The Ten percent law for the transfer of energy

Energy

In physics, energy is an indirectly observed quantity. It is often understood as the ability a physical system has to do work on other physical systems...

 from one trophic level

Trophic level

The trophic level of an organism is the position it occupies in a food chain. The word trophic derives from the Greek τροφή referring to food or feeding. A food chain represents a succession of organisms that eat another organism and are, in turn, eaten themselves. The number of steps an organism...

to the next was introduced by Lindemann (1942).
According to this law, during the transfer of energy from organic food from one trophic level to the next, only about ten percent of the of energy from organic matter is stored as flesh. The remaining is lost during transfer or broken down in respiration.

The food chain

Plants absorbs 1% sun energy for primary production and can store only 10% of the utilized energy as net production available for the herbivores. When the plants are consumed by animal, about 10% of the energy in the food is fixed into animal flesh which is available for next trophic level (carnivores). When a carnivore consumes that animal, only about 10% of energy is fixed in its flesh for the higher level.