Multiple choice question (RT)

Question 2

CHAPTER 1

Which of the following lamps provides a continuous spectrum of radiant energy in the visible, near IR, and near UV regions of the spectrum:

1. tungsten-filament
2. hydrogen
3. deuterium
4. mercury vapor

Answer 2

1 - tungsten-filament

Question 3

Which of the following isolates light within a narrow region of the spectrum:

1. photomultiplier tube
2. monochromator
3. photovoltaic cell
4. detector

Answer 3

2 - monochromator

Question 4

Which of the following is not descriptive of a photomultiplier tube:

1. emits electrons proportionally to initial light absorbed
2. must be shielded from stray light
3. cannot be used with a chopper
4. amplifies the initial signal received

Answer 4

3 - cannot be used with a chopper

Question 5

Which of the following is false about a photomultiplier tube:

1. converts radiant energy (light) to electrical energy (current)
2. amplifies the current significantly
3. has a very rapid response time
4. is composed of an iron plate and a layer of selenium

Answer 5

4 - is composed of an iron plate and a layer of selenium

Question 6

Which type of photodetector employs a linear arrngement that allows it to respond to a specific wavelength resulting in complete UV/visible spectrum analysis:

1. photomultiplier tube
2. phototube
3. barrier layer cell
4. photodiode array

Answer 6

4 - photodiode array

Question 7

When performing spectrophotometer quality assurance checks, what is the holmium oxide glass filter used to assess:

1. linearity
2. stray light
3. absorbance accuracy
4. wavelength accuracy

Answer 7

4 - wavelength accuracy

Question 8

In spectrophotometric analysis, what is the purpose of the reagent blank:

1. correct for interfering chromogens
2. correct for lipemia
3. correct for protein
4. correct for color contribution of the reagents

Answer 8

4 - correct for color contribution of the reagents

Question 9

In regard to bichromatic analysis, which of the following is false:

1. absorbance is measured at the spectral absorbance peak for a blank and the sample using the same wavelength
2. eliminates background interferences
3. sample concentration determined from difference in two measured absorbances
4. functions as a reference blank for each sample

Answer 9

1 - absorbance is measured at the spectral absorbance peak for a blank and the sample using the same wavelength

Question 10

The bandpass of a spectrophotometer is 10nm. If an instrument is set at 540 nm, the wavelength that are permitted to impinge on the sample will be within what wavelength range:

1. 530-540 nm
2. 530-550 nm
3. 535-545 nm
4. 540-550 nm

Answer 10

3 - 535-545 nm

Question 11

Which of the following is not a problem inherent in turbidemetry:

1. variation in particle size of samples
2. variation in particle size of standards
3. rate of aggregation or settling of particles
4. need to maintain a constant and specific temperature

Answer 11

4 - need to maintain a constant and specific temperature

Question 12

Which of the following may be associated with reflectance spectrophotometry as it relates to the dry reagent slide technique:

1. light projected to the slide at 180 degree angle
2. dye concentration directly proportional to reflectance
3. unabsorbed, reflected light detected by photodetector
4. reflectance values are linearly proportional to transmission values

Answer 12

3 - unabsorbed, reflected light detected by photodetector

Question 13

Fluorometers are designed so that the path of the exciting light is at a right angler to the path of the emitted light. What is the purporse of this design:

1. prevent loss of emitted light
2. prevent loss of the excitation light
3. focus emitted and excitation light upon the detector
4. prevent excitation light from reaching the detector

Answer 13

4 - prevent excitation light from reaching the detector

Question 14

Which of the following represents a primary advantage of performing fluorometric over absorption spectroscopic methods of analysis:

1. increased specificity and increased sensitivity
2. increased specificity and decreased sensitivity
3. purity of reagents used not as critical
4. ease of performing assays

Answer 14

1 - increased specificity and increased sensitivity

Question 15

Which of the following may be associated with bioluminescence:

1. light emission produced due to enzymatic oxydation of a substrate
2. less sensitive than direct fluorescent assays
3. electron excitation caused by radiant energy
4. employs a radioactve label

Answer 15

1 - light emission produced due to enzymatic oxydation of a substrate

Question 16

Nephelometry is based on the measurement of light that is:

1. absorbed by particles in suspension
2. scattered by particles in suspension
3. produced by fluorescence
4. produced by excitation of ground-state atoms

Answer 16

2 - scattered by particles in suspension

Question 17

Which of the following instruments is used in the clinical laboratory or in reference laboratories to detect beta and gamma emissions:

1. fluorometer
2. nephelometer
3. scintillation counter
4. spectrophotometer

Answer 17

3 - scintillation counter

Question 18

Which of the following best describes chemiluminescence:

