endosymbiotic theory
Mitochondria were bacteria
Endosymbiotic theory explains how complex cells evolved: ancient bacteria were engulfed by host cells and, rather than being digested, became permanent residents.
Mitochondria and chloroplasts—the energy-producing structures in animal and plant cells—retain their own DNA and reproduce independently, evidence they were once free-living organisms.
The theory revolutionized understanding of how eukaryotic life arose.
Light-to-sugar conversion in plants
- cyanobacteriaPhotosynthetic bacteria producing oxygen
- chlorophyllLight-harvesting plant pigment
- stromaSupportive tissue framework
- pigmentsColor-giving compounds
Origin point of descendants
- divergenceSeparation from common origin
- coevolutionReciprocal adaptation between interacting species
Two-way biological benefit
- host cellCell invaded by pathogen
- phagocytosisCellular ingestion of particles
- engulfmentComplete surrounding and absorption
Cell's energy molecule
- aerobic respirationOxygen-using energy production
- cristaeMitochondrial membrane infoldings
- mitochondrial DNAMaternally inherited organelle genome
- cellular energyPower for cell functions
matrix · inner membrane · cytochrome · binary fission · maternal inheritance
photosynthesis
Light-to-sugar conversion in plants
- cyanobacteriaPhotosynthetic bacteria producing oxygen
- chlorophyllLight-harvesting plant pigment
- stromaSupportive tissue framework
common ancestor
Origin point of descendants
- divergenceSeparation from common origin
- coevolutionReciprocal adaptation between interacting species
mutualism
Two-way biological benefit
- host cellCell invaded by pathogen
- phagocytosisCellular ingestion of particles
- engulfmentComplete surrounding and absorption
ATP
Cell's energy molecule
- aerobic respirationOxygen-using energy production
- cristaeMitochondrial membrane infoldings
- mitochondrial DNAMaternally inherited organelle genome
cellular energy · matrix · inner membrane · cytochrome · binary fission · maternal inheritance
paradigm shift
Wholesale replacement of frameworks
binary fission
Asexual splitting into two