Food chain - online puzzles
A food chain is a linear network
of links in a food web starting from producer organisms (such as grass or trees which use radiation from the Sun to make their food ) and ending at apex predator species ( like grizzly bears or killer whales), detritivores ( like earthworms or woodlice), or decomposer species (such as fungi or bacteria). A food chain also shows how the organisms are related with each other by the food they eat. Each level of a food chain represents a different trophic level. A food chain differs from a food web, because the complex network of different animals ' feeding relations are aggregated and the chain only follows a direct, linear pathway of one animal at a time. Natural interconnections between food chains make it a food web.
A common metric used to the quantify food web trophic structure is food chain length. In its simplest form, the length of a chain is the number of links between a trophic consumer and the base of the web and the mean chain length of an entire web is the arithmetic average of the lengths of all chains in a food web.The food chain is a energy source diagram.
Many food webs have a keystone species. A keystone species is a species that has a large impact on the surrounding environment and can directly affect the food chain. If this keystone species dies off it can set the entire food chain off balance.