1. electron excitation caused by radiant energy
2. enzymatic oxidation of a substrate produces light emission
3. chemical energy excites electrons that emit light upon return to ground state
4. employs a fluorescent label that produces light

Answer 18

3 - chemical energy excites electrons that emit light upon return to ground state

Question 19

In assaying an analyte with a single-beam atomic absorption spectrophotometer, what is the instrument actually measuring:

1. intensity of light emitted by teh analyte on its return to the ground state
2. intesnity of light that the analyte absorbs from the hollow-cathode lamp
3. intensity of light that the analyte absorbs from the flame
4. intensity of the beam from the hollow-cathode lamp after it has passed through the analyte-containing flame

Answer 19

4 - intensity of the beam from the hollow-cathode lamp after it has passed through the analyte-containing flame

Question 20

What is the function of the flame in atomic absorption spectroscopy:

1. absorb the energy emitted from the metal analyte in returning to ground state
2. supply the thermal energy needed to excite the metal analyte
3. bring the metal analyte to its ground state
4. supply the light that is absorbed by the metal analyte

Answer 20

3 - bring the metal analyte to its ground state

Question 21

Most atomic absorption spectrophotometers incorporate a beam chopper and a tuned amplifier. The purpose of these components is to avoid errors that would be caused by:

1. variations in flame temperature
2. deterioration of the hollow-cathode lamp
3. stray light from the hollow-cathode lamp
4. measurement of light emitted by the analyte

Answer 21

4 - measurement of light emitted by the analyte

Question 22

In potentiometry, which of the following is considered the standard electrode:

1. hydrogen electrode
2. calcium electrode
3. potassium electrode
4. copper electrode

Answer 22

1 - hydrogen electrode

Question 23

In an electrolytic cell, which of the following is the half-cell where reduction takes place:

1. anode
2. cathode
3. combination electrode
4. electrode response

Answer 23

2 - cathode

Question 24

Mercury covered by a layer of mercurous chloride in contact with saturated potassium chloride solution is a description of which of the following types of electrodes:

1. sodium
2. calomel
3. calcium
4. silver/silver chloride

Answer 24

2 - calomel

Question 25

When a pH-sensitive glass electrode is not actively in use, in what type of solution should it be kept:

1. tap water
2. physiologic saline solution
3. the medium recommended by the manufacturer
4. a buffer solution of alkaline pH

Answer 25

3 - the medium recommended by the manufacturer

Question 26

When measuring K+ with an ion-selective electrode by means of a liquid ion-exchange membrane, what antibiotic will be incorporated into the membrane:

1. monactin
2. nonactin
3. streptomycin
4. valinomycin

Answer 26

4 - valinomycin

Question 27

Which of the following is false about ion-selective electrode analysis of sodium:

1. uses a glass membrane
2. errors occur from protein buildup on the membrane
3. membrane coated with valinomycin
4. principle based on potentiometry

Answer 27

3 - membrane coated with valinomycin

Question 28

What are the principles of operation for a chloride analyzer that generates silver ions as part of its reaction mechanism:

1. potentiometry and amperometry
2. amperometry and polarography
3. coulometry and potentiometry
4. amperometry and coulometry

Answer 28

4 - amperometry and coulometry

Question 29

When quantifying glucose using an amperometric glucose electrode system, which of the following is not a component of the system:

1. product oxidation produces a current
2. hydrogen peroxide formed
3. hexokinase reacts with glucose
4. platinum electrode

Answer 29

3 - hexokinase reacts with glucose

Question 30

To calibrate the pH electrode in a pH/blood gas analyzer, it is necessary that:

1. the barometric pressure be known and used for adjustments
2. calibrating gases of known high and low concentrations be used
3. the calibration be performed at room temperature
4. two buffer solutions of known pH be used

Answer 30

4 - two buffer solutions of known pH be used

Question 31

The measurement of CO2 in blood by means of a PCO2 electrode is dependent on the:

1. passage of H+ ions through the membrane that separates the sample and the electrode
2. change in pH because of increased carbonic acid in the electrolyte surrounding the electrodes
3. movement of bicarbonate across the membrane that separates the sample and the electrode
4. linear relationship between PCO2 in the sample and measured pH

Answer 31

2 - change in pH because of increased carbonic acid in the electrolyte surrounding the electrodes

Question 32

The measurement of oxygen in blood by means of a PO2 electrode involvs which of the following:

1. wheatstone bridge arrangement of resistive elements sensitive to oxygen concentration
2. direct relationship between amount of oxygen in the sample and amount of current flowing in the measuring system
3. change in current resulting from an increase of free silver ions in solution
4. glass electrode sensitive to H+ ions

