Question

The biomass available for consumption to heterotrophs and the rate of formation of new organic matter by consumers are defined as

• A. Gross primary productivity and net primary productivity respectively
• B. Net primary productivity and gross primary productivity respectively
• C. Gross primary productivity and secondary productivity respectively
• D. Net primary productivity and secondary productivity respectively
• E. Secondary productivity and net primary productivity respectively

Answer 1

Answer: (D)

The rate of biomass production is called productivity. It can be divided into gross primary productivity (GPP) and net primary productivity (NPP). Gross primary productivity of an ecosystem is the rate of production of organic matter during photosynthesis. A considerable amount of GPP is utilised by plants in respiration. Net primary productivity is the available biomass for the consumption to heterotrophs (herbivores and decomposers). Secondary productivity is defined as the rate of formation of new organic matter by consumers.