In the Three-Domain Model, the Bacterial Ancestor of Mitochondria Derives

Question

In the three-domain model, the bacterial ancestor of mitochondria derives from ancient
A) fungi.
B) cyanobacteria.
C) respiring bacteria.
D) archaea.
E) protists.

Accepted Answer

According to the three-domain model, the bacterial ancestor of mitochondria derives from respiring bacteria, specifically from the alpha-proteobacteria lineage. This is supported by genetic and biochemical evidence, as well as the endosymbiotic theory, which suggests that mitochondria evolved from a free-living bacterial ancestor that was engulfed by early eukaryotic cells.