Answer 32

2 - direct relationship between amount of oxygen in the sample and amount of current flowing in the measuring system

Question 33

Which of the following blood gas parameters are measured directly by the blood gas analyzer electrochemically as opposed to being calculated by the instrument:

1. pH, HCO3, total CO2
2. PCO2, HCO3, PO2
3. pH, PCO2, PO2
4. PO2, HCO3, total CO2

Answer 33

3 - pH, PCO2, PO2

Question 34

Which of the following statements is false about anodic stripping voltammetry (ASV):

1. based on peotentiometry
2. occurs in an electrochemical cell
3. involvs preconcentration of the analyte by electroplating
4. used to measure lead

Answer 34

1 - based on peotentiometry

Question 35

Which of the following methods allows for the separation of charged particles based on their rates of migration in an electric field:

1. rheophoresis
2. electrophoresis
3. electroendosmosis
4. ion exchange

Answer 35

2 - electrophoresis

Question 36

Which of the following techniques is based on electro-osmotic flow:

1. capillary electrophoresis
2. zone electrophoresis
3. iontophoresis
4. isoelectric focusing

Answer 36

1 - capillary electrophoresis

Question 37

Which of the following is not a type of support media used for serum protein electrophoresis:

1. agarose gel
2. cellulose acetate
3. acrylamide
4. celite

Answer 37

4 - celite

Question 38

In serum protein electrophoresis, when a buffer solution of pH 8.6 is used, which of the following characterized the proteins:

1. exhibit net negative charge
2. exhibit net positive charge
3. exhibit charge neutrality
4. migrate towards the cathode

Answer 38

1 - exhibit net negative charge

Question 39

Which of the following characteristics will a protein have at its isoelectric point:

1. net negative charge
2. net positive charge
3. net zero charge
4. mobility

Answer 39

3 - net zero charge

Question 40

What dye may be used for staining protein bands following electrophoresis:

1. fat red 7B
2. sudan black B
3. ponceau S
4. oil red O

Answer 40

3 - ponceau S

Question 41

When electrophoresis is performed, holes appear in the staining pattern, giving the stained protein band a doughnut-like appearance. What is the probable cause of this problem:

1. protein denatured and will not stain properly
2. ionic strength of the buffer was too high
3. protein reached its isoelectric point and precipitated out
4. protein concentration was too high

Answer 41

4 - protein concentration was too high

Question 42

What is the purporse of using ampholytes in isoelectric focusing:

1. maintain the polyacrylamide gel in a solid state
2. maintain the protein sample in a charged state
3. maintain the pH of the buffer solution
4. establish a pH gradient in the gel

Answer 42

4 - establish a pH gradient in the gel

Question 43

Which of the follwoing is not associated with silver stains:

1. reactive to nanogram concentrations of proteins
2. polypeptides stain a variety of colors
3. not as sensitive as Coomassie brilliant blue
4. preconcentration of CSF not necessary

Answer 43

3 - not as sensitive as Coomassie brilliant blue

Question 44

Which of the following is not associated with isoelectric focusing:

1. continuous pH gradient
2. migration of proteins with net charge of zero
3. seperation dependent on isoelectric point
4. zone electrohporesis

Answer 44

2 - migration of proteins with net charge of zero

Question 45

Which of the follwoing is an electrophoretic technique employing a pH gradient that separates molecules with similar isoelectric points:

1. zone electrophoresis
2. high-resolution electrophoresis
3. isoelectric focusing
4. immunoelectrophoresis

Answer 45

3 - isoelectric focusing

Question 46

To achieve the best levels of sensitivity and specificity, to what type of detector system could a gas chromatograph be coupled:

1. UV spectrophotometer
2. bichromatic spectrophotometer
3. mass spectrometer
4. fluorescence detector

Answer 46

3 - mass spectrometer

Question 47

Which of the following instruments has a sample-introduction system, solvent-delivery system, column, and detector as componants:

1. atomic absorption spectrometer
2. mass spectrometer
3. high-performance liquid chromatograph
4. nephelometer

Answer 47

3 - high-performance liquid chromatograph

Question 48

CHAPTER 2

What is the first type of cell produced by the developing embryo:

1. erythrocyte
2. granulocyte
3. lymphocyte
4. thrombocyte

Answer 48

1 - erythrocyte

Question 49

What percentage of tissue located in the bone marrow cavities of adults is fat:

1. 10%
2. 25%
3. 50%
4. 75%

Answer 49

3 - 50%

Question 50

Which of the following is not characteristic of pluripotent hematopoietic stem cells:

1. possess self-renewal ability
2. produce progenirtor cells committed to a single cell lineage
3. express the stem cell marker CD13
4. are morphologically unrecognizable

Answer 50

3 - express the stem cell marker CD13

Question 51

In an adult, what are the two best areas for obtaning active bone marrow by aspiration:

1. vertebra, tibia
2. sternum, vertebra
3. anterior iliac crest, tibia
4. posterior iliac crest, sternum

Answer 51

4 - posterior iliac crest, sternum

Question 52

What is the normal ratio of myeloid to erythroid precursors in bone marrow (M:E ratio):

1. 1:1
2. 1:3
3. 4:1
4. 8:1

Answer 52

3 - 4:1

Question 53

Which of the following does not accurately describe hematopoietic growth factors:

1. bind to target cell receptors to express activity
2. action of majority is lineage restricted
3. may promote or suprress cell death
4. can stimulate or inhibit cell proliferation

Answer 53

2 - action of majority is lineage restricted

Question 54

In the third month of gestation, what is the primary site of hematopoiesis:

1. liver
2. marrow of long bones
3. spleen
4. yolk sac

Answer 54

1 - liver

Question 55

The mechanism that relays information about tissue oxygen levels to erythropoietin-producing sites is located in the :

1. brain
2. kidney
3. liver
4. spleen

Answer 55

2 - kidney

Question 56

Antigen-independent lymphopoiesis occurs in primary lymphoid tissue located in the:

1. liver and kidney
2. spleen and lymph nodes
3. peyer’s patches and spleen
4. thymus and bone marrow

Answer 56

4 - thymus and bone marrow

Question 57

Programmed cell death is called:

1. necrosis
2. apoptosis
3. cellular senescence
4. terminal differentiation

Answer 57

2 - apoptosis

Question 58

In what area of the bone marrow does hematopoiesis take place:

1. cords
2. endosteum
3. endothelium
4. sinuses

Answer 58

1 - cords

Question 59

Bone marrow cellularity refers to the ratio of:

1. red cell precursors to white cell precursors
2. hematopoietic tissue to adipose tissue
3. granulocytic cells to erythrocytic cells
4. extravascular tissue to intravascular tissue

Answer 59

2 - hematopoietic tissue to adipose tissue

Question 60

Interleukins and colony stimulating factors are cytokines produced by:

1. B lymphocytes and erythrocytes
2. erythrocytes and thrombocytes
3. monocytes and T lymphocytes
4. neutrohpiles and monocytes

Answer 60

3 - monocytes and T lymphocytes

Question 61

What is the approximate total blood volume in an adult:

1. 1 L
2. 2L
3. 6L
4. 12L

Answer 61

3 - 6L

Question 62

The myeloid progenitor cell can produce cells committed to:

1. granulocytic, erythrocytic, monocytic, or megakaryocytic lineages
2. granuylocytic, monocytic, lymphocytic, or megakaryocytic lineages
3. erythrocytic, granulocytic, monocytic, or lymphocytic lineages
4. erythrocytic, granulocytic, lymphocytic, or megakaryocytic lineages

Answer 62

1 - granulocytic, erythrocytic, monocytic, or megakaryocytic lineages

Question 63

The largest hematopoietic cells in normal bone marrow are:

1. osteoblasts
2. osteoclasts
3. megakaryocytes
4. plasma cells

Answer 63

3 - megakaryocytes

Question 64

When evaluating a bone marrow aspirate smear, which finding is considered abnormal:

1. a predominance of granulocyte precursors as compared to nucleated red cells
2. detection of stainable iron in macrophages and erythroid precursors with Prussian blue
3. an average of three megakaryocytes seen per low power field
4. the presence of 10% myeloblasts on the cell differential count

Answer 64

4 - the presence of 10% myeloblasts on the cell differential count

Question 65

As most blood cell lines mature, which of the following is characteristic:

1. cell diameter increases
2. nucleus to cytoplasm ratio decreases
3. nuclear chromatin becomes less condensed
4. basophilia of the cytoplasm increases

Answer 65

2 - nucleus to cytoplasm ratio decreases

Question 66

Which of the following describes thrombopoietin (TPO):

1. renal hormone that regulates marrow red cell production
2. marrow hormone secreted by developing megakaryoblasts
3. hormone produced by the liver that stimulates megakaryopoiesis
4. pituitary hormone that controls platelet sequestration by the spleen

Answer 66

3 - hormone produced by the liver that stimulates megakaryopoiesis

Question 67

When the hepatic phase of fetal life is reactivated in an adult, hematopoliesis can be termed:

1. myeloid or medullary
2. myeloid metaplasia or extramedullary
3. myelophthisis or myelodysplasia
4. mesoblastic or mesenchymal

Answer 67

2 - myeloid metaplasia or extramedullary

Question 68

What is the average life span of a normal red blood cell:

