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Meiosis PowerPoint Presentation

Meiosis

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Meiosis

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  1. Meiosis

  2. Diploid to Haploid

  3. Crossing Over • Synapsis- Homologous Pairs line up = Tetrad • During synapsis the chromstids within a homologous pair may twist around each other and break off and attach to the other homologous pair =Crossing Over • Results in exchange of genetic material between maternal and paternal chromosomes =genetic recombination

  4. Law of Independent Assortment • During metaphase, as the homologous pairs line up the orientation of maternal and paternal chromosomes is random • Not all maternal go to one side, and paternal the other….it is mixed • Law of independent assortment • As the homologous pairs are separated in anaphase, they maternal and paternal chromosomes have random separation • Results in genetic variation

  5. Law of Independent Assortment

  6. Formation of Gametes • Meiosis only occurs in the reproductive cells…all other cells undergo mitosis • Ending products of meiosis are haploid gametes • Eggs in female - oogenesis • Sperm in male - spermatogenesis • Fusion of sperm and egg results in a diploid cell

  7. DNA v. Gene

  8. Karyotype • 46 chromosomes, 23 pair • One of each pair was from mom, one from dad