Assertion (A): | Large islands near the mainland will have more species than smaller islands more distant from the mainland. |
Reason (R): | The species richness of an island is determined by colonization and extinction. |
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. | Both (A) and (R) are false. |
Assertion (A): | Endemic organisms with limited ranges are most affected by habitat destruction. |
Reason (R): | These organisms are not found anywhere else in the world, and thus have less chance of recovering. |
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. | Both (A) and (R) are false. |
Assertion (A): | Pollution may cause extinction debt - future extinction of species due to events in the past. |
Reason (R): | Extinction debt occurs because of time delays between impacts on a species, such as destruction of habitat, and the species' ultimate disappearance. |
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. | Both (A) and (R) are false. |
Assertion (A): | The indirect effects of losing many species as well as the diversity of ecosystems in general are enormous. |
Reason (R): | When biodiversity is lost, the environment loses many species that perform valuable and unique roles in the ecosystem. |
1. | Both (A) and (R)are true and (R) is the correct explanation of the (A). |
2. | Both(A) and (R) are true but (R) is not the correct explanation of the (A). |
3. | (A) is true but (R) is false. |
4. | Both (A) and (R) are false. |
Assertion (A): | Intermediate frequency or intensity of disturbance in a biological community will maximize diversity. |
Reason (R): | Only at intermediate levels of disturbance do a mix of colonizers and competitors co-exist. |
1. | Both (A) and (R) are true and (R) is the correct explanation of the (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. | Both (A) and (R) are false. |
Assertion (A): | If introduced species evolved under great competition or predation in their native habitat, they are more likely to become invasive in the introduced habitat. |
Reason (R): | Then the new environment may host fewer able competitors, allowing the invader to proliferate quickly. |
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 reason are true but (R) is not the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | Both (A) and (R) are false. |
Assertion (A): | Island ecosystems are generally more prone to invasion by the introduced species. |
Reason (R): | Invasion is more likely in ecosystems that was similar to the one in which the potential invader evolved. |
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. | Both (A) and (R) are false. |
.
Assertion (A): | Animals like elephants and whales are highly prone to extinction due to over-exploitation. |
Reason (R): | Large-body-sized animals with low rates of reproduction makes them more susceptible to extinction. |
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. | Both (A) and (R) are false. |
When the habitat gets fragmented, the edge effect:
1. | increases | 2. | decreases |
3. | remains the same | 4. | is irrelevant |
The best preservation areas are:
1. small in size but multiple in number
2. large ones are better than small-sized ones
3. the size is less important than the number
4. size and number are irrelevant