Cell cycleBiology

What is the cell cycle???

The cell cycle Is the regular pattern of growth , DNA duplication , and cell division that occurs in eukaryotic cells .

Four main stages of cell cycle

Gap 1 (G1)Synthesis (S)Gap2(G2)Mitosis (M)

Gap 1 , Synthesis , Gap 2 together make up is called interphase .

The cell cycle divided into two parts : Interphase :when the cell appeared

to be at rest . Mitosis : when the cell was dividing .

Cell cycle

interphase

Gap 1 synthesis Gap 2

mitosis

mitosiscytokenisi

s

Is the divided of cell cytoplasm

& forming 2 daughter cell

Function of GAP 1(G1) Gap 1 : cell carry out it’s normal

function If it’s a skeletal muscle cell , it

contracts to move joints If it’s an adrenal cell , it secretes

hormones such as adrenaline . If it’s an intestinal cell , it absorbs

nutrients During (g1)cell increase in size and

number of organelles . A cell stays or spend most of its life

in (g1) The cell must pass the check point .

Function of SYNTHESIS (S)

Synthesis means “the combining of parts to make whole”

During the (s) stage , cell makes a copy of its nuclear DNA

At the (S) stage the nucleus of the cell contains ( 2 sets of DNA )

Function of GAP 2 (G2)

Cell continue to carry out their normal functions , and additional growth occurs .

The cell must pass the check point

Function of MITOSIS (m)

The fourth stage of the cell cycle , includes two processes : mitosis and cytokinesis .

Mitosis is the division of the cell nucleus and its contents .

During mitosis , the nuclear membrane dissolves , the duplicated DNA condenses around proteins and separates , and two new nuclei form .

Function of CYTOKINESIS

Is the process that divides the cell cytoplasm .

The result two daughter cell formed

S , G2 , M : they take 12 hr to divide Cell type approximate

life span Skin cell 2 weeks Red blood cell 4 month Liver cell 300-500 days

Done by :

Judy.m. sara .w. Aynoor leen