Food chain shows how the energy is transferred to the next trophic level.
The linear series of individuals sharing the relationship with each other.
The energy decreases as it is transferred to each trophic level as per 10% law.
The energy from the sun is used by the plants (producers) which are then consumed by herbivores and these are consumed by consumers (primary, secondary and tertiary).
When all these levels are occupied by the same individuals, it is referred to as the food chain.
There are two types of food chain:
Grazing food chain: This starts with producers that are plants; plants are eaten up by herbivores. Herbivores are food for carnivores (secondary consumers) and end up with tertiary carnivores.
Detritus food chain: It begins with the dead and decaying matter of plants and plant parts, consumed by decomposers (detritivores) and then to the organisms feeding on detritivores.
Final Answer:
Food chain is the linear relationship between the organisms that feed on each other at each trophic level.
There are two types of food chain: grazing and detritus.