Food chains are simple lists of organisms in an ecosystem, linked by arrows. Many illustrated examples are available from this website.
Grass rabbit fox
In a food chain, what do the arrows represent?
>"is eaten by"
>flow of energy
>flow of organic materials
Food webs include several food chains, fanning outwards and upwards.
Their arrangement shows:
>alternative flows of energy and organic materials
>that organisms can operate at different trophic levels (e.g. sometimes primary, sometimes secondary or tertiary consumers)
>which organisms are competing with others for the same food