Question

Human skin color is controlled by multiple genes, and the inheritance of thistrait is considered quantitative-the more the number of dominant alleles,the darker the skin color. What are the chances that an AaBbCC man and anaabbCc woman can have an AaBbCc offspring?

Answer 1

The number of gametes that the father provides is 2^n, which is the number of heterozygotes. So he will provide 4 gametes: ABC, AbC, aBC and abC. The mother also provides 4 gametes: Abc, AbC, abC and abc. So crossing all of them, the probability of that couple having an AbBbCc offpring is 1/8.