The series of organisms of an ecosystem through which the food and energy present in it and passes with each member is called food chain. A food chain consists of producers (green plants), consumers (animals and man) and decomposers (micro organisms). Basically there are two types of food chains: grazing food chain and detritus food chain.
In an ecosystem single food chains never occur. The same organisms may operate at more than one tropic level. So different food chains are inter connected. Thus, in an ecosystem several food chains are linked together and intersect each other to form a complex network called food web.
Definition: A number of food chains form a interlinking pattern forming a web like arrangement known as food web.
Food Chain vs Food Web
2. Usually members of higher trophic level* feed upon a single type of organisms of lower trophic level
3. Isolated or separate food chains increases the instability of the ecosystem
4. It does not have any effect on improving the adaptability and competitiveness of the organisms
1. It consists of number of interconnected food chains through which food energy travels in an ecosystem
2. Usually members of higher trophic level feed upon many organisms of lower trophic level
3. Presence of complex food webs increases the stability of the ecosystem
4. More complex food webs improves the adaptability and competitiveness of the organisms
* Trophic level: The various steps or levels in an ecosystem are called trophic levels.