Sex-Linked Traits: Why More Common in Males?

The genes responsible for these traits are located on the X chromosome. Males are hemizyguous for the X chromosome meaning they have only one copy of the X chromosome, while females are homozygous having two copies of the X chromosome.

If a male inherits a recessive allele for a sex-linked trait, he will express that trait because there is no dominant allele to mask its effect. In contrast, a female would need to inherit two copies of the recessive allele to express the trait, which is less likely to occur.

Therefore, sex-linked recessive traits are more commonly seen in males than females.