An inherited disease that occurs almost exclusively in males and in which the blood is unable to clot is known as which condition?

• A. Hemophilia
• B. Sickle cell anemia
• C. Thrombocytopenia
• D. Leukemia

Answer: (A)

This question hinges on recognizing an inherited bleeding disorder that mostly affects males due to a genetic pattern on the X chromosome and leads to a failure of normal blood clotting. Hemophilia fits because it is typically inherited in an X-linked recessive way—males have one X chromosome, so a single faulty X results in the disease, while females usually are carriers and are less often affected. The defining problem is a deficiency or dysfunction of clotting factors in the blood, which prevents proper clot formation and causes prolonged bleeding after injuries or spontaneous bleeding, especially into joints.

In Hemophilia A, Factor VIII is missing or defective; in Hemophilia B, Factor IX is. This contrasts with the other conditions listed: sickle cell anemia affects red blood cells and is not limited to males, thrombocytopenia involves low platelets and can have many causes, and leukemia is a cancer of blood-forming cells with a different set of symptoms and inheritance patterns.