BIOC 212 Lecture Notes - Sic1, Cervical Intraepithelial Neoplasia, Ckts
Figure 17–1 The cell cycle.
The division of a hypothetical eucaryotic
cell with two chromosomes is shown to
illustrate how two genetically identical
daughter cells are produced in each cycle.
Each of the daughter cells will often divide
again by going through additional cell
Figure 17–2 The events of eucaryotic cell division as seen under a microscope.
The easily visible processes of nuclear division (mitosis) and cell division
(cytokinesis), collectively called M phase, typically occupy only a small fraction of
the cell cycle. The other, much longer, part of the cycle is known as interphase.
The five stages of mitosis are shown: an abrupt change in the biochemical state
of the cell occurs at the transition from metaphase to anaphase. A cell can pause
in metaphase before this transition point, but once the point has been passed, the
cell carries on to the end of mitosis and through cytokinesis into interphase. Note
that DNA replication occurs in interphase. The part of interphase where DNA is
replicated is called S phase (not shown).
Figure 17–3 The phases of the cell cycle.
The cell grows continuously in interphase,
which consists of three phases: DNA
replication is confined to S phase; G1 is
the gap between M phase and S phase,
while G2 is the gap between S phase and
M phase. In M phase, the nucleus and then
the cytoplasm divide.