Assertion (A): | Most food chains or webs have only about four or five trophic levels. |
Reason (R): | Trophic efficiencies are generally only about 10% in different ecosystems. |
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): | Of all the required nutrients other than nitrogen, phosphorus is the most likely to be scarce enough to limit plant growth. |
Reason (R): | The reservoir of phosphorus is in the mineral form rather than in the atmosphere. |
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): | Net primary productivity is higher in warm climates than in cold ones. |
Reason (R): | The limit on a community’s productivity is determined ultimately by the amount of sunlight it receives. |
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): | Some aquatic ecosystems have inverted biomass pyramids. |
Reason (R): | The pyramid of energy is also inverted in such ecosystems. |
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: Ecosystems with intermediate levels of productivity tend to have the most species.
Reason: The relationship between productivity and species richness is not linear.
1. Both assertion and reason are true and the reason is the correct explanation of the assertion.
2. Both assertion and reason are true but the reason is not the correct explanation of the assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false
Assertion (A): | Saprophytes play a vital role in the ecosystem. |
Reason (R): | Saprophytes are accorded the highest trophic level in a food chain or a food web. |
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): | There is no limitation on the number of trophic levels in a detritus food chain. |
Reason (R): | The transfer of energy between successive trophic levels in a detritus food chain does not follow the 10% rule. |
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: The Amazon basin exhibits especially high productivity from roughly August through October - the period of the area's dry season.
Reason: Even in the tropics, there are variations in productivity over the course of the year.
1. Both assertion and reason are true and the reason is the correct explanation of the assertion.
2. Both assertion and reason are true but the reason is not the correct explanation of the assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false
Assertion (A): | Strongly vertically stratified habitats are very stable ecosystems. |
Reason (R): | Through the formation of different layers a given habitat is better utilized. |
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): | Carnivores generally have higher assimilation efficiencies than herbivores. |
Reason (R): | Carnivores generally consume more food than herbivores. |
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. |