AAB MT Hematology Exam Questions
with correct Answers
What is hemoglobin composed of? - Answer- 4 heme, 4 iron, 4 globins
What disorder does a defect in heme synthesis lead to? - Answer- Porphyria
Porphyria - Answer- 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? - Answer- 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? - Answer- To keep iron in the ferrous state
What product is formed when ferrous iron of hemoglobin is oxidized to the ferric state? -
Answer- Methemoglobin
What is carboxyhemoglobin? - Answer- 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? - Answer- Carboxyhemoglobin
Which hemoglobin derivative causes irreversible changes in RBCs? - Answer-
Sulfhemoglobin -- makes blood incapable of carrying oxygen.
Which of the following hemoglobins is NOT normally present in a normal adult? -
Answer- Hb-S
Which embryonic hemoglobin is normally found in newborns? - Answer- Hb-F
What is the most abundant hemoglobin in a newborn? - Answer- Hb-F
What is the molecular structure of Hemoglobin S? - Answer- Valine replaces glutamic
acid in the 6th position of the beta chain
,Which of the following hemoglobins is insoluble under lowered oxygen tension? -
Answer- Hb-S
What laboratory test is used to confirm the specific diagnosis of sickle cell anemia? -
Answer- Hemoglobin electrophoresis
In the solubility test for hemoglobin S, what is the reagent responsible for the reduction
of the hemoglobin molecule? - Answer- Sodium dithionite
In hemoglobin C, what replaces glutamic acid? - Answer- Lysine
Which red blood cell inclusion is characteristic of hemoglobin C disease? - Answer-
Rod-shaped crystals
What is hemoglobin F composed of? - Answer- 2 alpha and 2 gamma chains
Which hemoglobin is resistant to alkali denaturation? - Answer- Hb-F
Which hemoglobins are differentiated by the Kleihauer-Betke technique? - Answer- Hb-
A1 from Hb-F
What is the order of migration of hemoglobins, from fastest to slowest, on cellulose
acetate at pH 8.4? - Answer- A1, F, S, C
Why is citrate agar used when abnormal hemoglobins are identified on cellulose acetate
at pH 8.6? - Answer- It separates hemoglobin S from hemoglobin D
The cyanmethemoglobin method measures all hemoglobin pigments EXCEPT which
one? - Answer- Sulfhemoglobin
What is the diluent used in the cyanmethemoglobin method for the determination of
hemoglobin? - Answer- Drabkin's solution
What is the normal plasma hemoglobin concentration? - Answer- 2-3 mg/dL
Which plasma protein binds free hemoglobin? - Answer- Haptoglobin
Which one of the following statements concerning hemolytic anemia is false? - Answer-
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. - Answer- Hemolytic
anemia
Myoglobin can be separated from hemoglobin by saturating the specimen with which
one of the following reagents? - Answer- Ammonium sulfite
, The hematocrit is also known as which one of the following terms? - Answer- Packed
red blood cell volume
The degree of packing of cells during centrifugation depends on all of the following
EXCEPT which one? - Answer- Bore size of the microhematocrit tube
The degree of packing of cells during centrifugation depends on all of the following: -
Answer- Speed of the centrifugation, radius of centrifugation, and time of centrifugation.
During examination of a spun hematocrit, in which layer are the white blood cells found?
- Answer- Buffy coat
When performing a microhematocrit, where should one read the percentage of packed
red blood cell column from a microhematocrit reading device? - Answer- Below the buffy
coat
An increase in the erythrocyte sedimentation rate can be the result of an increase in the
quantity of which of the following? - Answer- Fibrinogen
Which test is increased in acute infections? - Answer- Osmotic fragility
All of the following sources of error will falsely elevate the ESR EXCEPT which one? -
Answer- Polycythemia
All of the following sources of error will falsely elevate the ESR? - Answer- Tilted tube,
macrocytes, and vibrations from a nearby centrifuge.
What is the Westergren ESR reference range for males? - Answer- 0-15 mm/hr
A cerebrospinal fluid has 285 RBCs counted in the 5 RBC squares after being diluted in
a Unopette (1:100). What is the calculated RBC count per microliter? - Answer-
1,425,000 (285 x 100 x 5)
Any cell that passes through the aperture will momentarily increase the resistance of the
electrical flow between the electrodes, generating a pulse. This is the basic principle of
which of the following? - Answer- Electrical impedance
Which principle utilizes laminar flow and hydrodynamic focusing to characterize cells
based on granularity and reflectivity? - Answer- Laser light scatter
Scatterplots are created using all of the following EXCEPT which one? - Answer-
Fluorescence
Scatterplots are created using all of the following: - Answer- Scatter, volume, and
conductivity
with correct Answers
What is hemoglobin composed of? - Answer- 4 heme, 4 iron, 4 globins
What disorder does a defect in heme synthesis lead to? - Answer- Porphyria
Porphyria - Answer- 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? - Answer- 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? - Answer- To keep iron in the ferrous state
What product is formed when ferrous iron of hemoglobin is oxidized to the ferric state? -
Answer- Methemoglobin
What is carboxyhemoglobin? - Answer- 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? - Answer- Carboxyhemoglobin
Which hemoglobin derivative causes irreversible changes in RBCs? - Answer-
Sulfhemoglobin -- makes blood incapable of carrying oxygen.
