Biology, asked by omrajendrasinghpawar, 1 year ago

With the help of suitable diagrams explain the mitosis in detail

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Answered by rohan3106
26
Mitosis (Nuclear Division)

0. Interphase

Interphase is not part of mitosis but is included here as a reminder that interphase preceeds mitosis. (Hence, it has the number 0.)


Chromatin is material in a cell nucleus consisting of DNA and protein. This is the substance that chromosomes are made from. It can be stained with dyes in order to watch the process of mitosis using a microscope.


1. Prophase

Early in the prophase stage the chromatin fibres shorten into chromosomes that are visible under a light microscope. (Each prophase chromosome consists of a pair of identical double-stranded chromatids.)

Above: Early Prophase

Later in prophase, the nucleolus disappears, the nuclear envelope breaks down, and the two centrosomes begin to form the miotic spindle (which is an assembly of microtubules).
As the microtubules extend in length between the centrosomes, the centrosomes are pushed to opposite "poles" (extremes) of the cell.
Eventually, the spindle extends between two opposite poles of the cell.

Above: Late Prophase


2. Metaphase

Metaphase is characterized by the "metaphase plate". This is a mid-point region within the cell that is formed/defined by the centromeres of the chromatid pairs aligning along the microtubules at the centre of the miotic spindle.




3. Anaphase

The centromeres split seperating the two members of each chromatid pair - which then move to the opposite poles of the cell: When they are seperated the chromatids are called chromosomes.

Above: Early Anaphase

As the chromosomes are pulled by the the microtubules during anaphase, they appear to be "V"-shaped because the centromeres lead the way, dragging the trailing arms of the chromosomes towards the pole/s.

Above: Late Anaphase

4. Telophase

Telophase begins after the chromosomal movement stops.
The identical sets of chromosomes - which are by this stage at opposite poles of the cell, uncoil and revert to the long, thin, thread-like chromatin form.

A new nuclear envelope forms around each chromatin mass.
Nucleoli appear.
Eventually the miotic spindle breaks-up.

0. Interphase - see top of page

The cycle is about to start again ...


Two new "daughter cells" - the cycle is about to repeat itself.
Interphase is not part of mitosis but is included here as a reminder that interphase preceeds mitosis. (Hence, it has the number 0.)
Answered by pallavi2567
11

I Hope this is helpful for you

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