1. 1 day
2. 10 days
3. 60 days
4. 120 days

Answer 68

4 - 120 days

Question 69

The Na+-K+ cation pump is an important mechanism in keeping the red blood cell intact. Its function is to maintain a high level of:

1. intracellulair Na+
2. intracellulair K+
3. plasma Na+
4. plasma K+

Answer 69

2 - intracellular K+

Question 70

Which of the following depicts the structure of the hemoglobin molecule:

1. two heme groups, two globin chains
2. four heme groups, two globin chains
3. two heme groups, four globin chains
4. four heme groups, four globin chains

Answer 70

4 - four heme groups, four globin chains

Question 71

Which of the following describes the process known as culling:

1. release of red cells from the bone marrow
2. binding of free hemoglobin by transport protein
3. incorporation of iron into protoporphyrin IX
4. removal of abnormal red cells by the spleen

Answer 71

4 - removal of abnormal red cells by the spleen

Question 72

Hemoglobin forms that are incapable of oxygen transport include:

1. deoxyhemoglobin and oxyhemoglobin
2. oxyhemoglobin and carboxyhemoglobin
3. carboxyhemoglobin and methemoglobin
4. methemoglobin and deoxyhemoglobin

Answer 72

3 - carboxyhemoglobin and methemoglobin

Question 73

The majortiy of iron found in an adult is a constituent of:

1. ferritin
2. myoglobin
3. hemoglobin
4. peroxidase

Answer 73

3 - hemoglobin

Question 74

A senescent red blood cell is one that has:

1. been hemolyzed
2. lived its life span
3. become deformed
4. lost its mitochondria

Answer 74

2 - lived its life span

Question 75

What red cell morphologic abnormality is described by the term poikilocytosis:

1. variations in size
2. deviations from normal shape
3. presence of inclusions
4. alterations in hemoglobin concentration

Answer 75

2 - deviations from normal shape

Question 76

Howell-Jolly bodies are composed of:

1. DNA
2. iron
3. reticulum
4. RNA

Answer 76

1 - DNA

Question 77

When spherocytes are reported, what is observed on the peripheral blood smear:

1. red cells without a central pallor
2. red cells with blunt projections
3. red cells with sharp projections
4. red cells with intracellulair rod-shaped crystals

Answer 77

1 - red cells without a central pallor

Question 78

The red cells found in lead poisoning characteristically exhibit coarse granules coposed of _________ that are reported as __________.

1. precipitated hemoglobin; pappenheimer bodies
2. aggregated ribosomes; basophilic stippling
3. nuclear fragments; pappenheimer bodies
4. excess iron deposits; basophilic stippling

Answer 78

2 - aggregated ribosomes; basophilic stippling

Question 79

Rouleaux of red blood cells when seen in the monolayer of a blood smear is characteristic of:

1. hyperplenism
2. hypogamamglobulinemia
3. cold hemagglutinin disease
4. multiple myeloma

Answer 79

4 - multiple myeloma

Question 80

Which of the following statements about iron absorption is true:

1. absorption occurs in the ileum
2. the mucosal cell always absorbs the correct amount of iron to meet needs
3. absorption increases when erythropoietic activity increases
4. alkaline pH favors absorption

Answer 80

3 - absorption increases when erythropoietic activity increases

Question 81

What term describes a mature red blood cell that contains iron granules or deposits:

1. siderosome
2. sideroblast
3. ringed sideroblast
4. siderocyte

Answer 81

4 - sideorocyte

Question 82

Which of the following is associated with a shift to the left in the oxygen dissociation curve of hemoglobin:

1. decreased pH and elevated temperature
2. decreased oxygen affinity
3. decreased oxygen release
4. presence of 2,3-biphosphoglycerate (2,3-BPG)

Answer 82

3 - decreased oxygen release

Question 83

Which of the following statements does not characterize erythropoietin (EPO):

1. transfroms the CFU-E into the earliest recognizable RBC precursor
2. increases the rate of red blood cell production by the bone marrow
3. shortens the maturation time of developing erythroid precursors
4. decreases stimulation of erythropoiesis when cellulair hypoxia increases

Answer 83

4 - decreases stimulation of erythropoiesis when cellulair hypoxia increases

Question 84

Which of the following factors will result in an immediate increase in oxygen delivery to the tissues:

1. increased pH
2. high altitudes
3. increased hemoglobin binding of 2,3-BPG
4. increased renal release of erythropoietin

Answer 84

3 - increased hemoglobin binding of 2,3-BPG

Question 85

Periods of intense erythropoietin activity cause premature release of marrow reticulocytes into the blood. Which of the following is not true of these early reticulocytes:

