Thomas suffers from a sex-linked blood-clotting disorder called hemophilia that is transmitted by a recessive gene.Neither his mother nor his father has ever shown symptoms of this disease.What can we conclude about the genetic makeup of John's parents?

Question

Quizplus · Accepted Answer

Since hemophilia is a sex-linked disorder, it is more likely that the mother is a carrier of the faulty gene on one of her X chromosomes. The father cannot be a carrier because he only has one X chromosome, so if he had the faulty gene he would definitely have the disease. Therefore, it is likely that the father does not have the faulty gene, and is not affected by hemophilia.

Thomas Suffers from a Sex-Linked Blood-Clotting Disorder Called Hemophilia That