The Cell cycle reference article from the English Wikipedia on 24-Jul-2004 (provided by Fixed Reference: snapshots of Wikipedia from wikipedia.org)

Cell cycle

The cell cycle is the cycle of events in a cell from one cell division to the next. It consists of interphase, mitosis, and usually cell division.

Phases

Schematic of the cell cycle. I=Interphase, M=Mitosis.
The duration of mitosis in relation to the other phases has
been exaggerated in this diagram.

The phases of the cell cycle are:

• The G₁ phase is the first growth phase.
• The G₀ phase is a period in the cell cycle where cells exist in a quiescent state.
• S phase, during which the DNA is replicated, where S stands for the Synthesis of DNA.
• G₂ phase is the second growth phase, also the preparation phase for the
• M phase or mitosis and cytokinesis, the actual division of the cell into two daughter cells

The cell cycle stops at several checkpoints and can only proceed if certain conditions are met, for example, if the cell has reached a certain diameter. Some cells, such as neurons, never divide once they become locked in a G₀ phase.

Regulation of the cell cycle

The cell cycle is regulated by cyclins and cyclin-dependent kinases.

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