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Mitosis vs. Meiosis
Mitosis and meiosis are both processes of cell reproduction.
Mitosis is the process by which eukaryotes reproduce asexually and also how multi-celled eukaryotes reproduce cells for bodily growth. Meiosis is the process by which eukaryotes sexually reproduce. Using humans as the examples, new humans are created by meiosis, but within the human, mitosis reproduces cells. Mitosis results in two identical cells, that is the two cells are clones of each other. Meiosis results in four cells that are not identical, the process of meiosis shuffles the genetic information. By describing the two processes, we will see how this occurs.
Mitosis
In mitosis first the chromosome duplicates, creating two sister chromatids, these sister chromatids are identical. The sister chromatids line up in the center of the cells in what is known as a centromere. A spindle then attaches to each chromatid and the cell divides, with one of the sister chromatids in each of the two new cells. At the end of this process, there are two cells identical to the initial cell.
Meiosis
Meiosis begins just as mitosis did with two chromosomes duplicating each other and creating sister chromatids. At the next stage the sister chromatids pair up and condense, with each swapping segments with its partner. It is this vital step that results in a shuffling of genetic information. As in mitosis the sister chromatids are aligned at the center, a spindle attaches to each and the cell splits, with two nonidentical pairs in each new cell. The centrioles now align again in the new cells, spindles attach and the cell splits again. The final result is four cells with non-identical chromosomes in each and each with half the chromosome number. These are the sex or gamete cells, on fertilization two of these gamete cells will fuse giving the full number of chromosomes. This is another way in which genetic information is shuffled.
The diagram below shows the process:
Source: Access Excellence. Mitosis Labeled Diagram. The National Health Museum, 1999.