Question

how do energy and matter move through an ecosystem?
energy unidirectionally flows through an ecosystem, whereas matter generally cycles within an ecosystem.
matter unidirectionally flows through an ecosystem, whereas energy cycles within an ecosystem.
both energy and matter unidirectionally flow through an ecosystem.
both energy and matter cycle within an ecosystem.

Explanation:

In ecosystems, energy enters as sunlight, moves up trophic levels, and is lost as heat, so it has a one-way (unidirectional) flow. Matter (like carbon, nitrogen) is reused and recycled between organisms and the physical environment, forming closed cycles.

Answer:

Energy unidirectionally flows through an ecosystem, whereas matter generally cycles within an ecosystem.