A third gene pair on a separate autosome determines whether any colour will be produced. The CC and Cc genotypes allow colour according to the expression of the A and B alleles. However, the cc genotype results in albino rats regardless of the Aand Balleles present. Determine the F1 phenotypic ratio of the following crosses:.
A) AAbbCC*AABbcc.
B) AaBBCc* AaBBCc.
C) AABbCc* AABbcc.

During crossing-over, a. genetic material is exchanged between nonsister chromatids, resulting in new combinations of alleles. b. nonsister chromatids from each homologous chromosome of a tetrad are exchanged, resulting in new combinations of alleles. c. one homologous chromosome of a tetrad is exchanged with another tetrad, resulting in new combinations of alleles. d. sister chromatids from each homologous chromosome of a tetrad are exchanged, resulting in new combinations of alleles. e. genetic material is exchanged between sister chromatids, resulting in new combinations of alleles.