| I: | Energy flow in an ecosystem is unidirectional. |
| II: | Energy once lost as heat can be recycled within the ecosystem. |
Each trophic level has a certain mass of living material at a particular time, best called as:
| 1. | Biomass | 2. | Standing state |
| 3. | Standing crop | 4. | Gross productivity |
| I: | It begins with dead organic matter. |
| II: | It is the major conduit for energy flow in aquatic ecosystem. |
| III: | It is not connected with the grazing food chain at any level. |
| 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 |
| Assertion (A): | In a food chain, man is considered as an apex predator and a top consumer. |
| Reason (R): | In a food chain, man is placed at the top and has no known natural predators. |
| 1. | Both (A) and (R) are True and (R) correctly explains (A) |
| 2. | Both (A) and (R) are True and (R) does not correctly explain (A) |
| 3. | (A) is True, (R) is False |
| 4. | (A) is False, (R) is False |
| 1. | herbaceous and woody plants. | 2. | phytoplankton |
| 3. | algae | 4. | mosses |
| Assertion (A): | Organisms at each trophic level depend on those at the lower trophic level for their energy demands. |
| Reason (R): | The amount of energy decreases at successive trophic levels. |
| 1. | Both (A) and (R) are True and (R) correctly explains (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). |
| 1. | Spirogyra | 2. | Agaricus |
| 3. | Volvox | 4. | Nostoc |
The producers in aquatic ecosystems include all except:
| 1. | cyanobacteria | 2. | algae |
| 3. | plants | 4. | zooplankton |