| 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. |
| 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.
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.