Q. No.The annual net primary productivity of whole biosphere is approximately:
1. 25 billion tons 2. 55 billion tons 3. 70 billion tons 4. 170 billion tons
By process of leaching during decomposition of detritus, water soluble :
| 1. | organic nutrients go down the soil horizon and get precipitated as available salts |
| 2. | inorganic nutrients go down the soil horizon and get precipitated as unavailable salts |
| 3. | organic nutrients go down the soil horizon and get precipitated as available salts |
| 4. | inorganic nutrients go down the soil horizon and get precipitated as available salts |
The three steps of decomposition occur:
1. sequentially, with catabolism being the last step.
2. sequentially, with leaching being the last step.
3. simultaneously.
4. sequentially, but not in a particular order.
Decomposition of detritus is rapid when:
1. It is rich in lignin and chitin
2. Ambient temperature is low
3. Environment favours anaerobiosis
4. It predominantly contains nitrogen and sugars
What percentage of photosynthetic active radiation is captured by plants?
| 1. | 1 – 5 | 2. | 2 – 10 |
| 3. | 50 | 4. | 90 |
Primary carnivores are, most aptly, characterized as:
| 1. | Secondary producers | 2. | Primary consumers |
| 3. | Secondary consumers | 4. | Tertiary consumers |
In a terrestrial ecosystem, a much larger fraction of energy flows through the:
| 1. | DFC | 2. | GFC |
| 3. | Either of DFC or GFC | 4. | Nither of DFC nor GFC |
In an aquatic food chain, zooplankton occupy which trophic level?
| 1. | First | 2. | Second |
| 3. | Third | 4. | Fourth |
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 |
Approximately, what percent of energy is transferred to each trophic level from the lower trophic level in an ecosystem?
| 1. | 1 | 2. | 10 |
| 3. | 50 | 4. | 90 |
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