| A: | Detrivores perform fragmentation. |
| B: | The humus is further degraded by some microbes during mineralization. |
| C: | Water soluble inorganic nutrients go down into the soil and get precipitated by a process called leaching. |
| D: | The detritus food chain begins with living organisms. |
| E: | Earthworms break down detritus into smaller particles by a process called catabolism. |
| 1. | D, E, A only | 2. | A, B, C only |
| 3. | B, C, D only | 4. | C, D, E only |
| List - I | List - II | ||
| (A) | Hydrarch succession | (I) | Gradual change in the species composition |
| (B) | Xerarch succession | (II) | Faster and climax reached quickly |
| (C) | Ecological succession | (III) | Lichens to mesic conditions |
| (D) | Secondary succession | (IV) | Phytoplankton to mesic conditions |
| Options: | (A) | (B) | (C) | (D) |
| 1. | IV | II | III | I |
| 2. | III | I | IV | II |
| 3. | I | IV | II | III |
| 4. | IV | III | I | II |
| 1. | Standing state | 2. | Standing crop |
| 3. | Humus | 4. | Detritus |
| 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.