3 Normal Meiosis Starting cell chromosomes Phase showing chromosomes in Meiosis IEnd of Meiosis IPhase showing chromosomesin Meiosis IIEnd of Meiosis IIBoehm
4 Meiosis leads to genetic variability The three sources of genetic variability in a sexually reproducing organism are:Independent assortment of homologous chromosomes and sister chromatids (Punnett square).Crossing over.Random fertilization of an ovum by a sperm.All three mechanisms reshuffle the various genes carried by individual members of a population.BUT mutations are what ultimately create a population’s diversity of genessome mutations can be beneficial, while others can be harmful to an individual.
5 The process of meiosis isn’t perfect Human disorders can result from mistakes in meiosisThese disorders can be caused by:Chromosomal number abnormalities (too many or too few chromosomes)Sections of entire chromosomes can be deleted, added, or swapped.
24 Now can you go diagnose a patient? Well, we wouldn’t really trust you to do that after just this one presentation, but…Use the class handout of three karyotypes to diagnose the patients as “normal” or “abnormal” in terms of chromosome structure and number.