Definition of endogenous
- endogenous plant roots
- suffered from endogenous depression
- endogenous business cycles
- an endogenous hormone
These example sentences are selected automatically from various online news sources to reflect current usage of the word 'endogenous.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.
When biologists need to make a distinction between things that are produced within a cell or organ and things that affect it from the outside, they use the terms endogenous and exogenous. It used to be thought, for instance, that mutations in cells always resulted from exogenous causes, until it was discovered that substances in the body, including those called oxidants, could cause them endogenously as well. "Circadian rhythms"—the regular cycles, roughly 24 hours in length, that plants, animals, and humans rely on to regulate their days—are endogenously generated and don't actually depend on the sun for their timing.
What made you want to look up endogenous? Please tell us where you read or heard it (including the quote, if possible).
Confusing Words—A Quiz