Endosymbiotic Theory

Definition

The endosymbiotic theory is the scientific explanation of how eukaryotic cells, which make up complex organisms like plants and animals, evolved. It proposes that certain organelles within eukaryotic cells, such as mitochondria and chloroplasts, were once free-living prokaryotic organisms that formed a symbiotic relationship with larger host cells.

Related terms

Mitochondria:

These are small organelles found in most eukaryotic cells that act as the powerhouses by producing energy in the form of ATP.

Chloroplasts:

Chloroplasts are organelles found in plant cells responsible for photosynthesis, converting sunlight into chemical energy.

Prokaryotes:

Prokaryotes are single-celled organisms that lack a nucleus and membrane-bound organelles. Bacteria and archaea are examples of prokaryotes.