Answer:
The correct answer is- photosynthesis
Explanation:
According to the endosymbiotic theory, an ancestral cell engulfed a cyanobacteria and lived in symbiotic association with that bacteria and over time this bacteria evolved into the chloroplast and the ancestral cell developed into plant cell.
So as cyanobacteria was the first aerobic cell that can evolve oxygen and can do photosynthesis to produce organic food so it could be concluded that the presence of endosymbiotic cyanobacteria provided a cell with the advantage of photosynthesis.
