AAB MT Hematology Exam 2025 With
100% Correct Answers
What is hemoglobin composed of? - correct answers ✔✔4 heme, 4 iron, 4 globins
What disorder does a defect in heme synthesis lead to? - correct answers ✔✔Porphyria
Porphyria - correct answers ✔✔Deficiency in the enzymes of the porphyrin pathway leads to
insufficient production of heme. The principal problem in these deficiencies is the accumulation
of porphyrins, the heme precursors, which are toxic to tissue in high concentrations.
What is methemoglobin? - correct answers ✔✔Methemoglobin is a form of hemoglobin that
contains ferric [Fe3+] iron and has a decreased ability to bind oxygen. However, the ferric iron
has an increased affinity for bound oxygen. When methemoglobin concentration is elevated in
red blood cells, tissue hypoxia can occur.
What is the function of the enzyme methemoglobin-cytochrome C reductase in a red blood
cell? - correct answers ✔✔To keep iron in the ferrous state
What product is formed when ferrous iron of hemoglobin is oxidized to the ferric state? -
correct answers ✔✔Methemoglobin
What is carboxyhemoglobin? - correct answers ✔✔A stable complex of carbon monoxide and
hemoglobin that forms in RBCs when carbon monoxide is inhaled or produced in normal
metabolism. Large quantities of it hinder delivery of O2 to the body. Tobacco smoking (through
carbon monoxide inhalation) raises the blood levels of COHb by a factor of several times from
its normal concentrations.
,Which hemoglobin has a 200 times greater binding capacity for the hemoglobin molecule than
oxygen? - correct answers ✔✔Carboxyhemoglobin
Which hemoglobin derivative causes irreversible changes in RBCs? - correct answers
✔✔Sulfhemoglobin -- makes blood incapable of carrying oxygen.
Which of the following hemoglobins is NOT normally present in a normal adult? - correct
answers ✔✔Hb-S
Which embryonic hemoglobin is normally found in newborns? - correct answers ✔✔Hb-F
What is the most abundant hemoglobin in a newborn? - correct answers ✔✔Hb-F
What is the molecular structure of Hemoglobin S? - correct answers ✔✔Valine replaces
glutamic acid in the 6th position of the beta chain
Which of the following hemoglobins is insoluble under lowered oxygen tension? - correct
answers ✔✔Hb-S
What laboratory test is used to confirm the specific diagnosis of sickle cell anemia? - correct
answers ✔✔Hemoglobin electrophoresis
In the solubility test for hemoglobin S, what is the reagent responsible for the reduction of the
hemoglobin molecule? - correct answers ✔✔Sodium dithionite
In hemoglobin C, what replaces glutamic acid? - correct answers ✔✔Lysine
Which red blood cell inclusion is characteristic of hemoglobin C disease? - correct answers
✔✔Rod-shaped crystals
, What is hemoglobin F composed of? - correct answers ✔✔2 alpha and 2 gamma chains
Which hemoglobin is resistant to alkali denaturation? - correct answers ✔✔Hb-F
Which hemoglobins are differentiated by the Kleihauer-Betke technique? - correct answers
✔✔Hb-A1 from Hb-F
What is the order of migration of hemoglobins, from fastest to slowest, on cellulose acetate at
pH 8.4? - correct answers ✔✔A1, F, S, C
Why is citrate agar used when abnormal hemoglobins are identified on cellulose acetate at pH
8.6? - correct answers ✔✔It separates hemoglobin S from hemoglobin D
The cyanmethemoglobin method measures all hemoglobin pigments EXCEPT which one? -
correct answers ✔✔Sulfhemoglobin
What is the diluent used in the cyanmethemoglobin method for the determination of
hemoglobin? - correct answers ✔✔Drabkin's solution
What is the normal plasma hemoglobin concentration? - correct answers ✔✔2-3 mg/dL
Which plasma protein binds free hemoglobin? - correct answers ✔✔Haptoglobin
Which one of the following statements concerning hemolytic anemia is false? - correct answers
✔✔The serum haptoglobin is increased
100% Correct Answers
What is hemoglobin composed of? - correct answers ✔✔4 heme, 4 iron, 4 globins
What disorder does a defect in heme synthesis lead to? - correct answers ✔✔Porphyria
Porphyria - correct answers ✔✔Deficiency in the enzymes of the porphyrin pathway leads to
insufficient production of heme. The principal problem in these deficiencies is the accumulation
of porphyrins, the heme precursors, which are toxic to tissue in high concentrations.
