6

Question 1

Normal adult hemoglobin has

A. two alpha and two delta chains
B. three alpha and one beta chains
C. two alpha and two beta chains
D. two beta and two epsilon chains

Answer 1

C. two alpha and two beta chains

Question 2

The number of heme groups in a hemoglobin molecule is
A. 1
B. 2
C. 3
D. 4

Answer 2

D. 4

Question 3

Most defects in the hemoglobin molecule are related to

A. amino acid substitutions
B. diminished production of one of the polypeptide chains
C. homozygous A/A inheritance
D. either A or and B

Answer 3

D. either A or and B

Question 4

The correct molecular composition of hemoglobin is

A. four heme groups two α and two ß globin chains
B. four heme groups, four α globin chains
C. two heme groups, four ß globin chains
D. two heme groups, one α and one ß globin chains

Answer 4

A. four heme groups two α and two ß globin chains

Question 5

Increased amounts of 2,3-DPG _____ the oxygen affinity of the hemoglobin molecule.

A. increase
B. decrease
C. do not alter

Answer 5

B. decrease

Question 6

After a molecule of hemoglobin gains the first two oxygen molecules, the molecule

A. expels 2,3-DPG
B. has decreased oxygen affinity
C. becomes saturated with oxygen
D. adds a molecule of oxygen to an alpha chain

Answer 6

A. expels 2,3-DPG

Question 7

If normal adult (A1) and fetal hemoglobin F are compared, fetal hemoglobin has _____ affinity for oxygen.

A. less
B. the same
C. a greater

Answer 7

C. a greater

Question 8

Oxyhemoglobin is a _____ than deoxyhemoglobin.

A. weaker acid
B. stronger acid

Answer 8

B. stronger acid

Question 9

If a young male was preparing for olympic competition and had his blood drawn for the measurement of oxygen dissociation, his results would demonstrate

A. a shift to the right
B. a shift to the left
C. no deviation from a normal curve
D. no results could be recorded

Answer 9

A. a shift to the right

Question 10

In cases of chronic carboxyhemoglobin exposure, the patient’s oxygen dissociation curve would exhibit

A. a shift to the left
B. a shift to the right
C. decreased affinity for oxygen
D. a normal curve

Answer 10

A. a shift to the left

Question 11

Heme is synthesized predominantly in

A. the liver
B. the red bone marrow
C. the mature erythrocytes
D. both A and B

Answer 11

D. both A and B

Question 12

The upper limit of the reference range of hemoglobin in an adult male is

A. 10.5 to 12.0 g/dL
B. 12.5 to 14.0 g/dL
C. 13.5 to 15.0 g/dL
D. 14 to 18.0 g/dL

Answer 12

D. 14 to 18.0 g/dL

Question 13

When iron availability is depleted in a cell, the translational rates of ferritin mRNA is

A. increased oxygen affinity
B. decreased oxygen affinity
C. no effect on oxygen affinity
D. 2,3-DPG will enter the center cavity of the hemoglobin molecule

Answer 13

B. decreased oxygen affinity

Question 14

The protein responsible for the transport of iron in hemoglobin synthesis is

A. globin
B. transferrin
C. oxyhemoglobin
D. ferritin

Answer 14

B. transferrin

Question 15

If globin synthesis is insufficient in a person, iron accumulates in the cell as _____ aggregates.

A. transferrin
B. ferritin
C. albumin
D. heme

Answer 15

B. ferritin

Question 16

Questions 16 and 17: The initial condensation reaction in the synthesis of porphyrin preceding heme formation takes place in the (16) _____ and requires (17) _____.

16. A. liver
    B. spleen
    C. red bone marrow
    D. mitochondria
17. A. iron
    B. vitamin B6
    C. vitamin B12
    D. vitamin D

Answer 16

16. D. mitochondria
17. B. vitamin B6

Question 17

The final steps in heme synthesis, including the formation of protoporphyrin, take place in

A. a cell’s nucleus
B. a cell’s cytoplasm
C. the spleen
D. the mitochondria

Answer 17

D. the mitochondria

Question 18

The dark-staining granules in the red blood cells when a bone marrow smear stained with Prussian Blue stain is examined
represent a defect of

A. membrane development
B. hemoglobin synthesis
C. globulin synthesis
D. red blood cell aging

Answer 18

B. hemoglobin synthesis

Question 19

The child’s medical history and the appearance of dense, dark-staining particles in some of the red blood cells on a peripheral blood smear suggest a diagnosis of

A. iron deficiency anemia
B. malaria
C. ingestion of lead
D. sickle cell disease

Answer 19

C. ingestion of lead

Question 20

The major hemoglobin synthesized in the second trimester fetus is

A. A
B. F
C. A2
D. A1c

Answer 20

B. F

Question 21

Which of the following hemoglobin types is the major type present in a normal adult?

