Question

If the phenotype followed in Pedigree 3 is autosomal recessive, then what is the genotype of I-1? Assume no new mutations and complete penetrance.

a. Homozygous dominant
b. Heterozygous
c. Homozygous recessive
d. Hemizygous dominant
e. Hemizygous recessive

Answer 1

If the phenotype followed in Pedigree 3 is autosomal recessive, then the genotype of I-1 would be homozygous recessive (aa).

Step-by-step explanation:

In Pedigree 3, if the phenotype follows an autosomal recessive inheritance pattern, then individual I-1 must be homozygous recessive for the trait. This means that the genotype of I-1 is aa. In autosomal recessive inheritance, affected individuals have two copies of the recessive allele (aa), while carriers have one copy (Aa). Therefore, since I-1 is affected by the trait, they must have inherited the recessive allele from both parents.