species richness increases from poles to equator and decreases with altitude; the species-area relationship is a rectangular hyperbola that becomes a straight line on a log scale, log S = log C + Z log A.

Answer: (b) National parks – 85

Explanation:
1. India has about 90 national parks, not 85.

Teacher's Note:
1. In situ conservation includes biosphere reserves, national parks, sanctuaries and sacred groves; ex situ includes zoos, botanical gardens and gene banks.
2. Biodiversity hotspots are chosen by high species richness, high endemism and high habitat loss; India has three (Western Ghats-Sri Lanka, Indo-Burma, Himalaya).