A. A
B. S
C. A2
D. A1c

Answer 21

A. A

Question 22

Hemoglobin A consists of

A. two alpha and two delta chains
B. zeta chains and either epsilon or gamma chains
C. two alpha and two beta chains
D. two alpha and two gamma chains

Answer 22

C. two alpha and two beta chains

Question 23

Hemoglobin A2 consists of

A. two alpha and two delta chains
B. zeta chains and either epsilon or gamma chains
C. two alpha and two beta chains
D. two alpha and two gamma chains

Answer 23

A. two alpha and two delta chains

Question 24

Hemoglobin F consists of

A. two alpha and two delta chains
B. zeta chains and either epsilon or gamma chains
C. two alpha and two beta chains
D. two alpha and two gamma chains

Answer 24

D. two alpha and two gamma chains

Question 25

Embryonic hemoglobin consists of A. two alpha and two delta chains B. zeta chains and either epsilon or gamma chains C. two alpha and two beta chains D. two alpha and two gamma chains

Answer 25

B. zeta chains and either epsilon or gamma chains

Question 26

In normal infants, fetal hemoglobin (hemoglobin F) persists until A. a few days after birth B. a few weeks after birth C. several months after birth D. adulthood

Answer 26

C. several months after birth

Question 27

After a man was found unconscious in his garage with the car motor running, he was transported to the emergency department. When blood was drawn for a complete blood count, the plasma was noted to be bright red. What kind of variant hemoglobin should be suspected? A. Hemoglobin F B. Hemoglobin A C. Methemoglobin D. Carboxyhemoglobin

Answer 27

D. Carboxyhemoglobin

Question 28

Heinz bodies are associated with A. hemoglobin F B. hemoglobin A C. sulfhemoglobin D. carboxyhemoglobin

Answer 28

C. sulfhemoglobin

Question 29

A characteristic of methemoglobin is that it is A. incapable of combining with oxygen B. incapable of combining with carbon dioxide C. susceptible to precipitation as Heinz bodies D. present in normal in vivo concentration of greater than 15%

Answer 29

A. incapable of combining with oxygen

Question 30

Altered solubility of the hemoglobin S molecule is due to A. substitution of a nonpolar amino acid residue for a polar residue near the surface of the chain B. substitution of a polar amino acid residue for a nonpolar residue near the surface of the chain C. replacement of glutamic acid amino acid residue at the sixth position on the β-globin chain by a lysine amino acid residue D. replacement of lysine amino acid residue at the sixth position on the β-globin chain by a glutamic acid amino acid residue

Answer 30

A. substitution of a nonpolar amino acid residue for a polar residue near the surface of the chain

Question 31

The sickle gene may commonly occur with hemoglobin____. A. C B. F C. Bart D. H

Answer 31

C. Bart

Question 32

The alkaline denaturation test detects the presence of hemoglobin A. A1C B. F C. C D. S

Answer 32

B. F

Question 33

The type of hemoglobin that is detectable with the Kleihauer-Betke test is A. A B. A2 C. F D. S

Answer 33

C. F

Question 34

The physical difference in the detectable type of hemoglobin in the Kleihauer-Betke test is that this form of hemoglobin A. resists denaturation in the procedure B. is denatured in the procedure C. lacks gamma globulin genes D. has a lower affinity for oxygen

Answer 34

A. resists denaturation in the procedure

Question 35

Cellulose acetate at pH 8.6 separates the hemoglobin fractions A. S B. H C. A D. both A and C

Answer 35

D. both A and C

Question 35

As the erythrocyte ages, A. the membrane becomes less flexible with loss of cell membrane B. cellular hemoglobin increases C. enzyme activity, particularly glycolysis, decreases D. all of the above

Answer 35

D. all of the above

Question 36

Erythrocytic catabolism produces the disassembling of hemoglobin followed by A. iron transported in the plasma by transferrin B. globin catabolized in the liver to amino acids and then entering the amino acid pool C. bilirubin formed from opened porphyrin ring and carried by plasma albumin to the liver, conjugated, and excreted in bile D. all of the above

Answer 36

D. all of the above

Question 37

Which of the following statements are true of the intravascular destruction of erythrocytes? A. It accounts for less than 10% of normal erythrocyte breakdown. B. Hemoglobin is released directly into blood. C. Alpha and beta dimers are bound to haptoglobin. D. All of the above.

Answer 37

D. All of the above.

Question 38

If a female patient is diagnosed with anemia and her follow-up assays indicate blood serum results of increased bilirubin and decreased haptoglobin with hemosiderin in her urinary sediment, what is the most probable diagnosis? A. Extravascular catabolism B. Intravascular catabolism C. Defective hemoglobin synthesis D. Thalassemia

Answer 38

B. Intravascular catabolism