Which of the following type of ecosystem is expected in an area where evaporation exceeds precipitation, and mean annual rainfall is below 100 mm?
1. Grassland
2. Shrubby forest
3. Desert
4. Mangrove
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): | 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): | 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. |