Q. No.Carbon dioxide is returned to the atmosphere by all the following except:
1. photosynthesis by the primary producers
2. respiratory activities of producers and consumers
3. decomposers
4. volcanic activity
1. photosynthesis by the primary producers
2. respiratory activities of producers and consumers
3. decomposers
4. volcanic activity
Deforestation has affected the carbon cycle primarily by:
| 1. | decreasing the amount of carbon available for photosynthesis |
| 2. | increasing the rate of release of carbon dioxide into the atmosphere |
| 3. | preventing the loss of fixed carbon to sediments |
| 4. | reducing the decomposition of organic matter by microbes |
Regarding phosphorus cycle:
| I: | There is no respiratory release of phosphorus into atmosphere |
| II: | Atmospheric inputs of phosphorus through rainfall of phosphorus is small |
1. Only I is true.
2. Only II is true.
3. Both I and II are true.
4. Both I and II are false.
What is common to Pantoeaagglomerans, Microbacteriumlaevaniformans and Pseudomonas putida?
1. They are phosphate solubilising bacteria
2. They are all denitrifiers
3. They are genetically modified to fix atmospheric nitrogen
4. They are source of antibiotics effective against MRSA
The price tag put by researchers on the annual ecosystem services is about:
1. USD 11 trillion
2. USD 22 trillion
3. USD 33 trillion
4. USD 44 trillion
Identify the incorrectly matched pair:
|
Ecosystem service |
Cost out of total [%] |
|
|
1. |
Soil formation |
50 |
|
2. |
Nutrient cycling |
10 |
|
3. |
Climate regulation |
6 |
|
4. |
Habitat for wildlife |
3 |
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 |
A chemical that enters living organisms primarily from the atmosphere is:
| 1. | phosphorus | 2. | sulfur |
| 3. | sodium | 4. | carbon |
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. |
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