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

What is the meaning of food exchanges, What is the meaning of Food Exchange...

What is the meaning of Food Exchanges Food exchanges mean grouping of foods in which the specified amount of all the food provides approximately equal amounts of carbohydrate,

What are the two main types of endocytosis, What are the two main types of ...

What are the two main types of endocytosis? Endocytosis can be divided as pinocytosis or phagocytosis. In pinocytosis small particles on the external surface of the membrane ex

What are some of the possible treatments, My friend was injured several yea...

My friend was injured several years ago in a car accident and she was diagnosed with a herniated disc. Can you please explain using the correct anatomical terminology what herniati

Vitellogenesis, Vitellogenesis Vitellogenesis is the stage where much ...

Vitellogenesis Vitellogenesis is the stage where much of the oocyte growth occurs. The completion of second maturation division (meiosis), which may occur after ovulation, res

Implantable cardioverter defibrillator, Patients with aborted sudden death,...

Patients with aborted sudden death, hemodynamically unstable ventricular arrhythmias, and unexplained cardiogenic syncope are at high risk for fatal ventricular arrhythmias. If the

Population growth curve, Increase in population size is known as population...

Increase in population size is known as population growth. It depends upon number of persons added to the population and number of persons lost from the population. Addition in pop

Climax forest - xerarch, Climax Forest - Xerarch First, some xerophyti...

Climax Forest - Xerarch First, some xerophytic species of trees, establish in this area. They are sparsely distributed and are stunted because the conditions are still not ver

Explain clostriduim botulinum, Q. Explain Clostriduim botulinum? Clostr...

Q. Explain Clostriduim botulinum? Clostriduim botulinum is widely distributed in soil and marine sediments throughout the. world. It is also found in the intestinal tract of a

Insects - hormones in growth and reproduction, Insects - Hormones in Growth...

Insects - Hormones in Growth and Reproduction In insects hormones regulate moulting and metamorphosis. The larvae or nymphs which hatch out of the eggs undergo regular moultin

Categories of air pollutants, Categories of Air Pollutants From the ab...

Categories of Air Pollutants From the above list you can see that the air pollutants can be broadly classified into the following two categories: Primary Pollutants

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