Obtain two apples of the same variety, size, and condition.

Cut a small slit into each of them with a knife.

Place an adhesive bandage on one, leaving the other exposed to the air. After three days you will find that the bandage slows down bacterial growth.

This activity can be repeated by putting some iodine or other disinfectant on the cut of one apple instead of the bandage.

Is "adhesive bandage" like a band-aid? It might be different if a strip of adhesive tape (without the gauze pad) were placed on the cut. You might try sealing the cut with
plastic wrap.