Why is it easier to identify a recessive sex-linked trait in human beings than a recessive autosomal trait?
A) A male needs only to inherit one recessive allele to express an X-linked trait
B) A male needs to inherit two recessive alleles to express an X-linked trait
C) A female only needs to inherit one recessive allele to express an X-linked trait
D) All of these
E) None of these

Question

Quizplus · Accepted Answer

In human beings, males only have one X chromosome and one Y chromosome, while females have two X chromosomes. Since the gene for a recessive sex-linked trait is present on the X chromosome, if a male inherits a single recessive allele on his X chromosome, he will express the trait. On the other hand, autosomal recessive traits require the individual to inherit two recessive alleles, one from each parent, to express the trait. Therefore, identifying a recessive sex-linked trait is easier because it only requires one recessive allele in males.

Why Is It Easier to Identify a Recessive Sex-Linked Trait