Cell Biology
Endosymbiosis
A symbiotic relationship where one organism lives inside the cells of another. The theory that mitochondria and chloroplasts originated as free-living bacteria that were engulfed by ancestral cells.
Biological Context
Endosymbiotic theory explains the origin of eukaryotic cells. Mitochondria retain their own DNA, divide independently, and have bacterial-like ribosomes—evidence of their bacterial ancestry. This ancient partnership enabled the evolution of complex multicellular life by providing efficient energy production.
Business Application
Business endosymbiosis: when one company becomes so deeply integrated into another's operations that they function as one system—critical suppliers, embedded software, essential service providers.