Question

according to the theory of endosymbiosis, a mitochondria or chloroplast may have been a prey species and was engulfed by a cell or it could have been a parasite that entered the cell. why do scientists think that the cell did not destroy or remove these structures? because the structures benefited the cell because they competed with the cell

Explanation:

The endosymbiotic theory states that mitochondria and chloroplasts were once independent prokaryotic organisms that were engulfed by a larger cell. For the cell to retain these structures, there must be a mutual benefit. Mitochondria produce ATP (energy) and chloroplasts perform photosynthesis (in plants), so they benefit the host cell. If they competed, the cell would likely destroy them. So the correct reason is that the structures benefited the cell.

Answer:

A. because the structures benefited the cell