Define trophic level.

The trophic level is the position an organism occupies in the food chain. The first trophic level known as the base of the ecosystem has the highest energy concentration which is transferred to the organisms at different trophic levels. Following are the different levels of an ecosystem:

• Producers: Plants and other autotrophs are known as producers. They prepare their own food using sunlight and carbon dioxide by the process of photosynthesis. This energy is transferred to the organisms that feed on the producers.

• Primary Consumers: This is the second trophic level which includes all the herbivores. Animals such as cows, buffaloes, deer, few insects cannot prepare their food and rely on plants and natural products for nutrition. 

• Secondary Consumers: A few organisms such as rats, foxes, fish belong to the third trophic level. These are secondary consumers and derive their nutrition from the primary consumers. 

• Tertiary Consumers: This is the fourth trophic level that includes all the carnivores and omnivores. 

• Apex Predators: This is the final trophic level of the ecosystem. The animals belonging to this trophic level have no predators of their own. Eagles, lions, anacondas, belong to this trophic level.