B4M1 22-23

Question 1

Each hemoglobin molecule can bind reversibly with:
a. One atom of oxygen
b. One molecule of oxygen
c. Four molecules of oxygen
d. Two molecules of oxygen

Answer 1

c. Four molecules of oxygen

Question 2

Aspirin prevents platelet aggregation by inhibiting the action of:
a. PF 3
b. GpIb
c. Thromboxane A2
d. Gp IIbIIIa complex

Answer 2

c. Thromboxane A2

Question 3

Which step is found in both the intrinsic and extrinsic pathway for clotting
initiation?
a. activation of factor IX
b. activation of factor XII
c. activation of factor X
d. activation of factor XI

Answer 3

c. activation of factor X

Question 4

Which of the following reaction requires HMWF and prekallikrein?
a. activation of factor IX
b. activation of factor VIII
c. activation of factor XI
d. activation of factor XII

Answer 4

d. activation of factor XII

Question 5

A positive tourniquet test is found in:
a. Thrombocytosis, decreased fibrinogen, vascular purpura
b. Thrombocytosis, increased fibrinogen, vascular purpura
c. Thrombocytopenia, increased fibrinogen, vascular purpura
d. Thrombocytopenia, decreased fibrinogen, vascular purpura

Answer 5

d. Thrombocytopenia, decreased fibrinogen, vascular purpura

Question 6

A 15-year-old boy fell, and had a minor superficial wound on his knee. He was
curious and asked about the mechanism of platelet plug. Which of the following is
TRUE?
a. The platelet-plugging mechanism is extremely important for closing the
minute ruptures in very small blood vessels that occur many thousands of
times daily.
b. The ATP and thromboxane act on nearby platelets to activate them as well,
and the stickiness of these additional platelets causes them to adhere to the
originally activated platelet.
c. When platelets come in contact with a damaged vascular surface, the
platelets themselves gradually change their characteristics.
d. If the rent in a vessel wall is small, a blood clot in addition to the platelet
plug is required to stop the bleeding.

Answer 6

a. The platelet-plugging mechanism is extremely important for closing the
minute ruptures in very small blood vessels that occur many thousands of
times daily.

Question 7

Which among the following cells has a role in graft-versus-host reactions?
a. Monocytes
b. T cells
c. Neutrophils
d. B cells

Answer 7

b. T cells

Question 8

Which of the following best refers to the physical and chemical characteristics of
platelets?
a. They are capable of reproduction.
b. They are formed in the bone marrow from megakaryocytes.
c. They are large round or oval discs 10-14 micrometers in diameter.
d. They have nuclei.

Answer 8

b. They are formed in the bone marrow from megakaryocytes.

Question 9

From birth, hematopoiesis occurs primarily in which of the following?
a. Bone Marrow
b. Spleen
c. Thymus
d. Lymph nodes

Answer 9

a. Bone Marrow

Question 10

10.Carboxyhemoglobin is formed by
a. CO
b. HCO3
c. HCN
d. CO2

Answer 10

a. CO

Question 11

11.How does plasmin dissolve blood clots?
a. It hydrolyzes the peptide bonds located on the carboxyl side of lysines and
arginines in fibrin.
b. It recruits macrophages and NK cells towards the fibrin mesh thereafter
dissolving the clot with massive release of proteolytic enzymes.
c. It catalyzes the conversion of inactive plasminogen to active plasmin
thereafter breaking hydrogen bonds weaved through the fibrin network.
d. It breaks the disulfide bonds between fibrin threads.

Answer 11

a. It hydrolyzes the peptide bonds located on the carboxyl side of lysines and
arginines in fibrin.

Question 12

12.Which of the following has a biconcave disc with a central pale area which
gradually fades into a reddish-pink cytoplasm?
a. Rubricyte
b. Mature erythrocyte
c. Reticulocyte
d. Metarubricyte

Answer 12

b. Mature erythrocyte

Question 13

In the interpretation of the complete blood count, some of the parameters are
directly read from the instrument and some are derived by calculation. Which
among the following is considered as a calculated parameter of the CBC?
a. Mean corpuscular volume
b. White blood cell
c. Hematocrit
d. Red blood cell

Answer 13

a. Mean corpuscular volume
c. Hematocrit

Question 14

Which of these is primarily released from the primary granules of the neutrophils?
a. Heparin
b. Histamine
c. Major basic protein
d. Acid phosphatase

Answer 14

d. Acid phosphatase

Question 15

If a patient has a prolonged prothrombin time (PT), the patient is most likely
deficient in factor:
a. IV
b. III
c. VII
d. IX

Answer 15

c. VII

Question 16

The binding of oxygen to hemoglobin differs from the oxygen-binding behavior of
myoglobin because –
a. oxygen binding to hemoglobin is cooperative.
b. oxygen binding to myoglobin is cooperative.
c. hemoglobin is not an allosteric protein.
d. the oxygen-binding curve of hemoglobin is hyperbolic.

