question_answer 47)

  Indicate the flow of energy in an ecosystem. Why is it unidirectional? Justify.

Answer:

                    The flow of energy in an ecosystem occurs in following sequence The flow of energy is unidirectional because of reasons given below (i) Energy flows progressively from one trophic level to another and cannot revert back. Energy given out as heat is lost in the environment, it does not return to be used again (ii) Also, the available energy decreases at higher trophic level. Out of the total energy available , at a particular trophic level, only 10% is passed on to the next trophic level, making it impossible for energy to flow in the reverse direction.