Meiosis160-page6

Meiosis160-page6 - the cell when there is just one of each...

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Meiosis and Life Cycles - 6 The Process of Meiosis Homologous chromosome pairs are essential to how meiosis works. In meiosis the homologous chromosomes literally pair up prior to the reduction of chromosome number. In meiosis, one of each type of chromosome (one of each homologous pair) is distributed to each meiotic product, so that the meiotic products have half as many chromosomes as the "parent" cell. This is the crucial difference between mitosis and meiosis, and explains why we can reduce chromosome number and still have all of the genetic information needed to form a new organism. The homologous pairs of chromosomes in diploid organisms do not interact during mitosis; each chromosome is on its own. After meiosis, the meiotic products have a haploid (half the parental) number of chromosomes, and no pairs of homologous chromosomes. Haploid also refers to
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Unformatted text preview: the cell when there is just one of each kind of chromosome, or the "n" number of chromosomes. (Diploid is the 2n number of chromosomes.) The diploid number of chromosomes will be restored when two gametes (egg and sperm) unite in sexual fertilization. The Process of Meiosis - Details There are three important parts to meiosis: Prior to any cell division, chromosomes must undergo DNA duplication. To achieve the reduction in chromosome number and appropriate distribution of chromosomes, meiosis requires two divisions, called Meiosis I and Meiosis II. Pairing of and separating of the homologous chromosomes occurs in Meiosis I, reducing the chromosome number. Meiosis I Meiosis II Meiosis II separates the duplicated chromosomes. At the completion of the second division, four cells will typically be produced....
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This note was uploaded on 12/29/2011 for the course BIO 151 taught by Professor Edwards during the Spring '10 term at SUNY Stony Brook.

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