Question

4. Polydactyl (extra fingers and toes) is due to a dominant gene. A man who is polydactyl, marries a woman with a

normal phenotype. They have a normal child.

a. What is the genotype of the father?

b. What is the genotypes of the mother?

c. Draw a Punnett square and give the genotype & phenotype of the offspring.

Answer 1

a. The genotype of the father is Pp, where P is the dominant allele for polydactyly and p is the recessive allele for normal phenotype.
b. The genotype of the mother is pp.
c. The Punnett square is shown below:

P | p
P | PP | Pp
p | Pp | pp