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

Surveys - accidents in industries, Surveys - Accidents in Industries T...

Surveys - Accidents in Industries The surveys done in industries have pointed out that leading cause of accidents is the overexertion or workers working beyond their physical

Explain the double and simple closed circulation, What is the difference am...

What is the difference among double closed circulation and simple closed circulation? Double closed circulation, or closed circulation, is that in which the blood circulates by

Palliative and corrective procedures for cyanotic congenital, Palliative Pr...

Palliative Procedures   i)  This consists of enlarging the existing for a men ovale by putting a baloon through the defect (baloon septostomy) so that interatrial mixing of blo

Amount of intracellular chloride ions in neuron a, Amount of intracellular ...

Amount of intracellular chloride ions in neuron A Neuron A is a healthy neuron with all the usual ion channels.  When at rest with a membrane voltage of R millivolts, neuron A

Percentage of reducing and total sugar by fehling soxhlet, Principle for Es...

Principle for Estimation of Percentage of Reducing and Total Sugar by Fehling Soxhlet Method? Reducing sugars are those which have free sugar groups and hence may be estimated

Explain the alterations occurring in meat and poultry, Alterations occurrin...

Alterations occurring in meat and poultry Meat, as you already know, is  rich in proteins and contains most of the essential amino acids.  It is also rich in minerals such as c

How green leaves make food for plants, Green leaves make food for plants ...

Green leaves make food for plants Heat some alcohol in a jar over boiling water unless it boils. Break various green leaves from a geranium or other plant which has been in the

What is the typical morphological feature of nematodes, What is the typical...

What is the typical morphological feature of nematodes that differentiates them from platyhelminthes? Nematodes are also called as roundworms. As the name shows they are not fl

Define the needs for enteral feeding, Define the needs for Enteral Feeding?...

Define the needs for Enteral Feeding? For enteral feeding following need to be considered: - In preterm calorie density to be 0.8 Kcal/ml, - LBW formulas used: protein -

How is the brain involved in the immune system, How is the brain involved i...

How is the brain involved in the immune system? A. Immune cells that constitute body's biological defense against infections and toxins, have many things in common with nerve c

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