Independent Assortment The orientations of the homologous chromosomes at the equatorial plate of the spindle is random. That is, each time they line up at the equatorial plate, the two pairs of chromosomes in a homologue may appear on different sides of the plate. As you have already learned in the previous page, the alleles on the two homologous chromosomes are different. Thus, when the cell separates during meiosis, the resulting cells contain different genetic codes. The following example illustrates independent assortment.   When the cells separate, they would give rise to different daughter cells.

What are the possibilities? The number of different gamete types resulting from independent assortment of the homologues can be calculated using the formula 2n where n=  (total number of chromosomes / 2). Example 1 A fruit fly has 8 chromosomes, how many different gametes can be produced due to independent assortment? 　 Example 2 A man has 46 chromosomes, how many different gametes can be produced due to independent assortment? Probability= 24 = 16 Therefore 16 different gametes can be produced. Probability= 223 = 8.5 million Therefore 8.5 million different gametes can be produced.

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