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

(N/A) The flow of energy in an ecosystem follows the path: $\text{Sun} \to \text{Producer} \to \text{Herbivore} \to \text{Carnivore}$.
This flow is considered unidirectional because energy is transferred from one trophic level to the next and cannot revert to the previous level.
Justification: According to the $10\%$ law of energy transfer,a significant amount of energy is lost as heat at each trophic level. Because the energy available at higher trophic levels is much lower than at lower levels,the energy cannot flow backward from a higher trophic level to a lower one.