The Cell Cycle
(Timing of somatic cell division)
This follows the introduction
to cell division, and accompanies
the page about mitosis.
The whole cycle of somatic cell division typically lasts from
8 to 24 hours in humans. This is represented in the pie-chart below.
As shown in the pie-chart, the part of the cell cycle during which
the nucleus of the cell is dividing (which is called
mitosis) occupies approx. 10% of the time taken for
the whole cycle. The Cytokinesis phase takes approx.
half of this time.
Most of the cell cycle
is the period in which the cell is not dividing
A pie-chart is a simple way to represent this timing information:
Above: Typical timing of somatic cell division.
Summary of the Stages of the "Cell Cycle" for
From the page about mitosis: In
all somatic cells (that is, all cells relating to the non-reproductive
parts of the body = all cells except for those of the gametes)
the "cell cycle" consists of two periods:
- Interphase (also
known as "interkinesis")
is the period in which the cell is not dividing.
This does not mean that little is happening as interphases
are very active periods during which cells perform
all the functions necessary for life, and also synthesise
DNA (deoxyribonucleic acid) so that both
of the new cells formed by the miotic phase will contain
a complete copy of the original, and so have everything
- Miotic phase (M)
- when the cell is dividing.
The miotic phase of the "cell cycle" consists of two stages:
Mitosis is the division of the cell nucleus, and is followed by:
Cytokinesis is the division of the cytoplasm of the cell into two daughter
For further detail about mitosis see the diagram