Question Detail
Question
If a human baby boy inherits a recessive allele from his mother, in which circumstance would he most likely show the trait coded for by the recessive allele? a. The allele is on the Y chromosome. b. The baby inherits the dominant allele from his father. c. The allele is on the X chromosome. d. The allele is on an autosomal chromosome and the baby is a twin.
Correct Answer
Option C is the correct answer.
Detailed Explanation
A baby boy has one X chromosome (from mother) and one Y (from father). If he inherits a recessive allele on the X chromosome from his mother, and the Y chromosome lacks the corresponding gene, he will express that trait because there is no dominant allele to mask it. This is X-linked recessive inheritance.
Hint
Males are hemizygous for X-linked genes.