Compared to the complex steps of mitosis, the process of cell division of bacteria is much simpler. The genetic information in bacteria, also called genome, is only a circle of double-stranded DNA. Sometime early in the bacteria's life, a second copy of its DNA is made. At the replication origin, which is a specific site on the chromosome, over 22 different enzymes work to make an identical copy of DNA. After the enzymes have finished, the cell has two copies of its genome. The two copies are attached side by side to the cell membrane.

Once the bacterial cell has grown to a certain size, cell division of bacteria called binary fission begins. Binary fission is division in which the cell pinches itself in two, creating two equal or nearly equal halves. Between the two attached DNA genomes, a new plasma membrane and cell wall components are built. As new materials continue to be added on, the cell is slowly pinched in two by the plasma membrane, pushing inward. Because the location where the cell constriction starts is between the two DNA copies, each daughter cell is ensured one copy. Eventually the cell is divided and a new cell wall forms around the new membrane, creating two cells from one.