Discuss the path and directional flow of energy

The flow of energy in the ecosystem is generally unidirectional and there is loss of energy across each trophic levels successively.

Explanation:

The entry of energy occurs in the form of sunlight which is process by the plant through photosynthesis resulting in formation of nutrient essential for survival of plants. This plant energy then moves to the living organism feeding on it such as primary consumer. Here most of energy is used up and some energy is lost as heat. Likewise in the case of secondary consumers and tertiary consumers energy is used up with loss of some energy as heat at each level. The energy flow is unidirectional in the sense that it cannot be used back by the plant from the consumer levels. Thus the energy flows successively with loss at each level as heat.