Question

What is a sex linked trait? What is the difference in inheritance between boys and girls for sex linked traits? Describe an example of a sex linked trait in humans.

Answer 1

A sex-linked trait is a trait that is carried by the X chromosomes in females but it is not expressed(the phenotype). Females are only carriers because they have two copies of the X chromosome [one of them carries the trait and the other does not]. Males who inherit one copy of the X chromosome often get the trait (because the trait is in either one copy or the other of the X chromosome) and express it while their Y chromosome would became recessive. Thus, only males express sex-linked traits such as hemophilia or color blindness