Cell division is the process by which a single cell becomes two daughter cells. While this process may seem simple, successful cell division must satisfy several important requirements. First, the two daughter cells must each receive the full complement of genetic material (DNA) present in the single parent cell. Second, the parent cell must be large enough to divide in two and still contribute sufficient cytoplasmic components such as proteins, lipids, and other macromolecules to each daughter cell. Satisfying these requirements means that key cellular components must be duplicated before cell division takes place. This duplication of material is achieved in a series of steps that constitutes the life cycle of every cell. When you think of a life cycle, you might think of various stages beginning with birth and ending with death. In the case of a single cell, the life cycle begins and ends with cell division.

In this section, we explore the different mechanisms by which prokaryotic and eukaryotic cells divide. Prokaryotic cells divide by binary fission. When eukaryotic cells divide, they first divide the nucleus by mitosis, and then divide the cytoplasm into two daughter cells by cytokinesis. As we discuss, it is likely that mitosis evolved from binary fission.