Question

investigating sex - linked inheritance
read the article and use it to answer the question that follows.
sex linked inheritance
why are women often carriers of x - linked traits but rarely affected by them?

Explanation:

Women have two X chromosomes (\(XX\)). For a recessive X - linked trait, they need two copies of the recessive allele (one on each X) to be affected. But they can carry one recessive allele (heterozygous \(X^A X^a\)) without showing the trait. Men have one X (\(XY\)), so if they get the recessive allele on their single X, they are affected.

Answer:

Women have two X chromosomes. To be affected by a recessive X - linked trait, they need two recessive alleles (one on each X). But they can carry one recessive allele (heterozygous) without being affected, as the dominant allele on the other X masks the recessive one's effect. Men have only one X, so a single recessive allele on it causes the trait.