1. Chromosomes replicate in interphase before meiosis.

• Identify tetrad, bivalent, sister chromatids and non-sister chromatids in diagrams of replicated chromosomes.

2. Crossing over is the exchange of DNA material between non-sister homologous chromatids.

• State that crossing over occurs during prophase I.

• Define chiasmata.

3. Crossing over produces new combinations of alleles on the chromosomes of the haploid cells.

• State two consequences of chiasmata formation between non-sister chromatids.

4. Chiasmata formation between non-sister chromatids can result in an exchange of alleles.

• Draw a diagram to illustrate the formation of new allele combinations as a results of crossing over.

• Explain how crossing over between linked genes can lead to genetic recombinants.

5. Homologous chromosomes separate in meiosis I.

• Contrast meiosis I with meiosis II.

6. Sister chromatids separate in meiosis II.

• Describe random orientation and independent assortment.

• Given a parent cell genotype, determine the allele combinations that are possible in the gametes due to independent assortment and random orientation.

7. Independent assortment of genes is due to the random orientation of pairs of homologous chromosomes in meiosis I.

• Compare meiosis II with mitosis.

1. Drawing diagrams to show chiasmata formed by crossing over. [Diagrams of chiasmata should show sister chromatids still closely aligned, except at the point where crossing over occurred and a chiasma was formed.]

• Draw a diagram to illustrate the process and result of crossing over.