The trophic levels are defined by the groups of the organisms that operate or occupy the same levels of the food chain and each differs in its nutrient relationships with the primary sources of energy.
The most primary source of energy is the sun and provides energy as inputs to the green plants known as autotrophs that make the first order of trophic level.The second level consists of the herbivorous species that are consumers called heterotrophs.
The third level in the trophic is of the carnivorous that survive or depends on other animals and derive their energy from them. Being the top predators of the ecosystem.
Teritary consumers are carnivores at the topmost level in a food chain that feeds on other carnivores; an animal that feeds only on secondary consumers.
