Meiosis

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Meiosis
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Diploid to Haploid
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Interphase
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Meiosis Iprophase 1
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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

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Meiosis Imetaphase 1 and anaphase 1
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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

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Law of Independent Assortment
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Meiosis Itelophase 1
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Meiosis IIprohase 2
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Meiosis IImetaphase 2 and anaphase 2
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Meiosis IItelophase 2
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Formation of Gametes

• Meiosis only occurs in the reproductive cellsall
  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

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DNA v. Gene
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Karyotype

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