RLO: Cell Division

The Cell cycle

The cell cycle is a series of changes that the cell goes through from the time of formation until it is reproduced through cell division. Most cells spend only a small amount of their time engaged in cell division. This period of time, the majority of the cell’s functional life, is know as interphase.

During interphase the cell performs all the metabolic functions necessary for it to survive. Cells at this stage in the cycle are in the G₀ phase of interphase. Some mature cells, such as nerve cells remain at this stage and do not divide. However, most cells will eventually divide by mitosis. An interphase cell preparing to divide will progress through three phases of interphase before mitosis.

The G₁ phase is described as the growth phase when the cell manufactures enough organelles for cell division. The S phase involves DNA replication. The aim of this replication is to make a copy of the genetic material in the nucleus to ensure that the two ‘daughter’ cells that are formed receive identical copies of the genetic material. Prior to mitosis the cell then enters the G₂ phase during which more protein synthesis take place.