Question

which allele combination represents a female who is heterozygous for a sex - linked trait?
○ x^ry
○ x^ry
○ x^rx^r
○ x^rx^r

Explanation:

• Females have two X chromosomes (\(X^{R}X^{r}\), \(X^{R}X^{R}\)). Males have \(XY\) (\(X^{R}Y\), \(X^{r}Y\)).
• Heterozygous means having two different alleles. \(X^{R}X^{r}\) has two different alleles (\(R\) and \(r\)), while \(X^{R}X^{R}\) has two same alleles.

Answer:

C. \(X^{R}X^{r}\)