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 albino characteristics (a). for this question, assume the phenotype is determined by a single gene with two alleles. if both biological parents display the albino phenotype, what are all of the possible genotypes that may be observed in their offspring? \\( \bigcirc \\) aa and aa \\( \bigcirc \\) aa only \\( \bigcirc \\) aa, aa, and aa \\( \bigcirc \\) aa only

Explanation:

Step1: Determine the parents' genotypes

Since albinism is autosomal recessive, individuals with the albino phenotype must have the \(aa\) genotype.

Step2: Analyze the offspring's genotypes

When both parents have the \(aa\) genotype, the only possible combination of alleles they can pass on to their offspring is \(a\) from each parent. Using a Punnett square:

	\(a\)	\(a\)
\(a\)	\(aa\)	\(aa\)

So, all offspring will have the \(aa\) genotype.

Answer:

D. \(aa\) only