1. loss of residual RNA occurs immediately upon marrow release
2. circulate longer than usual before reaching maturity
3. may be termed shift or stress reticulocytes
4. show diffuse basophilia with Wright’s stain

Answer 85

1 - loss of residual RNA occurs immediately upon marrow release

Question 86

Which of the following inclusions is only visible with supravital staining:

1. basophilic stippling
2. cabot rings
3. heinz bodies
4. pappenheimer bodies

Answer 86

3 - heinz bodies

Question 87

The presence of schistocytes on the peripheral blood smear is commonly associated with:

1. increased iron mobilization
2. increased red cell destruction
3. decreased erythropoietin activity
4. decreased red cell proliferation

Answer 87

2 - increased red cell destruction

Question 88

Which of the following may be a sign of accelerated bone marrow erythropoiesis:

1. hypercellular marrow with a decreased number of RBC precursors
2. bone marrow M:E ratio of 6:1
3. nucleated red cells in the peripheral circulation
4. low erythrocyte, hemoglobin, and hematocrit levels

Answer 88

3 - nucleated red cells in the peripheral circulation

Question 89

Microcytic, hypochromic red cells are most often associated with impaired:

1. DNA synthesis
2. RNA metabolism
3. hemoglobin synthesis
4. enzyme metabolism

Answer 89

3 - hemoglobin synthesis

Question 90

When acanthocytes are found on the blood smear, it is usually the result of:

1. abnormal membrane permeability
2. altered membrane lipids
3. mechanical trauma
4. polymerization of hemoglobin molecules

Answer 90

2 - altered membrane lipids

Question 91

Which erythrocyte metabolic pathway generates adenosine triphosphate (ATP) via glycolysis:

1. embden-meyerhof
2. hexose monophosphate
3. rapoport-luebering
4. methemoglobin reductase

Answer 91

1 - embden-meyerhof

Question 92

Which of the following red blood cell precursors is the last stage to undergo mitosis:

1. pronormoblast
2. basophilic normoblast
3. polychromatophilic normoblast
4. orthochromic normoblast

Answer 92

3 - polychromatophilic normoblast

Question 93

The major adult hemoglobin requires the synthesis of alpha-globin chains and:

1. beta-globin chains
2. delta-globin chains
3. epsilon-globin chains
4. gamma-globin chains

Answer 93

1 - beta-globin chains

Question 94

Defective nuclear maturation commonly results in the production of red cells that are:

1. normocytic
2. hypochromic
3. macrocytic
4. microcytic

Answer 94

3 - macrocytic

Question 95

The major storage form of iron is:

1. ferritin
2. transferrin
3. hemosiderin
4. hemachromatin

Answer 95

1 - ferritin

Question 96

CHAPTER 3

The hemorrhagic problems associated with scurvey are due to a deficiency of __________, which is a cofactor required for collagen synthesis.

1. vitamin C
2. prothrombin
3. vitamin K
4. protein C

Answer 96

1 - vitamin C

Question 97

The number of platelets an average megakaryocyte generates is approximately:

1. 25-50
2. 50-200
3. 200-500
4. 2000-4000

Answer 97

4 - 2000-4000

Question 98

Which of the following is not a cause of thrombocytopenia:

1. splenomegaly
2. chemotherapy
3. increased thrombopoietin
4. aplastic anemia

Answer 98

3 - increased thrombopoietin

Question 99

Platelets interactiv with and binding to other platelets is referred to as:

1. adhesion
2. aggregation
3. release
4. retraction

Answer 99

2 - aggregation

Question 100

In platelet aggregation studies, certain aggregating agents induce a biphasic aggregation curve. This second phase of aggregation is directly related to:

1. formation of fibrin
2. changes in platelet shape
3. release of endogenous ADP
4. release of platelet factor 3

Answer 100

3 - release of endogenous ADP

Question 101

A platelet aggregation agent that characteristically yields a biphasic curve when used in optimal concentration is:

1. arachidonic acid
2. collagen
3. epinephrine
4. ristocetin

Answer 101

3 - epinephrine

Question 102

The operating principle of a platelet aggregometer is best described as:

1. aggregation on a foreign surface: platelet aggregation is directly proportional to the difference in platelet counts performed before and after platelet-rich plasma is passed through a column of glass beads
2. change in optical density: as platelets aggregate, the optical density of the platelet-rich plasma decreases
3. electrical impedance: platelet aggregates are counted as they pass through an aperature, temporarily interrupting the flow of current between two electrodes
4. pulse editing: editing electronically generated pusles can differentiate the number of free platelets versus platelet aggregates

Answer 102

2 - change in optical density: as platelets aggregate, the optical density of the platelet-rich plasma decreases

