How much of the net primary productivity of a terrestrial ecosystem is eaten and digested by herbivores?
1. | 1% | 2. | 10% |
3. | 40% | 4. | 90% |
The zone at the edge of a lake or ocean which is alternatively exposed to air and immersed in water is called?
1. | Pelagic zone | 2. | Benthic zone |
3. | Lentic zone | 4. | Littoral zone |
Which of the following is an ecosystem service provided by a natural ecosystem?
1. | Cycling of nutrients |
2. | Prevention of soil erosion |
3. | Pollutant absorption and reduction of the threat of global warming |
4. | All of the above |
Assertion (A): | Various adaptations have evolved in plants that can increase their uptake of nutrients. |
Reason (R): | Plants are unable to ‘choose’ their environment as they are unable to move about. |
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): | Most of an ecosystem’s production is eventually consumed by detritivores and decomposers. |
Reason (R): | Energy is said to flow through, not cycle within, 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): | 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): | 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): | 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 (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. |