The Cell Cycle of Prokaryotes
The cell division of prokaryotes can be broken down into a simple cycle, consisting of three stages. The growth phase, represented as G; the phase when the genome or genetic information is duplicated, S; and the actual division of the cell and fission of the cytoplasm, also called cytokinesis, C.

The above symbolic description of the life of a bacterium is called a cell cycle diagram. This diagram allows a person to refer to different events of the life cycle of the organism. Teachers often refer to the individual stages instead of the cell division as a whole, since it is easier to discuss the process in steps. It is important to remember that cell division is continuous and that the separation of phases is used only to simplify.

The Cell Cycle of Eukaryotes
There are many different types of eukaryotic cells and each type may grow and divide in varying lengths of time. For example, animal and plant cells usually duplicate in 10 to 20 hours but may take longer. Yeast cells divide very quickly, roughly 120 minutes, as do cells of sea urchin embryos. On the other hand, some cells will never divide, such as nerve cells and certain muscle cells.

Eukaryotic cells are much larger than prokaroytic cells and have greater quantities of DNA. Eukaryotic DNA is complex with histones and other proteins, which enables the DNA coil tightly into condensed bundles during cell division. The genomes of nearly all eukaryotic cells are spread into many different chromosomes. Because eukaryotes contain multiple chromosomes, this allows the "reshuffling" of genetic information, called genetic recombination.

The division of eukaryotic cells cant be easily diagrammed into a cell cycle, like the prokaryotic cell division.

The growth, G1, phase of the cell, which in many organisms takes up most of the cell's life. In the synthetic or S phase, DNA is replicated and proteins are synthesized. During this stage every double-helical DNA molecule is duplicated, making two strands of DNA that are exactly identical. Once duplication is complete, histones and other proteins quickly attach to the new DNA molecule. Before and after the S phase are two "gap" stages called G1 and G2. In G1 and G2 phases, DNA is not synthesized, yet damaged DNA can be repaired. Phases G1, S, and G2 are all part of interphase. In interphase the cell continues to grow and produce RNA, proteins and membranes. Throughout the M phase, microtubules assemble themselves, bind to chromosomes and separate sister chromatids. This process called mitosis is necessary for the detachment of two DNA copies. The actual cell division takes place in the cytokinesis, C, phase, creating two daughter cells. Each daughter cell receives about half the contents of the original cell including one copy of the DNA.