AAB MT Hematology (Questions And Answers To
Review For The AAB MT Exam)
What is hemoglobin composed of? Correct Ans - 4 heme, 4 iron, 4
globins
What disorder does a defect in heme synthesis lead to? Correct Ans -
Porphyria
Porphyria Correct Ans - 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 Ans - 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 Ans - To keep iron in the ferrous state
What product is formed when ferrous iron of hemoglobin is oxidized to the
ferric state? Correct Ans - Methemoglobin
What is carboxyhemoglobin? Correct Ans - 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 Ans - Carboxyhemoglobin
Which hemoglobin derivative causes irreversible changes in RBCs?
Correct Ans - Sulfhemoglobin -- makes blood incapable of carrying oxygen.
,Which of the following hemoglobins is NOT normally present in a normal
adult? Correct Ans - Hb-S
Which embryonic hemoglobin is normally found in newborns? Correct
Ans - Hb-F
What is the most abundant hemoglobin in a newborn? Correct Ans -
Hb-F
What is the molecular structure of Hemoglobin S? Correct Ans - Valine
replaces glutamic acid in the 6th position of the beta chain
Which of the following hemoglobins is insoluble under lowered oxygen
tension? Correct Ans - Hb-S
What laboratory test is used to confirm the specific diagnosis of sickle cell
anemia? Correct Ans - Hemoglobin electrophoresis
In the solubility test for hemoglobin S, what is the reagent responsible for the
reduction of the hemoglobin molecule? Correct Ans - Sodium
dithionite
In hemoglobin C, what replaces glutamic acid? Correct Ans - Lysine
Which red blood cell inclusion is characteristic of hemoglobin C disease?
Correct Ans - Rod-shaped crystals
What is hemoglobin F composed of? Correct Ans - 2 alpha and 2
gamma chains
Which hemoglobin is resistant to alkali denaturation? Correct Ans -
Hb-F
Which hemoglobins are differentiated by the Kleihauer-Betke technique?
Correct Ans - 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 Ans - A1, F, S, C
, Why is citrate agar used when abnormal hemoglobins are identified on
cellulose acetate at pH 8.6? Correct Ans - It separates hemoglobin S
from hemoglobin D
The cyanmethemoglobin method measures all hemoglobin pigments EXCEPT
which one? Correct Ans - Sulfhemoglobin
What is the diluent used in the cyanmethemoglobin method for the
determination of hemoglobin? Correct Ans - Drabkin's solution
What is the normal plasma hemoglobin concentration? Correct Ans -
2-3 mg/dL
Which plasma protein binds free hemoglobin? Correct Ans -
Haptoglobin
Which one of the following statements concerning hemolytic anemia is false?
Correct Ans - The serum haptoglobin is increased
In this type of anemia RBCs are normocytic and normochromic. RBCs,
hemoglobin, and hematocrit are decreased and the indirect bilirubin is
increased. Correct Ans - Hemolytic anemia
Myoglobin can be separated from hemoglobin by saturating the specimen
with which one of the following reagents? Correct Ans - Ammonium
sulfite
The hematocrit is also known as which one of the following terms?
Correct Ans - Packed red blood cell volume
The degree of packing of cells during centrifugation depends on all of the
following EXCEPT which one? Correct Ans - Bore size of the
microhematocrit tube
The degree of packing of cells during centrifugation depends on all of the
following: Correct Ans - Speed of the centrifugation, radius of
centrifugation, and time of centrifugation.
Review For The AAB MT Exam)
What is hemoglobin composed of? Correct Ans - 4 heme, 4 iron, 4
globins
What disorder does a defect in heme synthesis lead to? Correct Ans -
Porphyria
Porphyria Correct Ans - 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 Ans - 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 Ans - To keep iron in the ferrous state
What product is formed when ferrous iron of hemoglobin is oxidized to the
ferric state? Correct Ans - Methemoglobin
What is carboxyhemoglobin? Correct Ans - 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 Ans - Carboxyhemoglobin
Which hemoglobin derivative causes irreversible changes in RBCs?
Correct Ans - Sulfhemoglobin -- makes blood incapable of carrying oxygen.
,Which of the following hemoglobins is NOT normally present in a normal
adult? Correct Ans - Hb-S
Which embryonic hemoglobin is normally found in newborns? Correct
Ans - Hb-F
What is the most abundant hemoglobin in a newborn? Correct Ans -
Hb-F
What is the molecular structure of Hemoglobin S? Correct Ans - Valine
replaces glutamic acid in the 6th position of the beta chain
Which of the following hemoglobins is insoluble under lowered oxygen
tension? Correct Ans - Hb-S
What laboratory test is used to confirm the specific diagnosis of sickle cell
anemia? Correct Ans - Hemoglobin electrophoresis
In the solubility test for hemoglobin S, what is the reagent responsible for the
reduction of the hemoglobin molecule? Correct Ans - Sodium
dithionite
In hemoglobin C, what replaces glutamic acid? Correct Ans - Lysine
Which red blood cell inclusion is characteristic of hemoglobin C disease?
Correct Ans - Rod-shaped crystals
What is hemoglobin F composed of? Correct Ans - 2 alpha and 2
gamma chains
Which hemoglobin is resistant to alkali denaturation? Correct Ans -
Hb-F
Which hemoglobins are differentiated by the Kleihauer-Betke technique?
Correct Ans - 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 Ans - A1, F, S, C
, Why is citrate agar used when abnormal hemoglobins are identified on
cellulose acetate at pH 8.6? Correct Ans - It separates hemoglobin S
from hemoglobin D
The cyanmethemoglobin method measures all hemoglobin pigments EXCEPT
which one? Correct Ans - Sulfhemoglobin
What is the diluent used in the cyanmethemoglobin method for the
determination of hemoglobin? Correct Ans - Drabkin's solution
What is the normal plasma hemoglobin concentration? Correct Ans -
2-3 mg/dL
Which plasma protein binds free hemoglobin? Correct Ans -
Haptoglobin
Which one of the following statements concerning hemolytic anemia is false?
Correct Ans - The serum haptoglobin is increased
In this type of anemia RBCs are normocytic and normochromic. RBCs,
hemoglobin, and hematocrit are decreased and the indirect bilirubin is
increased. Correct Ans - Hemolytic anemia
Myoglobin can be separated from hemoglobin by saturating the specimen
with which one of the following reagents? Correct Ans - Ammonium
sulfite
The hematocrit is also known as which one of the following terms?
Correct Ans - Packed red blood cell volume
The degree of packing of cells during centrifugation depends on all of the
following EXCEPT which one? Correct Ans - Bore size of the
microhematocrit tube
The degree of packing of cells during centrifugation depends on all of the
following: Correct Ans - Speed of the centrifugation, radius of
centrifugation, and time of centrifugation.
