Question

Assertion (A): The energy which passes to the herbivores does not come back to autotrophs. Reason (R): The flow of energy in a food chain is unidirectional.

Assertion : Greater number of individuals are present in lower trophic levels. Reason : The flow of energy is unidirectional

Green plants capture about 1% of the solar energy incident on the earth to carry out the process of photosynthesis. A part of this trapped energy is used by plants in performing their metabolic activities and some energy is released as heat into the atmosphere. When these green plants are eaten up by herbivores, the chemical energy stored in the plants is transferred to these animals. These animals (herbivores) utilise some of this energy for metabolic activities and some energy is released as heat while the remaining energy is stored in their body. This process of energy transfer is repeated till top carnivores. In an ecosystem, transfer of energy follows 10 percent law, i.e,, only 10 percent of the energy is transferred to each trophic level from the lower trophic level.

Give reasons for the following :