Mitosis and Meiosis Both Mitosis

Mitosis and Meiosis

Both mitosis and meiosis are forms of cellular division in biology and have similar cycles. Mitosis is the process in which a complex cell separates the chromosomes within its cell nucleus into two separate nuclei. Then, this is typically followed by another division called cytokinesis which divides the cell materials into two separate cells. The process is actually quite fast, but incredibly complex and consists of several phases that cause chemical reactions to occur so that cells are divided. Mitosis was discovered in frog, rabbit and cat cells in 1873 (Maton, et.al., 1997, pp. 70-4).

Meiosis is a unique type of cell division that is necessary for sexual reproduction. The cells produced by the process of meiosis are gametes or spores (sperm and egg cells). The process of meiosis is similar to that of mitosis but there are two major differences: 1) in the process of meiosis, the chromosomes undergo a unique recombination that shuffles the genetic code, producing a different combination in each gamete -- instead of the co-existence of each pair of chromosomes that happens in mitosis, and; 2) the outcome of meiosis is four genetically unique haploid cells, compared with two genetically identical diploid cells in mitosis (Maton). Mitosis is used by single-cell organisms to reproduce and in more complex organisms for the growth of tissues. Meiosis is used for sexual reproduction of advanced organisms that allow sperm and egg to fuse to create a new organism.

As noted, the two processes are similar in that they are focused on cellular division. Mitosis is the process of asexual reproduction in which the cell divides into two parts to produce a replication; while meiosis halves the number of chromosomes so they can be merged with another set to produce a full organism. The function of mitosis is cellular reproduction and general growth and occurs in all organisms as asexual reproduction, while meiosis is specific to sexual reproduction and occurs in humans, animals, and plants. The product of the process in mitosis is an identical cell with 1 division and 2 daughter cells; while in meiosis 3 divisions and 4 daughter cells. Within mitosis the chromosomal number remains identical, and the steps are Interphase, Prophase, Metaphase, Anaphase, Telophase and Cytokinesis. In meiosis the chromosomes are reduced in half, with the phases being: Interphase, Prophase I, Metaphase I, Anaphase I, Telophase I, Prophase II, Metaphase II, Anaphase II and Telophase II. Finally, mitosis creates all other cells with the exception of sex cells, while meiosis creates egg and sperm cells only (Meiosis vs. Mitosis, 2008)

Phases -- Meiosis: 1) Meiosis 1 -- separates chromosomes in half; DNA is exchanged and chromosomes coil and uncoil and share information; 2) Metaphase 1 -- Chromosomes align along an equatorial plane; 3) Anaphase 1 -- Kinetochore (bipolar spindles) shorten and pull the chromosomes apart; 4) Telophase 1 -- the chromosomes arrive at the pole and each daughter cell has 1/2 the number of chromosomes; 5) Meiosis II -- final process in which chromosomes are pulled apart and form four haploid cells. Mitosis: 1) Interphase -- preparation for cell division by production of proteins; 2) Preprophase -- in plants only, there is preprophase to mark where cell will divide; 3) Prophase -- chromosomes become tight and condense; 4) Prometaphase -- the hook to catch chromatids that pull genetic material together; 5) Metaphase -- Pulling apart of chromosomes; 6) Anaphase -- elongation of cell in preparation of split; 7) Telophase -- cleans up the cell and elongates it more; 8) Cytokinesis -- completes cell division (Morgan, 2007).