What is the defining characteristic of autotrophs?

Autotrophs are organisms that have the remarkable ability to produce their own food through processes such as photosynthesis or chemosynthesis. This characteristic enables them to convert inorganic substances, like carbon dioxide and water, into organic compounds, such as glucose, utilizing energy from sunlight or chemical reactions. This process positions autotrophs at the base of the food chain, as they can thrive independently without relying on other organisms for sustenance.

The other options do not accurately depict the defining nature of autotrophs. For instance, reproduction through cell division is a general biological characteristic that applies to many organisms, including autotrophs and non-autotrophs alike. The inability to produce their own food contradicts the definition of autotrophs—this capability is what distinguishes them from heterotrophs, which depend on consuming other organisms. Lastly, while some organisms feed on others, this behavior pertains specifically to heterotrophs, not autotrophs, which are self-sustaining in their nutritional needs.