G Zero and the Cell Cycle
When a cell "decides" that it does not need to undergo
mitosis, but instead, it will just remain an "adult" and accomplish all
of its other functions until it "dies," does it then just lock in to its
G-2 stage, or is the G-1 stage it's final adult resting place.
My recent studies are confusing me about whether the cell is adult and
has its correct number of chromosomes in G-1 or in G-2.
A cell does not enter the Gap 2 (G2) stage unless it is definitely going to
complete mitosis and cytokinesis. The Synthesis (S) phase is a commitment
to cell division. The stage you are referring to is called the G zero
state and the cell does not enter the synthesis stage after completing the
Gap 1 growth phase (G1), but enters the G0 to proceed with its
function. Recently, it has been demonstrated that the G0 may re-enter the
cell cycle and move into mitosis with the proper signals.
As far as I know, G zero is when a cell is in G1. A cell will not begin to
replicate its DNA and go into the S phase unless the proper cell signals are
in place, such as hormones. A cell spends most of its life in G1 until it is
stimulated to divide. Therefore, the chromosomes are in the single-stranded
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Update: June 2012