Department of Energy Argonne National Laboratory Office of Science NEWTON's Homepage NEWTON's Homepage
NEWTON, Ask A Scientist!
NEWTON Home Page NEWTON Teachers Visit Our Archives Ask A Question How To Ask A Question Question of the Week Our Expert Scientists Volunteer at NEWTON! Frequently Asked Questions Referencing NEWTON About NEWTON About Ask A Scientist Education At Argonne G Zero and the Cell Cycle
Name: Frank
Location: N/A
Country: N/A
Date: N/A


Question:
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.



Replies:
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.

Steve Sample


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 form.

Van Hoeck



Click here to return to the Biology Archives

NEWTON is an electronic community for Science, Math, and Computer Science K-12 Educators, sponsored and operated by Argonne National Laboratory's Educational Programs, Andrew Skipor, Ph.D., Head of Educational Programs.

For assistance with NEWTON contact a System Operator (help@newton.dep.anl.gov), or at Argonne's Educational Programs

NEWTON AND ASK A SCIENTIST
Educational Programs
Building 360
9700 S. Cass Ave.
Argonne, Illinois
60439-4845, USA
Update: June 2012
Weclome To Newton

Argonne National Laboratory