Question

Polydactyly is expressed when an individual has extra fingers/ toes. Having extra digits is caused by a dominant allele. If a man with polydactyly marries a woman with normal number of digits and has one son with normal hands and feet and one with extra digits; what is the probability that their next child will have polydactyly?

A) 1/32
B) 1/8
C) ½
D) ¾
E) 7/16

Answer 1

The probability of their next child having polydactyly is 3 out of 4.

Step-by-step explanation:

To determine the probability of their next child having polydactyly, we need to use the principles of Mendelian genetics. Since polydactyly is caused by a dominant allele, we can represent the man with polydactyly as Pp (where P represents the dominant allele and p represents the normal allele) and the woman with normal digits as pp.

From their previous children, we know that they have one son with normal hands and feet (pp) and one son with extra digits (Pp). When they have another child, there are four possible combinations of alleles for that child: PP, Pp, pP, and pp. The probability of the child having polydactyly (Pp or PP) is 3 out of 4.