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

Question

Quizplus · Accepted Answer

The endosymbiotic theory proposes that mitochondria originated from the engulfment of proteobacteria by an ancestral host cell. This theory is supported by several lines of evidence, including the similarity between mitochondrial and proteobacterial DNA, the presence of a double membrane in mitochondria, and the fact that a variety of proteobacteria can live intracellularly in eukaryotic hosts. None of the other choices in the question are supported by the evidence.

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