noun
- An organism that lives symbiotically inside the cells or body of another organism, especially a microorganism living within a host cell.
Usage: biology; commonly used in discussions of cellular evolution and symbiosis
Examples
- Mitochondria are thought to have originated as endosymbionts billions of years ago.
- The endosymbiont theory explains how eukaryotic cells acquired their organelles.
- Chloroplasts in plant cells are believed to be endosymbionts derived from cyanobacteria.
- Scientists study endosymbionts to understand the evolution of complex life forms.
- The relationship between a host cell and its endosymbiont can become so integrated that they function as a single organism.