Answer to Question 1
ANS: A
An imbalance exists in the rate of globin chain synthesis in the thalassemias, and this is the primary mechanism leading to anemia. A build-up of the globin chain is produced in excess, and this causes damage to the red cell. Erythroid hyperplasia is present in the bone marrow (ineffective erythropoiesis).
Answer to Question 2
ANS: A
The b globin chain is decreased to absent in b-thalassemia major; however, a globin chain synthesis is normal. Infants up until approximately 6 months of age have an elevated Hb F that does not require b chains. They become symptomatic after the g-to-b switch.