Chromosomes replicate in interphase before meiosis.
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.
Chiasmata formation between non-sister chromatids can results in an exchange of alleles.
Homologous chromosomes separate in meiosis I.
Independent assortment of genes in due to random orientation of homologous chromosomes pairs in meiosis I.
Sister chromatids separate in meiosis II.
Drawing diagrams to show chiasmata formed by crossing over.
Nature of Science
Making careful observations- careful observations and record keeping turned up anomalous data that Mendel’s law of independent assortment could not account for. Thomas Hunt Morgan developed the notion of linked genes to account for the anomalies.