Cell Biology:
MITOSIS:
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Occurs in all body cells
In such cells there are 2 sets of each chromosome – one maternal and one paternal – 2n
In total there are 46 chromosomes and there can only ever be 46 chromosomes*
In a cell that has replicated there will be 92 chromatids – still only 46 chromosomes
STAGES OF MITOSIS:
Interphase:
Majority of the time a cell cycle the cell is in interphase.
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DNA replication
Protein synthesis
Carrying out cellular functions
Prophase:
This is the beginning of mitosis.
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The nuclear membrane begins to disappear
The chromatins (genetic material) begin to condense
The centrioles move to the poles
The nucleolus disappears
Metaphase:
This is when the nucleus is beginning to divide
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The chromosomes line up in the centre of the cell along the equator
The spindle fibres attach to the centromere
The centrioles are at the poles of the cell
Anaphase:
This is the direct spilt of the chromatids
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The spindle fibres contract
The sister chromatids full away from each other
There are now 92 chromosomes – 46 at each pole
Telophase:
The final part of mitosis
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The nuclear membrane reforms around the now separate chromatids
The chromosomes diffuse and become less compact