10.1  Meiosis

big ninja

Essential Idea:

Meiosis leads to independent assortment of chromosomes  

and unique composition of alleles in daughter cells


  • Chromosomes replicate in interphase before meiosis
  • Homologous chromosomes separate in meiosis I
  • Sister chromatids separate in meiosis II
  • Independent assortment of genes is due to the random orientation of pairs of homologous chromosomes in meiosis I
  • Chiasmata formation between non-sister chromatids can result in an exchange of alleles
  • Crossing over is the exchange of DNA material between non-sister homologous chromatids
  • Crossing over produces new combinations of alleles on the chromosomes of the haploid cells


  • Drawing diagrams to show chiasmata formed by crossing over