Solution: A man has extra digits (six fingers on each hand and six toes on each foot). His wife and their daughter have a normal number of digits. Having extra digits is a dominant trait. The couple's second child has extra digits. What is the probability that their next (third) child will have extra digits?A. 1/16B. 1/8C. 3/4D. 9/16E. 1/2

Polydactyly is a common inherited malformation leading to having extra digits in hands and feet. Its phenotype is highly variable, in that it may be severe or mild, symmetrical or assymetrical, complete or incomplete. Although this trait has been well understood phenotypically, the nature of the genotypes remains to be cleared for a number of types. In this problem, it would be assumed that only one gene is involved in the condition.