Question

examine this pedigree showing the inheritance of an autosomal trait. individuals with the recessive phenotype are shaded darker than those with the dominant phenotype. if this trait is represented by the letter r, what is the genotype of individual b? rr rr rr rr or rr

Explanation:

Step1: Analyze offspring of A and B

A and B have an offspring (E) with the recessive phenotype (shaded), so both A and B must carry the recessive allele.

Step2: Determine B's genotype

Since B has a recessive - phenotype offspring, and the trait is autosomal, B cannot be RR. B must have at least one r allele. B has a dominant phenotype, so B's genotype is Rr.

Answer:

Rr