Q. No.To recycle nutrients, an ecosystem must have, at a minimum,
1. producers.
2. producers and decomposers.
3. producers, primary consumers, and decomposers.
4. producers, primary consumers, secondary consumers, and decomposers.
1. producers.
2. producers and decomposers.
3. producers, primary consumers, and decomposers.
4. producers, primary consumers, secondary consumers, and decomposers.
1. community, ecosystem, individual, population
2. ecosystem, community, population, individual
3. population, ecosystem, individual, community
4. individual, population, community, ecosystem
Assertion: In a food chain, members of successive higher levels are fewer in number.
Reason: Number of organisms at any trophic level depends upon the availability of organisms which serve as food at the lower level.
1. Both Assertion & Reason are true and Reason is the correct explanation of Assertion
2. Both Assertion & Reason are true but Reason is not the correct explanation of Assertion
3. Assertion is true statement but Reason is false.
4. Both Assertion and Reason are false statements.
- If both the assertion and the reason are true and the reason is a correct explanation of the assertion
- If both the assertion and reason are true but the reason is not a correct explanation of the assertion
- If the assertion is true but the reason is false
- If both the assertion and reason are false
| 1. | They recycle chemical elements directly back to primary consumers |
| 2. | They synthesize organic molecules that are used by primary producers |
| 3. | They convert organic materials from all trophic levels to inorganic compounds usable by primary producers |
| 4. | They secrete enzymes that convert the organic molecules of detritus into CO2 and H2O |
1. NPP can be expressed in energy/unit of area/unit of time
2. NPP can be expressed in terms of carbon fixed by photosynthesis for an entire ecosystem
3. NPP represents the stored chemical energy that is available to consumers in the ecosystem
4. NPP is the same as the standing crop
Why is net primary production (NPP) a more useful measurement to an ecosystem ecologist than gross primary productivity (GPP)?
1. NPP can be expressed in energy/unit of area/unit of time.
2. NPP can be expressed in terms of carbon fixed by photosynthesis for an entire ecosystem.
3. NPP represents the stored chemical energy that is available to consumers in the ecosystem.
4. NPP is the same as the standing crop
| Assertion (A): | Energy flow in ecosystem is bidirectional. |
| Reason (R): | Energy goes on increasing with each and every trophic level. |
| 1. | Both (A) and (R) are True and (R) correctly explains (A). |
| 2. | Both (A) and (R) are True but (R) does not correctly explain (A). |
| 3. | (A) is True but (R) is False. |
| 4. | Both (A) and (R) are False. |
1. Low stability and high resilience
2. High stability and low resilience
3. High stability and high resilience
4. Low stability and low resilience
A. Removal of 80% tigers from an area resulted in increased growth of vetetation
B. Removal of most of the carnivores resulted in increased growth of vegetation
C. The length of food chain is generally limited to 3-4 tropic levels due to energy loss
D. The length of food chains may vary from 208 trophic levels
Choose the correct answer from the options given below:
1. A, D
2. A, B
3. B, C
4. C, D
1. 2-10%
2. 50%
3. 100%
4. 1-2%
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