Mitosis KKesic

How does mitosis produce two genetically identical nuclei?


Mitosis is a type of cell division that in the end produces two daughter cells, with each having the same kind and same number of chromosomes as the parent nucleus.
 Two daughter cells -  occurs when a cell undergoes the cell cycle. The cell cycle has a couple of phases.The first being the interphase; which, as well,  has a couple of stages. The first stage is when the cell grows and matures. The second is when the DNA is copied. The third is when the cell is prepared for division, at this phase the two daughter cells still are not format because their process starts in the mitosis phase but in that phase they are still not developed but the nucleus divides into 2 identical nuclei and from that point in the next phase the two daughter cells are formed.. Mitosis is where the devision of diploid eukaryotic nucleus. The development of the two daughter cells is completed in the cytokinesis phase where the division of the cytoplasm occurs to from two daughter cells.

Figure 1: Cell cycle - from mitosis to two daughter cells which each contain the exact copies of the parent cell's chromosomes.
(Google Images) 

Mitosis is divided intro four stages:

• Prophase - the spindle microtubules grow and extend from each other to the equator from each pole. As they become short an bulky the nuclear envelope breaks down.
• Metaphase - chromatids move to the equator and the spindle microtubules from each pole attach to each centromere on opposite sides.
• Anaphase - the spindle microtubules pull the sister chromatids apart ,which splits the centromeres. This splits the sister chromatids into identical chromosomes. As they are then pulled to opposite poles.
• Telophase - the spindle microtubules break down. The chromosomes unhelix and they are not individually visible. The nuclear membrane reforms. Then, the cell divides to from two daughter cells with identical genetic nuclei. 

During the prophase, the chromosomes become more visible under a light microscope as they superhelix and become shorter and more ponderous. Then, the nuclear envelope fractures. Afterwards, the spindle microtubules grow and extend from each pole to the equator. So, at the metaphase the chromatids move to the equator. The sister chromatids are are two DNA molecules, that are formed by DNA replication; that is also how they are identical. In the anaphase, these sister chromatids are separated. While the spindle microtubules attaches to centromere and pulls the chromatids to opposite poles. The chromosome then occurs - while the sister chromatids are separated they are called chromosomes. Which would mean that each pole has the same chromosomes ( it is the same genetic material). The final step is when the microtubules break down. While the chromosomes unhelix and the nuclear membrane reforms. Then the cell divides into two daughter cells with each having genetically identical nuclei.

Figure 2: How a chromosome looks when duplicated
(Google images)

In further detail, during the DNA replication each chromosome produces an identical of itself; but at this point they are called chromatids and they are attached at the centromere. Then, the chromatids separate at mitosis and from the two identical daughter nuclei.

Figure3: Two daughter cells - showing how they are exactly the same and have the identical nuclei.
(Google images)

Resources:

"IB Biology HL Exam Study." - LiveBinder. N.p., n.d. Web. 11 Nov. 2015.

"The Cell Cycle, Mitosis and Meiosis." — University of Leicester. N.p., n.d. Web. 11 Nov. 2015.

Allott, Andrew, and David Mindorff. IB Biology. Oxford: Oxford UP, 2014. Print. IB Diploma Program - Biology Course Companion.

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