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 :

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?

Organisms that are capable of conversion of inorganic material into organic material with the help of the radiant energy of the sun include:

Primary carnivores are, most aptly, characterized as:

The detritus food chain:

1. Only I is correct
2. Only II is correct
3. Both I and II are correct
4. Both I and II are incorrect