EVERYDAY SCIENCE

Detailed explanation-1: -Key Points. 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.

Detailed explanation-2: -Generally, there are no more than four trophic levels because energy and biomass decrease from lower to higher levels.

Detailed explanation-3: -Generally, there are a maximum of four trophic levels. Many consumers feed at more than one trophic level. Humans, for example, are primary consumers when they eat plants such as vegetables. They are secondary consumers when they eat cows.

Detailed explanation-4: -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.