Which one of the following will accelerate phosphorus cycle?
1. Rainfall and storms
2. Burning of fossil fuels
3. Volcanic activity
4. Weathering of rocks
1. Rainfall and storms
2. Burning of fossil fuels
3. Volcanic activity
4. Weathering of rocks
| 1. Decomposition | 2. Catabolism |
| 3. Fragmentation | 4. Humification |
Identify the correct set of statements with regard to the properties of humus.
| (a) | Highly resistant to microbial action |
| (b) | Dark-colored amorphous substance |
| (c) | End product of detritus food chain |
| (d) | Reservoir of nutrients |
| (e) | Undergoes decomposition very fast |
Choose the correct answer from the options given below:
1. (a), (b), and (d) only
2. (a),(b) and (e) only
3. (a) and (b) only
4. (b), (c), and (a)
Which of the following is not correct regarding the decomposition of wastes?
| (a) | Low temperature inhibits decomposition |
| (b) | Warm and moist environment favors the process |
| (c) | The process is anaerobic |
| (d) | It is slower if detritus is rich in proteins and carbohydrates |
| (e) | Detritus is degraded into simpler inorganic substance by fungal and bacterial enzymes |
Choose the correct answer from the options given below:
| 1. | (b) and (c) only | 2. | (c), (a) and (d) only |
| 3. | (c) and (d) only | 4. | (c), (d) and (e) only |
Given below are two statements:
| Statement I: | Pyramid of energy is always upright and is the most efficient. |
| Statement II: | Pyramid of biomass in sea is generally inverted. |
In the light of the above statements, choose the most appropriate answer from the options given below:
1. Statement I is correct but Statement II is incorrect.
2. Statement I is incorrect but Statement II is correct.
3. Both Statement I and Statement II are correct.
4. Both Statement I and Statement II are incorrect.
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. 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
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