Question 103

Of the following therapeutic agents, those considered to be antiplatelet medications are:

1. aspirin and Plavix
2. Coumadin and heparin
3. heparin and protamine sulfate
4. tissue plasminogen activator and streptokinase

Answer 103

1 - aspirin and Plavix

Question 104

A potent inhibitor of platelet aggregation released by endothelial cells is:

1. epinephrine
2. prostacyclin
3. ristocetin
4. thromboxane A2

Answer 104

2 - prostacyclin

Question 105

The reference value for mean platelet volume (MPV) is approximately:

1. 2-4 fL
2. 5-7 fL
3. 8-10 fL
4. 11-14 fL

Answer 105

3 - 8-10 fL

Question 106

The platelet parameter PDW refers to the:

1. average platelet volume
2. cell weight versus density
3. capacity to adhere to foreign surfaces
4. variation in platelet cell size

Answer 106

4 - variation in platelet cell size

Question 107

A normal histogram showing platelet size distribution is best described as:

1. bimodal, nonskewed peaks
2. left-skewed single peak
3. right-skewed single peak
4. single peak, Gaussian distribution

Answer 107

3 - right-skewed single peak

Question 108

Which of the following is not a normal maturation stage for platelets:

1. megakaryoblast
2. promegakaryocyte
3. micromegakaryocyte
4. megakaryocyte

Answer 108

3 - micromegakaryocyte

Question 109

The recommended type of microscopy for the performance of manual platelet counts is:

1. electron
2. dark field
3. light
4. phase contrast

Answer 109

4 - phase contrast

Question 110

The size threshold range used by electrical impedance methods to count particles as platelets is:

1. 0-10 fL
2. 2-20 fL
3. 15-40 fL
4. 35-90 fL

Answer 110

2 - 2-20 fL

Question 111

In storage pool disease, platelets are primarily deficient in:

1. ADP
2. platelet factor 3
3. thrombasthenin
4. thromboxane A2

Answer 111

1 - ADP

Question 112

The anticoagulant required for routine coagulation testing is:

1. sodium heparin
2. sodium citrate
3. acid citrate dextrose
4. sodium fluoride

Answer 112

2 - sodium citrate

Question 113

Which of the following is not synthesized in the liver:

1. factor VIII
2. plasminogen
3. protein C
4. von Willebrand factor

Answer 113

4 - von Willebrand factor

Question 114

When thrombin binds to thrombomodulin on the endothelial cell surface, thrombin can:

1. activate the protein C pathway
2. activate factor V and factor VIII
3. convert fibrinogen to fibrin
4. stimulate platelet aggregation

Answer 114

1 - activate the protein C pathway

Question 115

The coagulation factors having a sex-linked recessive inheritance pattern are:

1. factor V and factor VIII
2. factor VIII and factor IX
3. factor IX and factor X
4. von Willebrand factor and factor VIII

Answer 115

2 - factor VIII and factor IX

Question 116

Prekallikrein deficiency is associated with:

1. prolonged aPTT that does not correct with a mixing study
2. autosomal dominant inheritance
3. increased risk of thrombosis
4. delayed bleeding at the incision site following surgery

Answer 116

3 - increased risk of thrombosis

Question 117

Which of the following will not cause the thrombin time to be prolonged:

1. fibrin degradation products
2. heparin
3. factor I deficiency
4. factor II deficiency

Answer 117

4 - factor II deficiency

Question 118

The expected screening test results for a patient with a fibrin stabilizing factor deficiency are:

1. prolonged prothrombin time
2. prolonged activated partial thromboplastin time
3. prolonged prothrombin time and activated partial thromboplastin time
4. normal prothrombin time and activated partial thromboplastin time

Answer 118

4 - normal prothrombin time and activated partial thromboplastin time

Question 119

A patient on therapeutic warfarin will most likely have a:

1. normal PT/INR, increased aPTT, prolonged bleeding time, low platelet count
2. increased PT/INR, increased aPTT, normal bleeding time, normal platelet count
3. normal PT/INR, normal aPTT, normal bleeding time, normal platelet count
4. increased PT/INR, normal aPTT, prolonged bleeding time, low platelet count

Answer 119

2 - increased PT/INR, increased aPTT, normal bleeding time, normal platelet count

Question 120

Which of the following complexes is not needed for blood coagulation to occur:

1. VIIa, tissue factor, Ca
2. IXa, VIII, Ca, PF3
3. Xa, V, Ca, PF3
4. XIIa, kallikrein, HMWK

Answer 120

4 - XIIa, kallikrein, HMWK

Question 121

von Willebrand factor is a:

