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Mitosis

Mitosis- Is the division of nuclear material in a continuous process.
It produces new cells ( daughter cells ) that are identical to the parent cell .
It is a form of asexual reproduction.
The process is divided into 5 stages.

Interphase
Prophase
Metaphase }- I P M A T
Anaphase
Telaphase


Stage 1). Interphase


- most of the cells lifetime is spent in this stage.
-it carries out all regular activities EXCEPT reproduction at this stage.

Stage 2 ( early ). Prophase


-chromosomes thicken
-chromosomes assemble material from the cytoplasm to form EXACT duplicates of themselves ( chromatids ).
-these identical chromatids are held together in the centre by a centromere.
-nuclear membrane + nucleolus are intact.

Stage 2 ( late ).


-nuclear membrane + nucleolus start to disappear.
-centrioles move to opposite ends of cell polls.
-fibres begin to form between the centrioles forming a spindle.
-at the same time, chromosomes coil-up like a telephone cord.

Stage 3). Metaphase


-chromosome pairs line up at the equator of the cell + are attached to spindle fibres by the centromere.
-centromere duplicates ( chromosomes are now seperate. )

Stage 4). Anaphase


-spindle fibres contract + pull one set of sister chromosomes to each pole.

Stage 5 ( early ). Telephase


-nuclear membrane + nucleolus reappear around each set of chromosomes.
-spindle disappears.
-chromosomes uncoil to form chromatin.
-centrioles duplicate.
-cell membrane pinches - in.
-cell plate is formed.
-2 identical daughter cells are formed.

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