You will write a two-paragraph summary of how photosynthesis and cell respiration are related. In your first paragraph address the cycling of matter--be specific! How does one process provide the raw materials for the other and vice versa? In your second paragraph, discuss the flow of energy that takes place in an ecosystem. Be sure to discuss the initial energy source as well as the role of photosynthesis and cell respiration. Notice that respiration is not an entirely efficient process and some of the energy produced is lost as heat. Address the need for continual energy input to the ecosystem. This is not a cycle!