Which of the following hemoglobins is NOT normally present in a normal adult? -
Answer- Hb-S
Which embryonic hemoglobin is normally found in newborns? - Answer- Hb-F
What is the most abundant hemoglobin in a newborn? - Answer- Hb-F
What is the molecular structure of Hemoglobin S? - Answer- Valine replaces glutamic
acid in the 6th position of the beta chain
,Which of the following hemoglobins is insoluble under lowered oxygen tension? -
Answer- Hb-S
What laboratory test is used to confirm the specific diagnosis of sickle cell anemia? -
Answer- Hemoglobin electrophoresis
In the solubility test for hemoglobin S, what is the reagent responsible for the reduction
of the hemoglobin molecule? - Answer- Sodium dithionite
In hemoglobin C, what replaces glutamic acid? - Answer- Lysine
Which red blood cell inclusion is characteristic of hemoglobin C disease? - Answer-
Rod-shaped crystals
What is hemoglobin F composed of? - Answer- 2 alpha and 2 gamma chains
Which hemoglobin is resistant to alkali denaturation? - Answer- Hb-F
Which hemoglobins are differentiated by the Kleihauer-Betke technique? - Answer- Hb-
A1 from Hb-F
What is the order of migration of hemoglobins, from fastest to slowest, on cellulose
acetate at pH 8.4? - Answer- A1, F, S, C
Why is citrate agar used when abnormal hemoglobins are identified on cellulose acetate
at pH 8.6? - Answer- It separates hemoglobin S from hemoglobin D
The cyanmethemoglobin method measures all hemoglobin pigments EXCEPT which
one? - Answer- Sulfhemoglobin
What is the diluent used in the cyanmethemoglobin method for the determination of
hemoglobin? - Answer- Drabkin's solution
What is the normal plasma hemoglobin concentration? - Answer- 2-3 mg/dL
Which plasma protein binds free hemoglobin? - Answer- Haptoglobin
Which one of the following statements concerning hemolytic anemia is false? - Answer-
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. - Answer- Hemolytic
anemia
Myoglobin can be separated from hemoglobin by saturating the specimen with which
one of the following reagents? - Answer- Ammonium sulfite
, The hematocrit is also known as which one of the following terms? - Answer- Packed
red blood cell volume
The degree of packing of cells during centrifugation depends on all of the following
EXCEPT which one? - Answer- Bore size of the microhematocrit tube
The degree of packing of cells during centrifugation depends on all of the following: -
Answer- Speed of the centrifugation, radius of centrifugation, and time of centrifugation.
During examination of a spun hematocrit, in which layer are the white blood cells found?
- Answer- Buffy coat
When performing a microhematocrit, where should one read the percentage of packed
red blood cell column from a microhematocrit reading device? - Answer- Below the buffy
coat
An increase in the erythrocyte sedimentation rate can be the result of an increase in the
quantity of which of the following? - Answer- Fibrinogen
Which test is increased in acute infections? - Answer- Osmotic fragility
All of the following sources of error will falsely elevate the ESR EXCEPT which one? -
Answer- Polycythemia
All of the following sources of error will falsely elevate the ESR? - Answer- Tilted tube,
macrocytes, and vibrations from a nearby centrifuge.
What is the Westergren ESR reference range for males? - Answer- 0-15 mm/hr
A cerebrospinal fluid has 285 RBCs counted in the 5 RBC squares after being diluted in
a Unopette (1:100). What is the calculated RBC count per microliter? - Answer-
1,425,000 (285 x 100 x 5)
Any cell that passes through the aperture will momentarily increase the resistance of the
electrical flow between the electrodes, generating a pulse. This is the basic principle of
which of the following? - Answer- Electrical impedance
Which principle utilizes laminar flow and hydrodynamic focusing to characterize cells
based on granularity and reflectivity? - Answer- Laser light scatter
Scatterplots are created using all of the following EXCEPT which one? - Answer-
Fluorescence
Scatterplots are created using all of the following: - Answer- Scatter, volume, and
conductivity
