| I: | The trophic level of an organism is the position it occupies in a food web. |
| II: | The trophic level represents species and not a functional level. |
| III: | A given organism occupies only one trophic level in a food chain. |
| IV: | The trophic level of an organism is the number of steps it is from the start of the chain. |
| 1. | Population | 2. | Biological community |
| 3. | Ecosystem | 4. | Biome |
| I: | consumes plants. |
| II: | is also called as secondary consumer. |
| I: | They do not take into account the same species belonging to two or more trophic levels. |
| II: | They do not accommodate a food web. |
| Assertion (A): | Earthworm is considered as enemy of farmers. |
| Reason (R): | They loosen off the soil. |
| 1. | Both (A) and (R) are True and (R) correctly explains (A) |
| 2. | Both (A) and (R) are True but (R) does not correctly explain (A) |
| 3. | (A) is True, (R) is False |
| 4. | (A) is False, (R) is True |
| Assertion (A): | Ecosystems are exempt from the second law of thermodynamics. |
| Reason (R): | Ecosystems do not require a constant supply of energy. |
| 1. | Both (A) and (R) are True and (R) correctly explains (A) |
| 2. | Both (A) and (R) are True but (R) does not correctly explain (A) |
| 3. | (A) is True, (R) is False |
| 4. | (A) is False, (R) is False |
| Statement I: | In a particular climatic condition, decomposition rate is quicker if detritus is rich in lignin and chitin, and slower, if detritus is rich in nitrogen and water-soluble substances like sugars. |
| Statement II: | Warm and moist environment favour decomposition whereas low temperature and anaerobiosis inhibit decomposition. |