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
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
Web references
Cool Antarctica has some great images and information about visits to an area which most of us can only dream about. It also has a quite impressive Antarctica Schools Resources
section.
This topic has connections with other units on this site:-
Ecosystems