Which of the following statements about productivity is true ?

Options

A. Primary productivity of all ecosystems is constant
B. Annual net primary productivity of the whole of the biosphere is 170 billion tons (dry weight) of organic matter.
C. Gross primary productivity is the amount of biomass available for consumption to carnivores
D. Primary productivity depends upon the animal species inhabiting a particular area.

Answer

B

Explanation

Primary productivity varies in different type of ecosystem.
Annal net primary productivity of the whole of the biosphere is 170 billion tons (dry weight of organic matter
Net primary productivity is the amount of biomass available for consumption to heterotrophs (herbivoures and decomposers).