Question

On an average, the proportion of assimilated energy consumed by herbivores in respiration is
A. $10\% $
B. $20\% $
C. $30\% $
D. $60\% $

Answer 1

Hint: In respiration, the energy absorbed by the herbivores is used and a portion of the energy not assimilated is passed to decomposers. This energy is passed through the food chain to distinct trophic stages. The energy flow occurs through the food chain as well as the food web.

Complete answer:
First we should know about energy flow to answer this question. One of the key reasons promoting the survival of such a vast number of species is the energy flow in the environment. The chemical energy in food is the primary energy source needed by all life forms.
Now, let us find the solution from the options-
The demise of herbivores, the herbivorous energy level is then used by carnivores or passed to decomposers. Again just a small fraction, around $10\% $ of herbivore productivity, is used to enhance carnivore productivity. Thus, option A is not the correct option.
Similarly, the energy required at the trophic stage of the carnivore is broken again, leaving a very small fraction to sustain the next trophic level, that is, the top level of the carnivore. The cost of ventilation also rises dramatically with rising trophic speeds. Producers, on average, use approximately $20\% $ of their total breathing productivity. Thus, option B is not the correct option.
Around 30 percent of the assimilated energy absorbed in respiration is consumed by herbivores, rising to about $60\% $ . Thus at successively greater trophic speeds, there is a considerable lack of resources.
In breathing, significant amounts of assimilated energy are used. $30\% $ of assimilated energy is used for respiration in herbivores. Herbivores are more effective than animals at using resources for their growth and production. Plants, however, grow more rapidly than mammals. Thus, option D is not the correct option.
So, the correct answer is “Option C”.

Note:
The main source of energy is solar energy for nearly all life on earth. It is surprising to note that less than $50\% $ of the effective energy of the sun on earth is obtained from humans. When we say that radiation is efficient, we think radiation that can be used by plants to perform photosynthesis.