Meosis

• Crossing over occurs during.. by..


  1. Occurs during prophase I

  2. Non-sister chromatids wrap around each other very tightly and attach at points called chiasmata
• Recombination is when


  Similar sections of the non-sister chromatids get swapped over, producing new combinations of alleles
• Crossing over leads to variation through recombination
• Reassortment of chromosomes occurs… by…


  1. Occurs during Metaphase I/Anaphase I

  2. Random distribution of homologous pair
• Reassortment of chromosomes leads to


  Each gamete acquires a random mixture of paternal and maternal chromosomes, leading to variation
• Reassortment of chromatids occurs.. by…


  1. Occurs during Metaphase II/Anaphase II

  2. Random distribution of sister chromatids
• Reassortment of chromatids is when


  Each gamete acquires a random mixture of chromatids, leading to variation
• How meiosis leads to genetic variation

  1. Crossing over during prophase 1, shuttle the alleles

  2. Genetic reassortment and random distribution and segregation of the maternal and paternal chromosomes during meiosis I

  3. Genetic reassortment and random distribution of the sister chromatids at meiosis II