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:
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:
1. | less plants in fragmented habitats leads to less photosynthesis. |
2. | more soil erosion takes place in fragmented habitats. |
3. | smaller populations in fragmented habitats are more prone to extinction. |
4. | animals migrate out of smaller habitat fragments. |
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.
1. | Only I and II | 2. | Only I and III |
3. | Only II and III | 4. | I, II and III |
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
Plants are an important source of medicines for human use. Identify the incorrectly matched pair:
|
PLANT |
MEDICINE |
1. |
Taxusbrevifolia |
Anticancer drug |
2. |
Cinchona officinalis |
Anti-malarial |
3. |
Rauwolfiaserpentina |
Anti-hypertensive |
4. |
Catharanthusroseus |
Anti-helminthic |
The type of species that will most likely be supported by small parks will be:
1. | k - selected species | 2. | r - selected species |
3. | climax species | 4. | species with small niches |
Which of the following is a biocide that was first to be used on a large scale?
1. | DDT | 2. | 2,4-D |
3. | Mercury | 4. | Methane |