A man has six fingers on each hand and six toes on each foot

A man has six fingers on each hand and six toes on each foot. His wife has the normal number of digits. Extra digits is a dominant trait. If the man is homozygous for extra digits, then what is the probability that his first child will have extra digits? Select one: 100% 50% 0% 75% 25%

Solution

The chances of inheriting polydactyly by the first child is 100% as the father is homozygous to the trait which means the gametes that are produced will always have the defective gene and since it is autosomal dominant it is expressed even in heterozygous condition.