1 the former is an organism that grows with carbon dioxide as the main carbon source and can survive in an organic-free environment, including plants and bacteria that can carry out photosynthesis and bacteria that can synthesize chemical energy, and is a producer in the ecosystem. The latter can't survive in an organic-free environment, including predatory, parasitic and saprophytic organisms, which are consumers or decomposers in the ecosystem.

The decomposer transforms organic matter into inorganic matter and returns to nature.

Consumers consume organic matter of the previous trophic level.