The evolution of eukaryotic cells most likely involved
A) endosymbiosis of an aerobic bacterium in a larger host cell-the endosymbiont evolved into mitochondria.
B) anaerobic archaea taking up residence inside a larger bacterial host cell to escape toxic oxygen-the anaerobic bacterium evolved into chloroplasts.
C) an endosymbiotic fungal cell that evolved into the nucleus.
D) acquisition of an endomembrane system, and subsequent evolution of mitochondria from a portion of the Golgi.

Question

Quizplus · Accepted Answer

The endosymbiosis of an aerobic bacterium (likely an alpha-proteobacterium) within a larger host cell led to the evolution of mitochondria, which are thought to have evolved from the endosymbiont through a process of endosymbiotic gene transfer and reduction of the endosymbiont's genome. This process is supported by a variety of evidence, including the presence of a double membrane surrounding mitochondria, the presence of mitochondrial DNA that is more similar to bacterial DNA than eukaryotic DNA, and the fact that mitochondria are capable of synthesizing some of their own proteins through translation of mitochondrial DNA.

The Evolution of Eukaryotic Cells Most Likely Involved