Question

The amount of energy captured by photosynthesis, minus the amount of energy lost as heat in respiration, is:
A. Secondary productivity
B. Consumption efficiency
C. NPP
D. Photosynthetic efficiency

Answer 1

Hint: All plants and certain microorganisms such as algae, planktons etc. produce their own food with the help of sunlight and water. Photosynthesis is a process in which energy is utilized while respiration is a process in which energy is released usually in the form of heat.

Complete step by step solution:
Photosynthesis is an energy consuming process while respiration is an energy producing process. An autotrophic organism experiences loss of energy in between photosynthesis and respiration processes as these are important metabolic processes.

The amount of energy produced by the organisms in an ecosystem is called its productivity. Primary productivity is referred to as the amount of biomass generated by producers and thus, secondary productivity refers to the amount of biomass generated by primary consumers who feed on producers.

Consumption efficiency is a concept of energy obtained by the organisms from the available resources. It drives the theories of survival in nature. At the same time, Photosynthetic efficiency refers to the average rate of light energy being converted into chemical energy during the photosynthetic process by plants and other autotrophs.

NPP stands for net primary production. It is the amount of energy retained in the ecosystem. It does not include energy lost during metabolic processes but only the remaining energy that will be used by the organisms.

Thus, the amount of energy captured minus the energy lost as heat in metabolic processes is NPP or net primary production. So the correct answer is option C.

Note: During metabolic processes energy is lost in the form of heat and that energy is not included in the calculation of net primary production. The amount of energy that results in NPP is simply energy obtained in gross primary production minus the energy lost in respiration.