Summary A level Biology (OCR A)- Module 2- Mitosis and The Cell Cycle

the cell cycle
the cell cycle is the process that all body cells in multicellular organisms use to grow and divide .




there are 3 Stages of the cell cycle ( mitosis cytokinesis
,
a interphase) and It is controlled by checkpoints
.


.




M phase : Involves both MITOSIS ( nuclear division The cell cycle begins when a cell has been produced by cellular
and cytokinesis ( cytoplasmic DIVISION) division and ends with the cell dividing to produce two Identical
MITOSIS has four stages : cells Interphase
.
full growth Is subdivided into three stages -




-




prophase Az ,
S and G
. .




In gap phase the cell grows and new organelles and
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chromosomes for mutations

S synthesis the cell replicates
.




The cell may undergo apoptosis In ,



4 Its DNA ready to divide by
mitosis .
,




The cell continues growing
and proteins needed for
g
division are made .




CHROMOSOMES .
.
- -
snows now

arranged In
ona

a
is

Eukaryote .




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The x shaped chromosomes
'


i
are made from two strands
' '


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,



joined in the Middle by
'

a i

'

centromere
centromere The separate
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.

.




Strands called chromatids
'
are .
i
.



One
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.


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Sister chromatids refers to chromatid
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Identical chromatids '
.
- - s

T
-




formed during homologous chromosomes sister chromatids

interphase .