Describe Energy pyramid / trophic levels

Energy pyramid is a triangle that represents flow of energy in living organisms.

Explanation:

Specifically, the bottom of triangle occupies producers that includes plants, algae or other autotrophs. Above the producers are primary consumers, then secondary consumers, and then tertiary consumers. In principle, producers fix energy in the form of energy rich compounds (carbohydrates, proteins, and fats) which are then eaten by primary consumers. The primary consumers are eaten by secondary consumers and finally they are eaten by tertiary consumers. Tertiary consumers, after death, release all energy rich molecules in the environment which are then used by microbes or producers to fix energy again.