Chapter 7.B, Problem 60E

Dominant and Recessive Genes. Many traits are controlled by a dominant gene, A, and a recessive gene, a. A child gets two genes, one from each parent. Suppose a child's parents each have the gene combination Aa; that is, each parent is equally likely to pass either the A or the a gene to the child. Make a table showing the probability distribution for the child; possible gene combinations, which are AA, Aa, and aa- If the combinations AA and Aa both result in the same dominant trait (say, brown hair) and aa results in the recessive trait (say, blond hair), what is the probability that a child will have the dominant trait? What is the probability that the child will have the recessive trait?