Difference Between Autotrophs and Heterotrophs


Autotrophs are organisms which are able to make their own organic molecules. Autotrophs are prokaryotes that can produce all of their cellular components from simple molecules such as H2O, CO2, NH3, and H2S. These are self-sufficient cells that utilize CO2 from the atmosphere as the carbon source.


Heterotrophs rely on autotrophs to provide a continuous supply of new organic molecules.  Photosynthesis provides the means by which carbon in carbon dioxide is fixed by conversion to carbohydrates including sugars such as glucose and sucrose, cellulose and starches such as amylopectin.

Carbohydrates are interconvertible and may be converted to fatty acids to make lipids. Other elements may be added to synthesize organic compounds such as proteins.  Carbohydrates, lipids, and proteins can all be used as sources of energy in respiration by both autotrophs and heterotrophs, recycling carbon dioxide so that it may again be used in photosynthesis.

The Autotrophic Organisms Provided the possibility to use oxidative energy in energy supply, and a new heterotrophic category of life forms could develop. The eukaryotes developed from cells by engulfing other bacterial cells which provided the components of the nucleus and mitochondria as well as algae with chloroplasts in the lineage to end up in plants. The animals are heterotrophs.

They benefit from photosynthesis either directly by eating plants as herbivores or indirectly by eating other animals (carnivores) or both animals and plants (omnivores), but also by using oxygen. Pluricellular organisms have specialized cells and tissues with different tasks. The development of present-day plants and animals are outcomes of a 4000 million years of development. Very primitive forms of life still exist, but new simple forms are still developing, as indicated by recent dangerous infections. Thus diversification of life forms continues with the unfortunate extinction of others, often as a result of human activities.

                           Difference between Autotrophs and Heterotrophs

Characteristics Autotroph Heterotroph
Types Chemoautotroph, Photoautotroph Chemoheterotroph, Photoheterotroph
Examples Bacteria and some Plants and Algae Carnivores,  Omnivores and  Herbivores.
How or What they eat Autotrophs produce their own food for energy. Heterotrophs eat other organisms to get energy and proteins.
Presence of Parasites and Saprophytes Parasites and saprophytes are not found autotrophs These plants may be parasites and saprophytes. They draw their nourishment from living hosts or from dead and decaying organisms.

Flow Chart of Autotrophs and Heterotrophs

Autotrophs and Heterotrophs

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Charles Darwin is considered as the 'father of evolutionary biology'.