The core theoretical framework is the endosymbiotic theory, which posits that eukaryotic cells evolved through cooperative relationships between distinct prokaryotic lineages. This mechanism explains the origin of membrane-bound organelles, specifically the nucleus derived from membrane folding and mitochondria/chloroplasts derived from engulfed bacteria, establishing the structural and functional basis for complex multicellular life. The domain is cellular biology within the broader discipline of evolutionary biology, where the theory serves as a fundamental explanation for the transition from simple prokaryotic to complex eukaryotic cellular organization.
Prerequisite chain context: requires Prokaryotic vs Eukaryotic Cell Structures.