Question

The rate at which light energy is converted into chemical energy of organic molecules is

• A. Net primary productivity
• B. Gross secondary productivity
• C. Net secondary productivity
• D. Gross primary productivity

Answer 1

The correct option is D Gross primary productivity

The rate of biomass production is called as productivity. It is expressed in terms of grams per year or kcal per square meter per year. To compare the productivity of different ecosystems, productivity 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, i.e., the rate at which light energy is converted into chemical energy. A considerable amount of GPP is utilised by plants in respiration. Gross primary productivity minus respiration losses (R), is the net primary productivity (NPP).