A food chain is a linear sequence of organisms through which nutrients and energy pass when one organism eats another. In a food chain, each organism occupies a different trophic level, defined by the amount of energy transfers that separate it from the basic input of the chain. A food chain explains which organism eats another organism in the environment. The food chain is a linear sequence of organisms in which nutrients and energy are transferred from one organism to another.
This occurs when one organism consumes another organism. It starts with the producing organism, follows the chain and ends with the decomposing organism. After understanding the food chain, we realize how an organism depends on another organism to survive. Since autotrophs are the basis of all Earth's ecosystems, most environmental ecosystems follow this type of food chain.
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. About 50% of the energy (possibly up to 90%) in food is lost at each trophic level when an organism is ingested, making it less efficient to be a higher-order consumer than a primary consumer. Because of this inefficiency, there is only enough food for a few high-level consumers, but there are plenty of foods for herbivores that are further down the food chain. In a food chain, there is a unique path for energy flow and in a food network, there are different paths for energy flow.
Therefore, the transfer of energy from one trophic level to the next, up the food chain, is like a pyramid; wider at the base and narrower at the top. Just as an arc collapses when the cornerstone is removed, an entire food chain can collapse if a key species declines. 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. As you probably know, the organisms at the base of the food chain are photosynthetic: terrestrial plants and the phytoplankton (algae) of the oceans.
In a food chain, an organism eats a single item, while in a food web, an organism consumes several items. The flow of nutrients and energy from one organism to another at different trophic levels forms a food chain.