Question

a father is homozygous for the trait of polydactyly (pp) - he has extra fingers &/or toes. the mother does not have polydactyly (pp). what is the probability that their child will have extra fingers &/or toes?
○ 75%
○ 0%
○ 25%
○ 100%

Explanation:

Step1: Determine Parental Genotypes

Father: \( PP \) (homozygous dominant), so he can only pass on \( P \) alleles.
Mother: \( pp \) (homozygous recessive), so she can only pass on \( p \) alleles.

Step2: Use Punnett Square

The Punnett square for this cross will have all offspring with genotype \( Pp \). Since \( P \) (polydactyly) is dominant, any offspring with at least one \( P \) allele will express the trait.

Step3: Calculate Probability

All offspring (\( Pp \)) will have the dominant allele \( P \), so the probability of having polydactyly (extra fingers/toes) is \( 100\% \).

Answer:

100%