Answer 16

a. oxygen binding to hemoglobin is cooperative.

Question 17

Identify the cell pointed to at the center of the field:
a. Lymphocyte
b. Basophil
c. Eosinophil
d. Neutrophil

Answer 17

b. Basophil

Question 18

Jenna is a 1st year medical student attending her class in hematology. During her
review of the components of complete blood count, she was asked to identify which
part of the CBC refers to the ratio of the average volume of a red blood cell and is
derived from the hematocrit and red cell count. Which among the following
components best fits the description given?
a. Mean Corpuscular Volume
b. Mean Corpuscular Hemoglobin
c. Hemoglobin
d. Red Cell Distribution Width (RDW)

Answer 18

a. Mean Corpuscular Volume

Question 19

Which of the following is the rate limiting factor in causing blood coagulation?
a. thrombin formation
b. formation of prothrombin activator
c. activation of fibrin stabilizing factor
d. fibrin formation

Answer 19

b. formation of prothrombin activator

Question 20

From which of the following cells involved in leukopoiesis is basophil derived?
a. Lymphoblast
b. Myeloblast
c. Proerythroblast
d. Monoblast

Answer 20

b. Myeloblast

Question 21

Normal Range for Bleeding Time:
a. 10-12 seconds
b. 4-10 minutes
c. 25-35 seconds
d. 2-8 minutes

Answer 21

d. 2-8 minutes

Question 22

Which of the following play a role in humoral immunity?
a. macrophages
b. T lymphocytes
c. monocytes
d. B lymphocytes

Answer 22

d. B lymphocytes

Question 23

One of the following cells is the tissue counterpart of monocytes:
a. myeloblast
b. monoblast
c. promonocyte
d. macrophage

Answer 23

d. macrophage

Question 24

A 28-year old pregnant female undergoes laboratory testing prior to childbirth.
What is the expected Complete Blood Count (CBC) finding?
a. Eosinophilia
b. Neutrophilia
c. Monocytosis
d. Lymphocytosis

Answer 24

b. Neutrophilia

Question 25

Which of the following is TRUE about T cells? a. They mature within the bone marrow. b. They produce antibodies. c. They transform into plasma cells. d. They are involved in cell-mediated immunity.

Answer 25

d. They are involved in cell-mediated immunity.

Question 26

Bohr effect, the binding of oxygen to hemoglobin is – a. decreased by the presence of H+ and CO2. b. increased by the presence of H+ and CO2. c. decreased by the presence of Na+. d. increased by the presence of Na+.

Answer 26

a. decreased by the presence of H+ and CO2.

Question 27

Which one of the following statements concerning the hemoglobin is correct? a. HbA1c differs from HbA by a single, genetically determined amino acid substitution. b. HbA is the most abundant hemoglobin in normal adults. c. The globin chain composition of HbF is α2δ2. d. Fetal blood has a lower affinity for oxygen than does adult blood because HbF has an increased affinity for 2,3-biphosphoglycerate.

Answer 27

b. HbA is the most abundant hemoglobin in normal adults.

Question 28

Which of the following causes polymerization of fibrinogen molecule into fibrin fibers? a. Prothrombin b. Thrombin c. Prothrombin activator d. Fibrin-stabilizing factor

Answer 28

b. Thrombin

Question 29

Neutrophilic leukocytosis may result from one of the following conditions: a. Rheumatoid Arthritis b. Lupus Erythematosus c. Vasculitis d. B12 Deficiency

Answer 29

a. Rheumatoid Arthritis c. Vasculitis

Question 30

Which of the following blood cells is the least mature? a. Monocytes b. Pluripotent hematopoietic stem cells c. Natural killer (NK) cells d. Segmented neutrophils

Answer 30

b. Pluripotent hematopoietic stem cells

Question 31

Approximately one-third of platelets are normally sequestered in the: a. Skin b. Spleen c. Lungs d. Kidneys

Answer 31

b. Spleen

Question 32

32.Protein C and its co-factors protein S proteolytically inactivate Factors: a. VIIa and Xa b. IXa and VIIa c. VIIIa and XIIIa d. Va and VIIIa

