Sunday, September 6, 2009

Mitosis (Cell Division)


This was the most boring biology lesson for me back when I was second year high school because.. yeah.. it wasn't explained clearly and well. It became an easy topic because my teacher sir Greg gives a simple explanation about it. It is really good to use power point presentations for this kind of lessons because you can present images as well as illustrations at the same time and explain it. 

 Let me start this by defining Mitosis, Mitosis is a process of cell division which results in the production of two daughter cells from a single parent cell. The daughter cells are identical to one another and to the original parent cell.

There are 5 stages of mitosis: interphase, prophase metaphase, anaphase and telophase.  

First, the interphase, in this period the nuclear membrane is still intact to protect the DNA molecules and the chromosomes are still coiled. Prophase then comes next, this phase includes the chromatin in the nucleus begins to condense, the nucleolus disappears, and centrioles begin moving to opposite ends of the cell. In the metaphase stage, the miotic spindle apparatus has now formed and lies on the opposite poles of the nucleus, the chromosomes are lined up in the cells equatorial plate and are also attached to the spindle fibres. After the metaphase is the anaphase, in which the paired chromosomes are being pulled and moved along the opposite poles of the cells. Lastly, telophase, wherein the chromosomes have finished their migration to the poles and forms two daughter cells, chromosomes become as they are in the interphase and the nuclear membrane forms again.

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