Assertion (A): | Secondary succession is usually faster than primary succession. |
Reason (R): | Secondary succession is a process started by an event that reduces an already established ecosystem. |
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): | Lichens are commonly the pioneer species during primary succession on rocks. |
Reason (R): | Lichens are able to secrete acids to dissolve rocks. |
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): | Low temperature and anaerobiosis inhibit decomposition resulting in build-up of organic chemicals. |
Reason (R): | Most decomposers are anaerobic psychrophiles. |
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. |
Sometimes the term "detritivore" is used interchangeably with:
1. | decomposers | 2. | primary consumers |
3. | secondary consumers | 4. | autotrophs |
The minimum requirement for an ecosystem to recycle nutrients present in it would be:
1. | producers |
2. | producers and decomposers |
3. | producers, primary consumers, and decomposers |
4. | producers, primary consumers, secondary consumers, and decomposers |
Net primary productivity is the gross primary productivity minus:
1. | that which is consumed by herbivores |
2. | that which is consumed by the producer in metabolism |
3. | secondary productivity |
4. | loss due to mortality |
Most organic material is converted to carbon dioxide, which can then be utilized in primary production by:
1. autotrophs
2. secondary consumers
3. herbivores
4. carnivores
The best way to describe an ecosystem would be that they are:
1. | processors of energy and transformers of matter. |
2. | processors of matter and transformers of energy. |
3. | processors of matter and energy. |
4. | transformers of matter but not of energy. |
The amount of carbon dioxide in the atmosphere is:
1. increasing
2. decreasing
3. holding steady
4. fluctuating wildly
The ecosystem that can survive in the absence of the Sun would be:
1. | tropical rainforest | 2. | tundra |
3. | benthic ocean | 4. | desert |