Answer 32

d. Va and VIIIa

Question 33

The test requires that an atraumatic subcutaneous incision be made without transecting vessels larger than subcutaneous capillaries. a. Clotting Time b. Bleeding Time c. Prothrombin Time d. Activated Partial Thromboplastin Timer

Answer 33

b. Bleeding Time

Question 34

34.This blood component functions as a solvent for carrying substances in the blood circulation and also absorbs heat. a. Plasma b. Proteins c. Water d. Electrolytes

Answer 34

a. Plasma c. Water

Question 35

A 22-year-old male, was brought to the ER due to a motor vehicular accident. On examination, a blood vessel was ruptured and after a while, it was noted to be contracting, causing instantaneous reduction of blood flow from the vessel. Which mechanism involved in hemostasis is likely involved here? a. Conversion of prothrombin to thrombin b. Formation of blood clot c. Platelet plug formation d. Vascular constriction

Answer 35

d. Vascular constriction

Question 36

A 44-year-old female presented in the ER with cough, progressive shortness of breath, night sweats, and weight loss. CXR showed Pulmonary tuberculosis. Which of the following cells will increase in number? a. monocytes b. erythrocytes c. platelets d. eosinophils

Answer 36

a. monocytes

Question 37

Genetically engineered tissue plasminogen activator is particularly helpful in which scenario? a. Hemodialysis patients being hooked to an artificial kidney machine b. Coronary artery thrombi occlusion c. Prevention of stroke in patients with abnormal heart rhythms d. Prevention of clots in heart lung machine during coronary bypass

Answer 37

b. Coronary artery thrombi occlusion

Question 38

Which of the following is an important function of the plasmin system? a. Acts as an anticoagulant b. Maintains capillary integrity c. Removes minor clots from millions of peripheral blood vessels d. Activates coagulation factors

Answer 38

c. Removes minor clots from millions of peripheral blood vessels

Question 39

It is the end product formed during activation of plasminogen which is a plasma protein. a. Fibrinogen b. Prothrombin c. Fibrinolysin d. Trypsin

Answer 39

c. Fibrinolysin

Question 40

Hemoglobin differs from myoglobin because: a. It does not contain any helical region b. It does not have a heme group c. It contains more β-pleated sheet structure d. It is a tetrameter, whereas myoglobin is a single polypeptide

Answer 40

d. It is a tetrameter, whereas myoglobin is a single polypeptide

Question 41

It is a crude measure of capillary fragility. a. Tourniquet Test b. Bleeding Time c. Prothrombin Time d. Clotting Time

Answer 41

a. Tourniquet Test

Question 42

When the eosinophil count exceeds the normal value, the patient most likely must be having: a. AIDS b. Stress and tension c. Parasitism d. Congenital immunodeficiency

Answer 42

c. Parasitism

Question 43

Which of the following plasma proteins is responsible for the maintenance of colloid osmotic pressure? a. Globulin b. Fibrinogen c. Albumin d. Prothrombin

Answer 43

a. Globulin c. Albumin

Question 44

Which of the following cellular structures is responsible for the package and release of the granules of the neutrophils? a. Golgi apparatus b. Mitochondria c. Nuclear membrane d. Lysosome

Answer 44

a. Golgi apparatus

Question 45

Which of the following is a known function of IgE that is bound in the surfaces of mast cells and basophils? a. Protects mucosae b. Phagocytic activation c. Activates complement d. Destroys parasitic worms

Answer 45

c. Activates complement d. Destroys parasitic worms

Question 46

Which of the following is the earliest recognizable erythroid precursor and is the largest of the erythroid precursors? a. Orthochromatic Normoblast b. Polychromatophilic Normoblast c. Basophilic Normoblast d. Pronormoblast

Answer 46

d. Pronormoblast

Question 47

The cyclic compounds which are linked by methylene (methine) bridges that make up the ring system within the red blood cells: a. Pyridine b. Proline c. Porphyrin d. Pyrrole

Answer 47

c. Porphyrin

Question 48

It maintains the integrity of blood vessels and form hemostatic plugs. a. Hemoglobin b. Platelet c. Red blood cell d. White blood cell

Answer 48

b. Platelet

Question 49

Vasoconstriction, as an initial event in hemostasis, is caused by several regulatory molecules which include: a. Fibrinogen and vWF b. Thromboxane A2 and serotonin c. Collagen and actin/myosin d. ADP and epinephrine

Answer 49

b. Thromboxane A2 and serotonin