Answer the following questions in the spaces provided.

1			In the lab where Sonja works, an African-American husband and wife recently had their blood tested and were surprised to learn that each is heterozygous for sickle-cell hemoglobin. Because neither ever has had any symptoms of sickle-cell anemia nor known any close relatives with sickle cell anemia, they cannot understand how they could have a child with this life-threatening disease. What is the explanation for this?
2			As part of a routine complete blood count, a 35-year-old female patient's hematocrit was determined to be 38 percent and her hemoglobin concentration was measured at 10 g/dL. What diagnosis is likely? Why?
3			An apparently healthy male patient, age 44, has a hemoglobin concentration of 28 g/dL. Why should you suspect that this reading is incorrect? What might be the cause?
4			Josh and Mark just started working in the same lab together, and they are having an argument about how to read hematocrits. Josh says that you should not include the "white part," while Mark says everything but the "watery part" should be included. Who is right? Why?
5			When Alberto centrifuged two capillary tubes of blood from the same newborn patient for a hematocrit reading, one tube gave a result of 50 percent and the other gave a result of 56 percent. Should Alberto consider these results close enough to be in agreement? Why or why not?