Question

the flow of materials in ecosystem is cyclic but the flow of energy is unidirectional. explain

Answer 1

The flow of energy in the ecosystem is unidirectional. The energy enters the plants (from the sun) through photosynthesis during the making of food. This energy is then passed on from one organism to another in a food chain

Also, the nutrient movement is a cyclic movement where the nutrients revolve round with an ecosystem, hence cyclic. Nutrients pass from abiotic nutrient stores, such as the soil and the atmosphere, into biotic, plant and animal stores (the biomass). The nutrients are then recycled, within the ecosystem, following death and decomposition

Answer 2

Flow of energy is unidirectional because

according to 10% law, 10% of energy is transferred to the succeeding trophic level.

And the energy cannot get reversed or cannot be acquired by the previous trophic level.

hope it helps.