From the time of the ancient romans until the late nineteenth century, it was accepted that life arose spontaneously from non-living matter. a seventeenth century recipe for the spontaneous generation of mice required placing sweaty underwear and husks of wheat in an open-mouthed jar and waiting 21 days, during which time it was alleged that the sweat from the underwear would penetrate the husks of wheat, changing them into mice. although such a concept may seem silly today, it is consistent with the other widely held cultural and religious beliefs of that time. francesco redi made the first scientific attack on spontaneous generation in 1668. at that time, it was believed that maggots arose spontaneously in rotting meat. redi believed that maggots developed from eggs laid by flies. to test his hypothesis, redi designed a controlled scientific experiment in which he set out meat in flasks, some open to the air, some covered with gauze, and others sealed completely. as redi predicted, maggots appeared only in the open flasks in which flies could reach the meat and lay eggs. think about redi's experiment described above. it was one step in building cell theory. what aspect of cell theory did redi's experiment support?

a) all cells come from pre-existing cells.
b) cells are the smallest and most basic unit of life.
c) all living things are composed of one or more cells.
d) the cell is the functional unit of all living things.