Question

If a boy exhibits a sex-linked trait that is carried on the X chromosome, what must be true?

Answer 1

Answer:

Your answer is D!

Explanation:

His mother carried at least one allele for that trait.

Answer 2

Answer:

C. His mother carried at least one allele for that trait

Explanation:

-Men have a single allele of each gene on the X chromosome, inherited from their mother, and a single allele of each gene on the Y chromosome, from their father.

-A sex-linked trait is a trait that is controlled by a gene or an allele located on the sex chromosome.

-X-linked traits are maternally inherited from carrier mothers or from an affected father. Each son born to a carrier mother has a 50% probability of inheriting the X-chromosome carrying the mutant allele.