A food chain is the transfer of food energy from plants to one animal and then to another animal. Most food chains start with green plants that produce food energy from the Sun. Then one animal eats the plant and another animal eats that animal. The green plants in a food chain are called producers.
The term food chain describes the order in which organisms, or living beings, depend on each other for food. Every ecosystem or community of living beings has one or more food chains. The food chain is a linear sequence of organisms in which nutrients and energy are transferred from one organism to another. In a food chain, there is a unique path for energy flow and in a food network, there are different paths for energy flow.
Since autotrophs are the basis of all Earth's ecosystems, most environmental ecosystems follow this type of food chain. In a food chain, an organism eats a single item, while in a food web, an organism consumes several items. However, the food web is able to show the appropriate representation of energy flow, since it shows interactions between different organisms. A food chain refers to the order of events in an ecosystem, where a living organism eats another organism and then that organism is consumed by another larger organism.
The trophic level refers to the sequential stages of a food chain, starting with producers at the bottom, followed by primary, secondary and tertiary consumers. The flow of nutrients and energy from one organism to another at different trophic levels forms a food chain.