What is methemoglobin? - correct answers ✔✔Methemoglobin is a form of hemoglobin that
contains ferric [Fe3+] iron and has a decreased ability to bind oxygen. However, the ferric iron
has an increased affinity for bound oxygen. When methemoglobin concentration is elevated in
red blood cells, tissue hypoxia can occur.
What is the function of the enzyme methemoglobin-cytochrome C reductase in a red blood
cell? - correct answers ✔✔To keep iron in the ferrous state
What product is formed when ferrous iron of hemoglobin is oxidized to the ferric state? -
correct answers ✔✔Methemoglobin
What is carboxyhemoglobin? - correct answers ✔✔A stable complex of carbon monoxide and
hemoglobin that forms in RBCs when carbon monoxide is inhaled or produced in normal
metabolism. Large quantities of it hinder delivery of O2 to the body. Tobacco smoking (through
carbon monoxide inhalation) raises the blood levels of COHb by a factor of several times from
its normal concentrations.
,Which hemoglobin has a 200 times greater binding capacity for the hemoglobin molecule than
oxygen? - correct answers ✔✔Carboxyhemoglobin
Which hemoglobin derivative causes irreversible changes in RBCs? - correct answers
✔✔Sulfhemoglobin -- makes blood incapable of carrying oxygen.
Which of the following hemoglobins is NOT normally present in a normal adult? - correct
answers ✔✔Hb-S
Which embryonic hemoglobin is normally found in newborns? - correct answers ✔✔Hb-F
What is the most abundant hemoglobin in a newborn? - correct answers ✔✔Hb-F
What is the molecular structure of Hemoglobin S? - correct answers ✔✔Valine replaces
glutamic acid in the 6th position of the beta chain
Which of the following hemoglobins is insoluble under lowered oxygen tension? - correct
answers ✔✔Hb-S
What laboratory test is used to confirm the specific diagnosis of sickle cell anemia? - correct
answers ✔✔Hemoglobin electrophoresis
In the solubility test for hemoglobin S, what is the reagent responsible for the reduction of the
hemoglobin molecule? - correct answers ✔✔Sodium dithionite
In hemoglobin C, what replaces glutamic acid? - correct answers ✔✔Lysine
Which red blood cell inclusion is characteristic of hemoglobin C disease? - correct answers
✔✔Rod-shaped crystals
, What is hemoglobin F composed of? - correct answers ✔✔2 alpha and 2 gamma chains
Which hemoglobin is resistant to alkali denaturation? - correct answers ✔✔Hb-F
Which hemoglobins are differentiated by the Kleihauer-Betke technique? - correct answers
✔✔Hb-A1 from Hb-F
What is the order of migration of hemoglobins, from fastest to slowest, on cellulose acetate at
pH 8.4? - correct answers ✔✔A1, F, S, C
Why is citrate agar used when abnormal hemoglobins are identified on cellulose acetate at pH
8.6? - correct answers ✔✔It separates hemoglobin S from hemoglobin D
The cyanmethemoglobin method measures all hemoglobin pigments EXCEPT which one? -
correct answers ✔✔Sulfhemoglobin
What is the diluent used in the cyanmethemoglobin method for the determination of
hemoglobin? - correct answers ✔✔Drabkin's solution
What is the normal plasma hemoglobin concentration? - correct answers ✔✔2-3 mg/dL
Which plasma protein binds free hemoglobin? - correct answers ✔✔Haptoglobin
Which one of the following statements concerning hemolytic anemia is false? - correct answers
✔✔The serum haptoglobin is increased
