CELL DIVISION

-Cells make copies of themselves with identical DNA

Mitosis:
-equal distribution of DNA from one parent to two daughter cells
Stockiness:
-splitting of one parent cell into two daughter cells

-a limited number of cell divisions occur in melodiously organisms for the following reasons:
  -growth of new cells (to keep surface area : volume ratio low)
  -repair of damaged cells
  -replacement of dead cells

-an unlimited number of cell divisions occur in In unicellular organisms for the following reason:
  -reproduction of organisms

chromosome:
-one double helix of DNA on own
-chromosomes must double in size before mitosis occurs

Inter phase:
-stage in cell life when chromosomes copy themselves to double in size
-the two copies are held together by a protein called a syndrome
-each half is now called a chromatid and the pair is called a chromosome

INTER PHASE

-before mitosis occurs, the cells must go through inter phase
Inter phase:
G1 -cell spends 20% of its time in this phase
     -cell grows, carries out life functions and animal cells replicate centralise
S   -cell spends 50% of its time in this phase
     -cell doubles the size of the chromosomes
G2 -cell spends 20% of its time in this phase
     -cell grows, continues to carry out life functions

Mitosis and Stockiness take the remaining 10% of the cell’s time
-one cell makes two cells with identical DNA to the parent cell

Do long sheets on mitosis 

CELL DIVISION (continued)

Cancer:
-uncontrolled mitosis (cells with fixed number of divisions divide out of control)
-treatments for cancer include surgery,  radiation, chemotherapy

Differentiation/Specialization:
-in the first three months after conception (in humans), cells turn on certain genes
-the function is of these cells is determined at this time
-after this point, a cells fate as a certain cell type or tissue is generally fixed