Question

Which statement best explains why less energy is available to organisms as a food chain gets longer?

Answer 1

The food chain is a cycle of energy. The energy and biomass successively decrease along the food chain as animals from higher trophic levels consume the animals from lower trophic levels. As each animal consumes the other, only 10% is transferred to the next organism

Answer 2

This is due to much of the energy that is consumed by lower trophic levels of the food chain/food web being used at that lower level. This energy is stored or used and, therefore, unavailable to the organisms higher up in the chain. As the chain lengthens, less energy is available, usually as a factor of 10 (1/10 of the energy taken in by the level below the consumer is available to the consumer's level, for example).