The dramatic increase in the population of Nile perch in Lake Victoria was due to:

1.	floods	2.	eutrophication
3.	drought	4.	the introduction of new food

Migratory birds like Siberian cranes are facing threats of extinction mainly due to:
1. pesticides
2. fragmentation or loss of habitat
3. urbanization
4. bad weather

The peregrine falcon in the United States got extinct due to:

The most recorded extinctions during the past 500 years have occurred among:
1. flowering plants
2. mammals
3. birds
4. amphibians

The species that are vulnerable to extinction do not include the species that:
1. have high genetic variability
2. are hunted or harvested by people
3. have a declining population size
4. are local endemic species

The current extinction is called a ‘biodiversity crisis’ because:
1. the extinctions are not a natural phenomenon
2. the rates are high and is due to the human activities
3. the extinction is mainly affecting animals rather than plants
4. only keystone species are being lost

An endangered species as compared to a threatened species:
1. is nearer to extinction
2. threatens the survival of other species
3. is one about which the known data is deficient
4. has more diversity

Apex predators also commonly act as:

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: