Secondary productivity is defined with respect to-
a. Producers
b. Consumers
c. Ratio of producers and consumers
d. Trophic level

Primary productivity of an terrestrial ecosystem depends upon
a. Photosynthetic capacity of plants.
b. A variety of environmental factors,
c. Availability of nutrients
d. All of the above.

What is the annual net primary productivity of the whole biosphere
a. 160 billion tons
b. 170 billion tons
c. 177 billion tons
d. 190 billion tons

Which of the following contributes the maximum to the net primary productivity?
a. Ocean ecosystem
b. Land ecosystem
c. Pond ecosystem
d. Man-made ecosystem

Why do we call the earthworm as the farmer’s friend?
a. It eats the pests
b. It prevents the growth of weeds
c. Makes the soil fertile by burrowing
d. They help in the breakdown of complex organic matter as well as in loosening of the soil.

Which of the following is not a step in the process of decomposition?
a. Fragmentation
b. Leaching
c. Anabolism
d. Humification.

Which of the following statement is correct?
a. Dead plant and animals remains, including fecal matter, constitute detritus,
b. Detritus is the product of decomposition.
c. Breakdown of complex inorganic matter into organic substances like CO₂ and nutrients is called as decomposition.
d. Decomposition is a single step process.

Identify the correct order of steps in decomposition.
a. fragmentation, catabolism, leaching, humification and
mineralisation
b. fragmentation, humification, catabolism and
mineralisation
c. fragmentation, leaching, catabolism, humification and
mineralisation
d. fragmentation, leaching, catabolism, mineralisation
and humification.

What is the process by which Detritivores break down the detritus into smaller particles.?
a. Degradation
b. Decomposition
c. Fragmentation
d. Leaching

What does the process of leaching refers to-
a. Accumulation of a dark coloured amorphous substance
B. Organic solvents reabsorbed by the plants
c. Inorganic solvents get precipitated out of the soil
d. Water soluble inorganic nutrients go down into the soil horizon and get precipitated as unavailable salts.