| Assertion (A): | Heterotrophs generally have high energy conversion efficiencies when compared to those of plants. |
| Reason (R): | At higher trophic levels, the respiratory costs are dramatically reduced. |
| 1. | (A) is True but (R) is False |
| 2. | Both (A) and (R) are True and (R) correctly explains (R) |
| 3. | Both (A) and (R) are True but (R) does not correctly explain (A) |
| 4. | Both (A) and (R) are False |
Consider the two given statements:
| Assertion (A): | Secondary succession is faster than the primary succession. |
| Reason (R): | Soil is already there at the time of secondary succession. |
| 1. | Both (A) and (R) are True and (R) correctly explains the (A) |
| 2. | (A) is True but (R) is False |
| 3. | (A) is False but (R) is True |
| 4. | Both (A) and (R) are True but (R) does not correctly explain (A) |
| 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 |
| Assertion (A): | Lichens are the first organisms to colonise bare rocks hence are ecologically important |
| Reason (R): | Lichens are symbiotic association between two heterotrophs |
| 1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
| 2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
| 3. | (A) is true but (R) is false. |
| 4. | Both (A) and (R) are false. |
| Assertion (A): | No energy that is trapped into an organism remains in it for ever. |
| Reason (R): | The energy trapped by producers is either passed on to a consumer or the organism dies. |
| 1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
| 2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
| 3. | (A) is true but (R) is false. |
| 4. | Both (A) and (R) are false. |
| Assertion (A): | Pyramid of energy is always upright, can never be inverted. |
| Reason (R): | When energy flows from a particular trophic level to the next trophic level, some energy is always lost as heat at each step. |
| 1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
| 2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
| 3. | (A) is true but (R) is false. |
| 4. | Both (A) and (R) are false. |