The correct option that completes the statement in the right order is:
photosynthesis; respiration; heat
Thus, the full statement would read: "Chemical energy input converted from the sun occurs via photosynthesis in plants or ingesting food in animals; this energy drives the flow of matter into and out of the cell. The chemical energy is inefficiently converted into usable energy by respiration, because all the stored energy is not converted into ATP, some of it is released into the ecosystem as heat."