Characteristics of a Food Chain

In a food chain,

a) there is repeated eating in which each group eats the smaller one and is eaten by the larger one. Thus, it involves a nutritive interaction between the biotic components of an ecosystem.

b) the plants and animals which depend successively on one another form the limbs of a food chain.

c) there is unidirectional flow of energy from sun to producers and then to a series of consumers of various types. Thus, a food chain is always straight and proceeds in a progressing straight line.

d) usually 80 to 90% of potential energy is lost as heat at each transfer on the basis of second law of thermodynamics (transformation of energy involves loss of unavailable energy).

e) usually there are 4 or 5 trophic levels. Shorter food chains provide greater available energy and vice - versa.

f) omnivores occupy more than one trophic level and, some organisms occupy different trophic positions in different food chains.