At each level of the food chain, what happens to about 90% of the energy? A) gained as energy B) lost as heat C) converted into unusable compounds D) excreted as waste
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. A food chain can usually sustain no more than six energy transfers before all the energy is used up.
