Question

in humans, oculocutaneous (oca) albinism is a collection of autosomal recessive conditions characterized by an absence of the pigment melanin in skin, hair, and eyes. that is, pigmentation (a) is dominant over albinism (a). for this question, assume it is a single gene with two alleles.
if both biological parents display the albino phenotype, what possible phenotypes may be observed in their offspring?
○ marbling of albinism and pigmentation
○ albinism only
○ pigmentation only
○ pigmentation or albinism

Explanation:

Step1: Determine the parents' genotypes

Since albinism is autosomal recessive, and both parents have the albino phenotype, their genotypes must be \(aa\) (homozygous recessive).

Step2: Analyze the possible offspring genotypes

When two \(aa\) parents have children, using the Punnett square (or simple allele combination), the only possible combination of alleles from each parent (\(a\) from each) gives \(aa\) for all offspring.

Step3: Determine the offspring phenotype

With the genotype \(aa\) (homozygous recessive), the phenotype is albinism (as recessive alleles show their phenotype when homozygous).

Answer:

albinism only