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

Define the basic types of drying process, Define the Basic Types of Drying ...

Define the Basic Types of Drying Process? Primarily, there are three basic types of drying process: a) Sun drying and solar drying;  b) Atmospheric drying including batch

State the strengths of brief screening measures, Strengths of Brief Screeni...

Strengths of Brief Screening Measures 1) Inexpensive, rapid, portable 2) Needs less training in administration and interpretation 3) Differentiating between dementia and

Define osseointegration and its theories, Define osseointegration and its t...

Define osseointegration and its theories. Osseointegration implies that "it is a contact established without interposition of non bony tissue between normal remodeled bone and

What factor cause the measurement to change, During gym class Sally noticed...

During gym class Sally noticed that her friend Melissa always ran faster than her. Sally knew that they exercised equally, so she wondered what could cause Melissa to run so fast.

Explain dietetics, Explain Dietetics Dietetics  has been defined as  t...

Explain Dietetics Dietetics  has been defined as  the science and art of feeding individuals based  on the principles of  nutrition. It can also be  said  to  be  the "science

What concentration of sucrose solution should administered, The volume of M...

The volume of Mrs. X's plasma was 3 liters before Ed administered the IV. Assume that there was a complete mixing of the administered water with her plasma but no mixing with her i

Determine what is the dose to the thyroid, 1. Compute the mean energy per n...

1. Compute the mean energy per nuclear disintegration, A, for 99m TC if 2.0 x 10 9 Bq of this isotope is injected into a patient. Assume that one-half of the administered dose is

Insulin, INSULIN Linear polymer of b-D-Glucose. Insulin is small-...

INSULIN Linear polymer of b-D-Glucose. Insulin is small-sized (25 - 35 residues) fructosan homopolysaccharide which is a reserve carbohydrate present in roots, tubers and

Mercury, M e rc u r y The metal is biologically non-essential but ...

M e rc u r y The metal is biologically non-essential but being used in various industries, it is released in environment from both natural and anthropogenic sources. Man-m

Define principle for iodine number estimation - lipids, Define Principle fo...

Define Principle for Iodine Number Estimation - Lipids? Iodine number is defined as the number of grams of iodine absorbed by 100 grams of fat, it gives an idea of the relative

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