Final answer:
According to the cell theory, maggots cannot form spontaneously from rotting garbage. They are the larvae of flies and only appear when flies lay their eggs on decaying organic matter.
Step-by-step explanation:
According to the cell theory, which states that cells are the basic units of life and that all living organisms are composed of cells, maggots cannot form spontaneously from rotting garbage. Maggots are the larvae of flies, and they only appear when flies lay their eggs on decaying organic matter. This was demonstrated by Francesco Redi in an experiment that showed maggots developing on meat that had been exposed to flies, but not on meat that was protected from flies by a covering. Therefore, your friend is not correct in saying that rotting garbage can turn into maggots without the presence of flies.