Autotrophs are classified by the energy source they use to drive carbon fixation: Autotroph - National Geographic Education
Autotrophic organisms, also known as , are life forms capable of synthesizing their own complex organic compounds (such as carbohydrates and proteins) from simple inorganic substances like carbon dioxide ( CO2cap C cap O sub 2 autotrophic organism
). They serve as the foundational energy source for nearly all ecosystems on Earth, supporting the survival of heterotrophs—organisms that must consume other living things for sustenance. Mechanisms of Autotrophy Autotrophs are classified by the energy source they