Question

the endosymbiotic theory helps to explain the origin of which structures?
○ mitochondria
○ ribosomes
○ nuclei
○ cell membranes

Explanation:

The endosymbiotic theory proposes that certain organelles in eukaryotic cells originated from free-living prokaryotes that were engulfed by a host cell. Mitochondria are thought to have originated from aerobic prokaryotes that were incorporated into an ancestral eukaryotic cell, matching the core claims of this theory. Ribosomes, nuclei, and cell membranes have different evolutionary origins not explained by endosymbiosis.

Answer:

mitochondria