Genetic variation in meiosis

• How does it meiosis increase genetic variation:

  • Mum and dad chromosome 1 and 1
  • Copied in interphase x and x
  • Sister chromatids joined at centromere x
  • Chromatids of chromosomes wrap around each other
  • This is crossing over
  • The point where x and x, non-sister chromatids join is chiasma
  • Parts of chromatids break off
  • Alleles are exchanged
• Independent assortment of chromosomes:

  • Which chromosome from each pair moves to which pole
  • Random

  AND crossing over:

  • exchange of alleles between non-sister chromatids
  • of homologous pair
  • which are joined at the chiasma
  • result in a different combination of alleles