A heterotroph is an organism that requires organic substrates to get its carbon for growth and development. Contrast with autotrophs which use carbon dioxide as sole carbon source. All animals are heterotrophic, as well as fungi and many bacteria. Some parasitic plants have also turned fully or partially heterotrophic, whereas carnivorous plants use their flesh diet to augment their nitrogen supply, but are still autotrophic.
See also : Primary nutritional groups