Apex predators also commonly act as:

1.	Keystone species	2.	Tertiary consumers
3.	Endemic species	4.	Ecospecies

The most serious negative impact of loss of biodiversity on humans would be due to:
1. global warming and ozone depletion.
2. loss of ecosystem services.
3. loss of source of genetic diversity to preserve endangered species.
4. loss of species for ʺbioprospecting.ʺ

Habitat loss and fragmentation lead to loss of biodiversity primarily because:

Exotic alien introduced species can become invasive in the introduced ecosystem due to:
I. preying on native species.
II. out-competing native species for food, light, and breeding habitat.
III. lack of natural predators.

Overexploitation is one of the “evil quartet” that increases the risk of extinction mainly for the:
1. animals that feed on a lower trophic level
2. large animals with low intrinsic reproductive rates
3. aquatic animals
4. terrestrial organisms

The biggest factor for the ‘biodiversity crisis' that we face today is:
1. Global warming
2. Environmental pollution
3. Habitat loss and fragmentation
4. A large and increasing human population

Consider three sample areas with the following composition: 

Which area will be considered as the most diverse?
1. Sample area I
2. Sample area II
3. Sample area III
4. Sample area II and Sample area III are equally diverse

Regarding the gradients of biodiversity:

1. Only I is correct
2. Only II is correct
3. Both I and II are correct
4. Both I and II are incorrect

Plants are an important source of medicines for human use. Identify the incorrectly matched pair:

The pink headed duck has got extinct mainly due to:
1. Habitat destruction
2. Overexploitation
3. Alien invasion
4. Pollution