BIOL 103 Chapter Notes - Chapter 14: Synaptonemal Complex, Meiosis, Zygote
11 Mar 2014
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Meiosis + sexual reproduction haploid: single set of chromosomes sexual reproduction: needs fertilization in which 2 haploid gametes unite to create 1 diploid zygote. ->process of meiosis: haploid ells made by a diploid cell. Crossing over: physical, reciprocal exchange b/w chromosome pieces of homologous (and nonsister) chromatids. # of crossovers controlled by cells; depends on the # and sizes of the chromo. Bivalents organized along metaphase plate: each bivalent aligns on the late idependently of the other bivalents. Bivalents can be randomly aligned on the plate in a variety of ways: 2^n different alignments, with n=23 for humans = 8 million + possibilities on how the bivalents can be separated. B/c homologues are genetically similar but not identical, random alignment of the homologue chromo promotes lots of genetic diversity in haploid cells. Diploid-dominant species: diploid species that have haploid gametes destined for fertilization.
