In an ecosystem, the rate of production of organic matter during photosynthesis is called as its:
1. | Gross Primary productivity |
2. | Net Primary productivity |
3. | Secondary productivity |
4. | Non productivity |
The rate of formation of new organic matter by consumers in an ecosystem is known as:
1. | Gross Primary productivity |
2. | Net Primary productivity |
3. | Secondary productivity |
4. | Non-productivity |
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 |
During decomposition of detritus, the step that is performed by bacteria and fungi includes:
1. Catabolism only
2. Catabolism and fragmentation
3. Leaching and catabolism
4. Fragmentation, Leaching and Catabolism
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.
Humus:
1. Is easily broken down by microbes
2. Undergoes decomposition rapidly
3. Serves as a reservoir of nutrients
4. Yields organic nutrients on mineralization
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 |
Organisms that are capable of conversion of inorganic material into organic material with the help of the radiant energy of the sun include:
I: | Plants |
II: | Photosynthetic bacteria |
III: | Chemosynthetic bacteria |
1. | I only | 2. | I and II only |
3. | I and III only | 4. | I, II, and III |