Q. No.What would be true for the phosphorus cycle in an ecological ecosystem?
1.
A considerable amount of phosphorus enters the biosphere through the primary producers.
2.
Fossil fuels represent the major reservoir of phosphorus.
3.
Phosphorus cycling occurs through the atmosphere, ocean, and through living and dead organisms.
4.
There is no respiratory release of phosphorus into the atmosphere.
| 1. | begins with primary producers like grass |
| 2. | is the major conduit for energy flow in an aquatic ecosystem |
| 3. | is not made up of any decomposers |
| 4. | may be connected with the grazing food chain at some levels |
| I. | The change in communities during ecological succession is orderly and sequential, parallel with the changes in the physical environment. |
| II. | Secondary succession is faster than primary succession. |
| III. | Usually, lichens are pioneer species during primary xerarch succession. |
| 1. | Only I |
| 2. | Only II |
| 3. | Both I and III |
| 4. | I, II and III |
| Statement I: | Decomposition is a process in which the detritus is degraded into simpler substances by microbes. |
| Statement II: | Decomposition is faster if the detritus is rich in lignin and chitin. |
In light of the above statements, choose the correct answer from the options given below:
| 1. | Statement I is incorrect but Statement II is correct. |
| 2. | Both Statement I and Statement II are correct. |
| 3. | Both Statement I and Statement II are incorrect. |
| 4. | Statement I is correct but Statement II is incorrect. |
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. 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.
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