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:

Since the trait is autosomal and shaded individuals (like E and I) have the recessive phenotype (rr). For parents A and B to produce a child (E) with the recessive phenotype (rr), each parent must contribute one recessive allele (r). Parent A and B are not shaded, so they have at least one dominant allele (R). So, parent B must have the genotype Rr (one dominant allele to show the non - shaded phenotype and one recessive allele to pass to child E).

Answer:

C. Rr