According to endosymbiosis, what is the best explanation about how eukaryotic cells evolved? Bacteria that were capable of photosynthesis engulfed smaller, heterotrophic bacteria.
Cells that did not fully separate during cellular division fused, forming larger organisms.
Chloroplasts and mitochondria were once prokaryotes that began to live within larger cells.
Two or more prokaryotes fused to form larger, multicellular organisms.