Ecosystems and Biodiversity Questions and Answers

Answer: B

Hotspots are regions of endemism.

Norman Myers, who proposed biodiversity hotspots in 1988, and Conservation International define a hotspot by two criteria: it must hold at least 1,500 endemic species of vascular plants (species found nowhere else), and it must have lost at least 70% of its original vegetation. Endemism is thus the defining feature; the Western Ghats and the Himalaya are Indian examples.

Hotspots are rich in species, but high diversity alone does not qualify a region. Rarity and endangered species are consequences or concerns of conservation, not the criterion used to identify hotspots.

Answer: D

The process is succession.

Ecological succession is the orderly, directional replacement of one community by another in an area over time: pioneer species colonise, alter the conditions, and are replaced by later species through a sequence of seral stages until a relatively stable climax community is reached, as when bare rock passes through lichens and mosses to forest.

'Community change' is too vague and need not be directional. Competition is an interaction between species that can drive succession but is not the process itself, and climate change is a change in the physical environment, not species replacement.

Answer: A

The pond ecosystem has an inverted pyramid of biomass.

The producers in a pond are mostly phytoplankton: tiny organisms that reproduce very quickly but have a small standing crop at any moment. The zooplankton and fish that feed on them live longer and accumulate more biomass, so the standing biomass of consumers can exceed that of producers, and the pyramid of biomass is inverted, as in the open sea.

The pyramid of numbers in a pond is upright, since phytoplankton are far more numerous than fish, and a pyramid of energy can never be inverted, because energy is lost as heat at every transfer.

Answer: D

The key's answer is Hailey, the name under which the park was established.

India's first national park was created in 1936 in the United Provinces as Hailey National Park, named after the governor Sir Malcolm Hailey. After independence it was renamed Ramganga National Park, and in 1956-57 it was renamed again as Corbett National Park in memory of Jim Corbett.

Jim Corbett is therefore the same park under its later name; the question asks for the name of the park established in 1936, which was Hailey. Kaziranga became a national park only in 1974 and Ranthambore in 1980.

Answer: B

The one that is not an ex-situ strategy is National Park.

Ex-situ conservation protects species outside their natural habitats: in botanical gardens, zoos, seed banks, gene banks and tissue culture collections. These are the other three options.

A national park protects wild species in their natural habitat, together with the ecosystem they live in, so it is an in-situ method, along with wildlife sanctuaries and biosphere reserves.

Answer: C

The largest reservoir of carbon among these is the oceans.

The oceans hold roughly 38,000 billion tonnes of carbon, mostly as dissolved inorganic carbon (bicarbonate and carbonate) in the deep water. That is about fifty times the carbon in the atmosphere and far more than in all land vegetation. They also take up about a quarter of the CO₂ released by human activity each year, which makes them the main potential sink as well. (Sedimentary rocks hold more still, but they are not among the options.)

Forests and agricultural fields hold hundreds of billions of tonnes, and the atmosphere about 800 billion tonnes, each far less than the oceans.

Answer: B

On the key's reading, the Nilgiri tahr is confined to Eravikulam National Park, Kerala.

The Nilgiri tahr is a wild goat endemic to the high montane grasslands of the southern Western Ghats in Kerala and Tamil Nadu. Eravikulam National Park in Munnar was created to protect it and holds its largest population. (Smaller herds also live in nearby ranges such as the Anamalai and the Nilgiris, so 'only confined' is a simplification.)

Sasan Gir is the home of the Asiatic lion. Tadoba in Maharashtra and Bandhavgarh in Madhya Pradesh are tiger reserves in the dry deciduous forests of central India, far outside the tahr's range.