NEET Biology Biodiversity and Conservation MCQs Set 13

Answer: (d) All of the above

Explanation:
1. Biodiversity exists at genetic, species and ecosystem levels.
2. So all the options are correct.

Teacher's Note:
1. The three are basic levels of biodiversity.

Answer: (a) Edward Wilson

Explanation:
1. Sociobiologist Edward Wilson popularised the term biodiversity.
2. Tilman and Ehrlich proposed hypotheses about stability and rivet popping.

Teacher's Note:
1. He is known for sociobiology.

Answer: (c) More than 50000 and 1000

Explanation:
1. India has more than 50000 genetically different strains of rice.
2. It also has 1000 varieties of mango.

Teacher's Note:
1. It is an example of genetic diversity.

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

Explanation:
1. A single species can show high genetic diversity, like medicinal plant Rauwolfia vomitoria varying in potency and concentration of the active chemical reserpine.
2. So statement (b) is wrong.

Teacher's Note:
1. Genetic variation within species is real.

Answer: (b) Biochemical or molecular method

Explanation:
1. Most microbes cannot be cultured in the laboratory.
2. So biochemical or molecular methods are used to estimate their diversity.

Teacher's Note:
1. The number of microbial species is poorly known.

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

Explanation:
1. Only about 22 percent of the estimated species have been recorded.
2. India has 8.1 percent species diversity and is one of 12 megadiversity countries.

Teacher's Note:
1. Much biodiversity remains undiscovered.

Answer: (b) Biodiversity increases from low altitude to high altitude

Explanation:
1. Biodiversity generally declines with increasing altitude.
2. So (b) is incorrect.

Teacher's Note:
1. Latitudinal gradient shows increase towards the equator.

Answer: (c) Straight line

Explanation:
1. On a log scale the relationship is a straight line described by log S = log C + Z log A.
2. On an arithmetic scale it is a rectangular hyperbola.

Teacher's Note:
1. Alexander von Humboldt observed the relationship.

Answer: (c) Regression coefficient

Explanation:
1. Z is the slope of the line, the regression coefficient.
2. S is species richness, A is area and C is the Y-intercept.

Teacher's Note:
1. Z lies between 0.1 and 0.2 for most regions.

Answer: (a) David Tilman

Explanation:
1. David Tilman's long-term field experiments showed that plots with more species had less year to year variation in biomass.
2. This supports the biodiversity-stability view.

Teacher's Note:
1. Ehrlich proposed the rivet popper hypothesis.

Answer: (c) Paul Ehrlich

Explanation:
1. Paul Ehrlich proposed the rivet popper hypothesis.
2. Species in an ecosystem are like rivets in an airplane, and losing some rivets may eventually cause a crash.

Teacher's Note:
1. It is an analogy about extinction.

Answer: (d) Prokaryotes - 2001

Explanation:
1. IUCN 2004 lists 359 invertebrates, 338 vertebrates and 87 plants as extinct in the last 500 years.
2. Prokaryotes are not given as 2001, so it is a wrong match.

Teacher's Note:
1. Total extinctions are 784.

Answer: (d) Amphibians

Explanation:
1. Amphibians appear more vulnerable to extinction.
2. More than 70 percent of the recorded amphibian species are in danger.

Teacher's Note:
1. Careful analysis of records shows non-random extinction.

Answer: (c) Constant pest and disease cycles

Explanation:
1. Loss of biodiversity leads to decline in plant production, lowered resistance to perturbations and increased variability.
2. It does not give constant pest and disease cycles.

Teacher's Note:
1. Stability depends on species richness.

Answer: (a) Habitat loss and fragmentation

Explanation:
1. Habitat loss and fragmentation is the most important cause of biodiversity loss.
2. The other three are also members of the evil quartet.

Teacher's Note:
1. Tropical rain forests are an example.

Answer: (d) Both soyabean cultivation and cattle grazing

Explanation:
1. Amazon forests are cleared to plant soyabeans and to make grasslands for beef cattle.
2. So (d) is correct.

Teacher's Note:
1. The Amazon harbours millions of species.

Answer: (d) Both mammals and birds requiring large territories and animals with migratory habits

Explanation:
1. Fragmentation affects mammals and birds that need large territories and migratory animals.
2. So option (d) is the best answer.

Teacher's Note:
1. Fragmentation causes population decline.

Answer: (a) Cichlid fish

Explanation:
1. Nile perch eliminated more than 200 species of cichlid fish in Lake Victoria.
2. It is an example of alien species invasion.

Teacher's Note:
1. Lake Victoria had a rich cichlid diversity.

Answer: (c) Clarias gariepinus

Explanation:
1. The African catfish Clarias gariepinus was illegally introduced for aquaculture.
2. It is a threat to the indigenous catfishes.

Teacher's Note:
1. It is an alien species.

Answer: (c) Drugs and medicines from plants

Explanation:
1. Biodiversity gives direct economic benefits like food, fibre and medicines.
2. Oxygen production, pollination and soil formation are ecosystem services.

Teacher's Note:
1. Over 25 percent of drugs come from plants.

Answer: (d) Gangetic plains

Explanation:
1. The three Indian hotspots are Western Ghats and Sri Lanka, Indo-Burma and Himalaya.
2. Gangetic plains are not a hotspot.

Teacher's Note:
1. India has a share of these hotspots.

Answer: (c) Sarguja, Chanda and Bastar areas - Mizoram

Explanation:
1. Sarguja, Chanda and Bastar areas are in Madhya Pradesh (now Chhattisgarh), not Mizoram.
2. The other places are correct.

Teacher's Note:
1. Sacred groves are protected by tradition.