Endosymbiosis
Endosymbiosis
The endosymbiotic theory proposes the engulfing, but not digesting, of prokaryotic cells by eukaryotic cells resulted in a mutually benefitting relationship, or symbiosis. This theory explains the presence of mitochondria in eukaryotic cells as well as a an individual mitochondrial genome, separate from the main genome of a eukaryotic cell.[1]