Question

which structure will form when a primitive cell engulfs an aerobic bacterium? mitochondria chloroplast nucleus cell membrane

Explanation:

According to the endosymbiotic theory, mitochondria are believed to have originated from an aerobic bacterium engulfed by a primitive cell. Chloroplasts are thought to have originated from a photosynthetic cyanobacterium engulfed by a primitive cell. The nucleus and cell membrane do not have such an origin story related to engulfing an aerobic bacterium.

Answer:

mitochondria