| 1. | They recycle chemical elements directly back to primary consumers |
| 2. | They synthesize organic molecules that are used by primary producers |
| 3. | They convert organic materials from all trophic levels to inorganic compounds usable by primary producers |
| 4. | They secrete enzymes that convert the organic molecules of detritus into CO2 and H2O |
Why is net primary production (NPP) a more useful measurement to an ecosystem ecologist than gross primary productivity (GPP)?
1. NPP can be expressed in energy/unit of area/unit of time.
2. NPP can be expressed in terms of carbon fixed by photosynthesis for an entire ecosystem.
3. NPP represents the stored chemical energy that is available to consumers in the ecosystem.
4. NPP is the same as the standing crop
| Assertion (A): | Energy flow in ecosystem is bidirectional. |
| Reason (R): | Energy goes on increasing with each and every trophic level. |
| 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 but (R) is False. |
| 4. | Both (A) and (R) are False. |