AP BIOLOGY

Detailed explanation-1: -The amount of energy at each trophic level decreases as it moves through an ecosystem. As little as 10 percent of the energy at any trophic level is transferred to the next level; the rest is lost largely through metabolic processes as heat.

Detailed explanation-2: -Energy decreases as it moves up trophic levels because energy is lost as metabolic heat when the organisms from one trophic level are consumed by organisms from the next level. Trophic level transfer efficiency (TLTE) measures the amount of energy that is transferred between trophic levels.

Detailed explanation-3: -As you move up the pyramid, through the trophic levels to primary, secondary and tertiary consumers, the amount of energy decreases and the levels become smaller. While energy can not be created or destroyed is it released as heat within each level. Approximately only 10% of energy is passed from one level to the next.

Detailed explanation-4: -On average, only about 10 percent of energy stored as biomass in a trophic level is passed from one level to the next. This is known as “the 10 percent rule” and it limits the number of trophic levels an ecosystem can support.

Detailed explanation-5: -The ten percent rule states that each trophic level can only give 10% of its energy to the next level. The other 90% is used to live, grow, reproduce and is lost to the environment as heat. All energy pyramids start with energy from the Sun which is transferred to the first trophic level of producers.