Cell Cycle

Cell Cycle

Cells reproduce by a cycle of growing and dividing which is referred to as

Interphase

is the longest phase of the cell cycle.

Mitosis

is the division of the somatic cells, which is initiated after the completion of the interphase.

Gap 1 (G1)

is the first stage of interphase that comes before the synthesis of DNA. the longest stage of interphase

Synthesis (S)

is a very crucial part of interphase because this is the time when DNA is synthesized. This stage begins with replication of cellular DNA.

Gap 2 (G2)

comes after DNA synthesis. The cell synthesizes more proteins needed for mitosis.

20 mins

Some embryo cells can complete the cycle in

8 mins

The shortest cell cycle is found in fruit fly embryos which last for only

G1/S checkpoint

checks for the size of the cell, nutrient levels available and needed for cell division, cues from the outside of the cell, as well as the integrity of its DNA.

G2/M checkpoint

the checkpoint prior to mitosis. It checks the integrity of DNA and any replication damage. It is in this stage that DNA damage due to replication is corrected and repaired.

M checkpoint

the checkpoint that happens during mitosis, particularly during the metaphase stage. It ensures that all of the chromosomes are attached to the spindle in preparation for anaphase.

Cancer

a disease characterized by the uncontrolled division of cells. It happens when the regulators of the cell cycle break down.

p53 gene

is to monitor the integrity of the DNA and to check that it is undamaged. If it discovers damage in the DNA, it stops cells division and stimulates the activity of enzymes to repair the damage.

tumor-suppressor gene

By stopping the division of damaged cells, the p53 gene prevents the production of many mutated cells and is, therefore, regarded as a

Metastasis

The process which cancer cells spread from where they originated is called

infect other cells

When cancer cells invade nearby normal tissues or spread through the walls of lymph vessels, they begin to

proliferation of cancer

A diminishing loss of control in the cell cycle leads to the