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Producers: Organisms found at the start of a food chain. Producers are
autotrophs (an organism which produces its own organic compounds).
Consumers: Organisms which eat others in a food chain. This is all the organisms in a
food chain except the producer(s).
Decomposers: Organisms which feed on dead organisms. They break down
the complex organic chemicals in their bodies, releasing nutrients back
into the ecosystem to be used by other living organisms.
Pyramid of numbers: A chart which shows the relative number of
organisms at different (trophic) levels in a food chain.
Pyramid of biomass: A chart which shows the
relative amount of living mass (biomass) at dif ferent (trophic) levels
in a food chain.