AP BIOLOGY

Detailed explanation-1: -Radiant energy or solar energy and fixed energy, which living organisms can use, are the two types of energy flow.

Detailed explanation-2: -The double channel or Y-Shaped energy flow model depicts the simultaneous working of grazing and detritus food chains in an ecosystem. In nature, both grazing and detritus food chains are inter-connected in the same ecosystem.

Detailed explanation-3: -An energy pyramid is a model that shows the flow of energy from one trophic, or feeding, level to the next in an ecosystem. The model is a diagram that compares the energy used by organisms at each trophic level.

Detailed explanation-4: -There are two types of food chains: the grazing food chain, beginning with autotrophs, and the detrital food chain, beginning with dead organic matter (Smith & Smith 2009).