Question

Please explain the idea that energy flows through a biological system, while nutrients cycle, with a description of one relevant example for each.

Answer 1

Energy and nutrients, or chemicals,flow through an ecosystem. While energy flows through the ecosystem and cannot be recycled, nutrients cycle within an ecosystem and are reused. Both energy flow and chemical cycling help define the structure and dynamics of the ecosystem.

Example is food chain: At each stage of a food chain, energy is “burned” for an organism's respiration and lost to heat, so decreasing amounts are available to consumers at higher trophic levels. A standard approximation is that a mere 10 percent of the energy stored at one trophic level passes to the next one up.