Q. No.The nutrients in an ecosystem are:
1.
continuously lost from an ecosystem
2.
needed as a continuous supply from the outside
3.
recycled time and again indefinitely
4.
continuously synthesized by physical forces
The earth is regarded as “open” system with respect to:
| 1. | organisms | 2. | chemicals |
| 3. | energy | 4. | water |
If decomposers go extinct on Earth:
| 1. | Detritivores will replace them |
| 2. | Primary production will increase |
| 3. | Nutrients will accumulate in dead plants and animals |
| 4. | There will be no effect on carnivores |
What is the best description of trophic efficiency?
| 1. | the ratio of net secondary production to the assimilation of primary production. |
| 2. | the percentage of production transferred from one trophic level to the next. |
| 3. | a measure of how nutrients are cycled from one trophic level to the next. |
| 4. | usually greater than production efficiencies. |
What percent of the energy fixed by primary producers in a typical field ecosystem is received by a secondary consumer?
| 1. | 0.1% | 2. | 1% |
| 3. | 10% | 4. | 20% |
The residual, after autotrophic respiration is subtracted from GPP, is:
| 1. | secondary productivity | 2. | net primary productivity |
| 3. | standing crop biomass | 4. | chemosynthesis |
The producers in aquatic ecosystems include all except:
| 1. | cyanobacteria | 2. | algae |
| 3. | plants | 4. | zooplankton |
Which of the following is most likely to exhibit the maximum difference between GPP and NPP?
1. phytoplankton in the ocean.
2. corn plants in a farmerʹs field.
3. prairie grasses.
4. an oak tree in a forest.
Primary producers near deep-sea vents are:
1. Chemohetrotrophic prokaryotes
2. Chemoauotrophic prokaryotes
3. Photosynthetic prokaryotes
4. Photosynthetic autotrophs
Decomposers like fungi and bacteria are :
| i. | Autotrophs |
| ii. | Heterotrophs |
| iii. | Saptrotrophs |
| iv. | Chemo-autotrophs |
Choose the correct answer :
| 1. | i and ii | 2. | i and iv |
| 3. | ii and iii | 4. | i and iii |
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