Control of the cell cycle, Biology

Assignment Help:

The cell cycle is controlled by a cyclically operating set of reaction sequences that both trigger and coordinate key events in the cell cycle

• The cell-cycle control system is driven by a built-in clock that can be adjusted by external stimuli (chemical message).

• Checkpoint - a critical control point in the cell cycle where stop and go-ahead signals can regulate the cell cycle
o Animal cells have built-in stop signals that halt the cell cycles and checkpoints until overridden by go-ahead signals.
o Three Major checkpoints are found in the G1, G2, and M phases of the cell cycle.

• The G1 checkpoint - the Restriction Point
o The G1 checkpoint ensures that the cell is large enough to divide, and that enough nutrients are available to support the resulting daughter cells.
o If a cell receives a go-ahead signal at the G1 checkpoint, it will usually continue with the cell cycle
o If the cell does not receive the go-ahead signal, it will exit the cell cycle and switch to a non-dividing state called G0
o Actually, most cells in the human body are in the G0 phase.

• The G2 checkpoint ensures that DNA replication in S phase has been completed successfully.
• The metaphase checkpoint ensures that all of the chromosomes are attached to the mitotic spindle by a kinetochore. 


Related Discussions:- Control of the cell cycle

Mrna levels and rna species, You are working at a large, well funded resear...

You are working at a large, well funded research institute with the latest biochemical techniques available. The focus of your research is to find a specific mutation, or set of mu

Ascus, what is ascus ?

what is ascus ?

Evolution conditions, What are the five conditons that can cause evolution ...

What are the five conditons that can cause evolution to take place?

Concept of fitness, While discussing the Darwinian premise of natural selec...

While discussing the Darwinian premise of natural selection we observed that the term selection is synonymous with non-random reproduction, and that the success of the survivors is

Define most probable number (mpn) method, Define Most Probable Number (MPN)...

Define Most Probable Number (MPN) Method? The MPN method is like agar shake tube method where no agar is used. The dilutions of the microbial suspension are made in liquid medi

Types of passive transport, Simple diffusion Only comparatively small u...

Simple diffusion Only comparatively small uncharged or hydrophobic molecules (H2O, O2, and CO2, other gases, urea and ethanol)   cross   the lipid   bilayer   through simple

What is esophagus called, What is the valve that separates the stomach from...

What is the valve that separates the stomach from the esophagus called? What is its function? The valve that separates the stomach from the esophagus is the cardia. It has the

What is electron cloud model, What is Electron Cloud Model ? Electron...

What is Electron Cloud Model ? Electron Cloud Model :  In recent models of the atom, electrons form electron clouds, in which electrons travel in spherical and dumbbell-shap

How do malign neoplasias appear, Q. How do malign neoplasias appear? Th...

Q. How do malign neoplasias appear? The Neoplasias appear due to DNA mutations in genes that regulate the cellular proliferation thus making the cell lose its capacity to contr

Define the factors that affect the rate of drying, Define the Factors that ...

Define the Factors that Affect the Rate of Drying? Factors that affect the rate of drying are as follow: 1) The fat content of the food-Higher fat contents generally result

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd