Energy in Ecosystems

• Food webs show all of the feeding interactions between producers and consumers within an ecosystem.
• Energy flows from the grass to the mouse when the mouse eats the grass.
• Food chains show simple feeding relationships that exist in an ecosystem.
• Energy is passed from one organism to the next in a food chain.
• Most energy is lost as it is transferred from one level to the next in a food chain.
• Energy is lost as heat, movement, and undigested materials in a food chain.
• Only a small quantity of the energy taken in is used and so is available at the next level in a food chain.
• This energy is used for growth in a food chain.
• Each organism gets less energy as it moves up a food chain.
• A pyramid of numbers is a diagram that shows the total number of organisms at each level of a food chain.
• An irregular pyramid of numbers is a diagram that shows the total number of organisms at each level of a food chain.
• A pyramid of energy shows the energy available at each stage in a food chain (kJ/m2/year).