Long answer short- to reproduce cells.
Answer:
Endosymbiont theory was proposed by Lynn Margulis in 1967 which suggested the origin of Chloroplast and mitochondria in eukaryotic cells.
The theory suggested that chloroplast and mitochondria organelle originated by engulfing the cyanobacteria and proteobacteria by other prokaryotic bacteria.
This shows that Prokaryotes exhibit the following characters:
1. These were the first organisms on Earth
2. Lack membrane-bounded
3. Aerobic bacteria are these types of cells
Eukaryotes exhibit:
1. Have mitochondria
2. Includes organisms that carry out aerobic respiration
3. Can be a multicellular organism
4. Includes organisms that are photosynthetic
5. Might have chloroplasts
Look at these images, the oldest is at the bottom, the newest is at the top, so the drawings are next to time zones are properly set up, so next to the time scale is when the drawing next to it was made.
I believe it would be A one will be eliminated