1 autotrophs are organisms that grow 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 are producers in the ecosystem. Heterotrophs can't live in an environment without organic matter, including predators, parasites and saprophytes. It is a consumer or decomposer in the ecosystem.

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

Consumers consume organic matter of the previous trophic level.