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

Kreb cycle, where does kreb cycle takes place

where does kreb cycle takes place

Heart failure, It is a clinical syndrome wherein heart fails to pump blood ...

It is a clinical syndrome wherein heart fails to pump blood at a rate required by the tissues of the body or it can do so only with an elevated filling pressure. This may be due to

Give the biological effects of aflatoxin, Q. Give the biological effects of...

Q. Give the biological effects of aflatoxin and List the various natural toxins present in food? Biological effects of aflatoxin include hepatotoxicosis, carcinogenesis and liv

Determine the treatment modalities of cis therapy, The protocol includes fo...

The protocol includes four treatment modalities: A = Mechanical Debridement In this the patients are re-instructed in oral hygiene and motivated to initiate and continue m

Define the causes of failures of root canal treatment, Define the Causes of...

Define the Causes of Failures of Root Canal Treatment 1. Errors in diagnosis and treatment planning 2. Coronal leakage ( inadequate restorative protection) 3. Lack of kno

Ecosystem, what is the main excretory organ of a lizard

what is the main excretory organ of a lizard

How plant transporting substances through tissue, How plants solve the prob...

How plants solve the problem of transporting substances throughout their tissues? In the bryophytes the substance transport is done by the diffusion. In the tracheophytes (pter

What is the plasma membrane of the cell, What is the plasma membrane of the...

What is the plasma membrane of the cell? What are its main functions? The plasma membrane is the outer membrane of the cell; it delimits the cell itself and a cell interior wit

Define lipid-anchored proteins, A large number of integral proteins in euka...

A large number of integral proteins in eukaryotes do not traverse the membrane but are anchored in one or other leaflet of the bilayer through covalent attachment to a hydrocarbon

Define procedure for detection of chalk in flour, Define Procedure for Dete...

Define Procedure for Detection of Chalk in Flour Carry out the experiment following the procedure given herewith: 1. Take a teaspoon of flour in a test tube and shake it wit

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