Assertion (A): | Certain exotic species, introduced into a geographical area, become invasive. |
Reason (R): | The exotic species that become invasive can only be plants that can reproduce asexually very rapidly. |
In the light of the above statements, choose the most appropriate answer from the options given below :
1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | (A) is false but (R) is true. |
The high level of species diversity of the tropics can be due to all of the following except:
1. | predictability | 2. | predation |
3. | spatial homogeneity | 4. | high productivity |
The most important cause of the loss of biodiversity today is the:
1. Habitat loss and fragmentation
2. Overexploitation
3. Alien species invasion
4. Co-extinctions
Introduction of Lates niloticus led to the extinction of:
1. | Gambusia | 2. | Pupfish |
3. | Cichlid fish | 4. | Chinook salmon |
Year-to-year variation shown by areas with more species is ................... with respect to areas with less species.
1. | less | 2. | more |
3. | same | 4. | absent |
The total number of biodiversity hotspots in the world is:
1. | 25 | 2. | 17 |
3. | 34 | 4. | 51 |
Between community, diversity is known as:
1. | alpha diversity | 2. | beta diversity |
3. | gamma diversity | 4. | delta diversity |
Which of the following is a source of an antimalarial drug?
1. | Papaver somniferum | 2. | Cinchona officinalis |
3. | Artemesia species | 4. | Both 2 and 3 |
A plant, that has invaded many forest lands in India and is also known as Spanish Flag or Red sage, is:
1. | Lantana camara | 2. | Eicchornia |
3. | Parthenium argentatum | 4. | Argemone mexicana |
Which of the following characteristics does not make a species vulnerable to extinction?
1. a large body size
2. small population size and low reproductive rates
3. feeding at a lower trophic level in the food chain
4. fixed migratory route and habitat