Recombination between unlinked markers

Where the loci A and B are unlinked on separate chromosome pairs, the cross between parental AABB x aabb produces the double heterozygote F1 AaBb. When backcrossed to an aabb tester, the F1 produces AB, Ab, aB, and ab gametes in equal ratios, and the recombinant Ab and aB gametes are 50% of the total

Figure ©2002 by Griffiths et al.; all text material ©2015 by Steven M. Carr