Energy roles in the environment 7.EC.5B.2 Develop and use models (food webs and energy pyramids) to exemplify how the transfer of energy in an ecosystem supports the concept that energy is conserved.

Flow of energy All organisms have energy roles in their environments. Each role is determined by how the organism obtains its energy and how they interact with other organisms in the environment. The flow of energy in an environment can be represented using the following diagrams: Food webs Energy pyramids

Food webs A food web describes the organisms in a particular ecosystem found in interconnecting food chains using pictures or words and arrows. Food webs describe the complex patterns of energy flow in an ecosystem by modeling who consumes whom or what.

Energy pyramids An energy pyramid is a graphical representation of the energy flow in an ecosystem. The amount of energy that moves from one trophic level to another in an energy pyramid is not the same. Energy availability decreases as it moves up the energy pyramid. The most energy is available at the producer level of the pyramid.