food chain:The simplest representation of energy in a community. At the base is energy stored in plants, which are eaten by small organisms, which in turn are eaten by progressively larger organisms; the food chain is an oversimplification in that most animals do not eat only one type of organism.
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food web:the interconnected feeding relationships in an ecosystem. These relationships can be complex; some organisms may feed on more than one trophic level, or changes may occur depending on a species' life history stages or the availability of food.