7- Cazz
The Stages of Mitosis
The process of mitosis is divided into 6 stages. The Interphase, Prophase, Metaphase, Anaphase, Telophase, and cytokinasis. At Interphase, there is only one cell, but after cytokinasis there are two identical cells.
Before mitosis can take place, the cell need to store enough energy to drive the chemical processes during the cell division. During this period of time, there is intense cellular activity. The cell grows in size. The length of the grow phase varies between a few hours to a few months. We the cell has stored enough energy, it is ready to divide itself.
The following pictures shows a series of steps of how chromosomes divide. Note that for simplicity, only a few chromosomes are drawn.
Sequence of Stages
1.
Grow phrase
2.
Interphase
3.
Prophase
4.
Metaphase
5.
Anaphase
6.
Telophase
7.
Cytokinasis
What happens at these stages?
1. Interphase
DNA has replicated, but has not formed the condensed structure of chromosome. They remain as loosely coiled chromatin.
The nuclear membrane is still intact to protect the DNA molecules from undergoing mutation.
2. Prophase
The DNA molecules progressively shortenand condense by coiling, to form chromosomes. The nuclear membrane andnucleolus are no longer visible.
The spindle apparatus has migrate to opposite poles of the cell..
3. Metaphase
The spindle fibres attach themselves to thecentromeres of the chromosomes and align the the chromosomes at the equatorial plate.
4. Anaphase
The spindle fibres shorten and the centromere splits, separated sister chromatids are pulled along behind the centromeres.
4. Telophase
The chromosomes reach the poles of their respective spindles. Nuclear envelope reform before the chromosomes uncoil. The spindle fibres disintegrate.
Cytokinasis
This is the last stage of mitosis. It is the process of splitting the daughter cells apart. A furrow