mitosis and meiosis

Mitosis and meiosis - Lecture notes Mitosis cell division in somatic cells original cells produce 2 identical daughter cells growth

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Lecture notes 9/16/09 Mitosis cell division in somatic cells original cells produce 2 identical daughter cells growth repair/replacement of tissue Steps in Mitosis 46 double stranded chromosomes line up at the center of the cell chromosome pairs split and move to opposite ends of the cell cell membrane pinches in and 2 new cells are formed Meiosis gamete production 2 divisions result in 4 haploid gametes Recombination (crossing over) the exchange of genetic material between homologous chromosomes during meiosis Evolutionary significance of meiosis natural selection acts on variation meiosis creates new genetic variation shuffling of chromosomes recombination (crossing over) creates new chromosomes Problems with meiosis Non-disjunction-the failure of homologous chromosomes or chromosome strands to separate during cell division. (trisomy and monosomy) Down syndrome (Trisomy 21) 1/800 to 1/1000 births affects mental development, wide skull, epicantheric fold, heart defects only autosomal trisomy allowing survival to adulthood
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This note was uploaded on 12/05/2011 for the course ANTHRO 102 taught by Professor F during the Spring '11 term at CUNY Queens.

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Mitosis and meiosis - Lecture notes Mitosis cell division in somatic cells original cells produce 2 identical daughter cells growth

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