In: Biology
According to the hypothesis of serial endosymbiosis, which of the following was a key initial step in the origin of mitochondria?
A. A eukaryotic host cell engulfed an aerobic, photosynthetic bacterium. |
B. A prokaryotic host cell engulfed an aerobic, heterotrophic bacterium. |
C. A eukaryotic host cell engulfed an aerobic, heterotrophic bacterium. |
D. A prokaryotic host cell engulfed an aerobic, photosynthetic bacterium. |