1. phospholipid required for multiple reactions in the coagulation sequence
2. plasma protein that binds platelets to exposed subendothelial collagen
3. plasma protein with procoagulant activity in the intrisic coagulation system
4. platelet membrane glycoprotein that attaches the platelet to the injured vessel wall

Answer 121

2 - plasma protein that binds platelets to exposed subendothelial collagen

Question 122

Fibrin strands are cross-linked and the fibrin clot is stabilized by the activity of:

1. alpha2-antiplasmin
2. factor XIIIa
3. plasmin
4. thrombin

Answer 122

2 - factor XIIIa

Question 123

Which of the following does not contribute to the activation of the fibrinolytic system:

1. XIIa
2. XIa
3. kallikrein
4. tissue plasminogen activator

Answer 123

2 - XIa

Question 124

Which of the following enzymatically degrades the stabilized fibrin clot:

1. plasminogen
2. plasmin
3. prothrombin
4. thrombin

Answer 124

2 - plasmin

Question 125

The activity of the lupus anticoagulant and anticardiolipin antibodies appears to be directed against:

1. factor V
2. factor VIII
3. factor IX
4. phospholipid

Answer 125

4 - phospholipid

Question 126

Heparin inhibits clotting by:

1. chelating calcium ions
2. preventing activation of prothrombin
3. causing liver synthesis of nonfunctional factors
4. enhancing the action of antithrombin

Answer 126

4 - enhancing the action of antithrombin

Question 127

The main regulatory protein of secondary hemostasis is:

1. antithrombin
2. protein C
3. alpha2-antiplasmin
4. tissue plasminogen activator

Answer 127

1 - antithrombin

Question 128

Why is the activated partial thromboplastin time (aPTT) not the procedure of choice for detecting a platelet factor 3 (PF3) deficiency:

1. platelet-rich plasma is used for this test
2. the reagent contains a phospholipid substitute for PF3
3. PF3 is unstable in the reagent used for this test
4. PF3 does not function in the system being tested

Answer 128

2 - the reagent contains a phospholipid substitute for PF3

Question 129

Measurement of the time required for fibrin formation when thrombin is added to plasma evaluates the:

1. fibrinogen concentration
2. prothrombin concentration
3. extrinsic clotting system
4. intrinsic clotting system

Answer 129

1 - fibrinogen concentration

Question 130

Which of the following is not true of the international normalized ratio (INR):

1. INR is dependent on reagents and instrumentation used
2. INR is calculated using the PT ratio taken to the power of the ISI value
3. the world health organization recommends reporting the INR on patients on stable oral anticoagulant therapy
4. a therapeutic INR for a patient on Coumadin is between 2.0 and 3.0, but may be higher depending on the cause of the patient’s underlying disease state

Answer 130

1 - INR is dependent on reagents and instrumentation used

Question 131

A prolonged aPTT result is obtained on a patient diagnosed with acute disseminated intravascular coagulation (DIC). The patient has not yet been treated for this disorder. The most likely cause of the prolonged aPTT is:

1. in addition to DIC, the patient is deficient in a factor required for the extrinsic pathway
2. DIC is characterized by synthesis of less stable coagulation factors, which deteriorate rapidly in the circulation
3. systemic activation of the coagulation system depletes some factors more rapidly than the liver can synthesize them
4. the patient has been misdiagnosed; a prolonged aPTT indicates that the problem is deficient, not excessive, coagulation

Answer 131

3 - systemic activation of the coagulation system depletes some factors more rapidly than the liver can synthesize them

Question 132

Which of the following test results is not characteristic of DIC:

1. decreased fibrinogen concentration
2. positive test for degredation products
3. decreased platelet count
4. increased antithrombin

Answer 132

4 - increased antithrombin

Question 133

The principle of __________ methods depends on cleavage of synthetic substrates by an active serine protease:

1. chromogenic
2. photo-optical
3. mechanical
4. immunodiffusion

Answer 133

1 - chromogenic

Question 134

Epsilon aminocaproic acid is the treatment of choice for:

1. von Willebrand disease
2. hemophilia A
3. DIC with secondary fibrinolysis
4. primary fibrinogenolysis

Answer 134

4 - primary fibrinogenolysis

Question 135

A clot retraction defect is most likely due to:

1. lack of platelet receptor glycoprotein Ib
2. lack of platelet receptor glycoprotein IIb/IIIa
3. insufficient ADP in dense bodies
4. absence of von Willebrand factor

Answer 135

2 - lack of platelet receptor glycoprotein IIb/IIIa

Question 136

Thrombocytosis is a characteristic of:

1. disseminated intravascular coagulation:
2. splenomegaly
3. polycythemia vera
4. idiopathic thrombocytopenic purpura

Answer 136

3 - polycythemia vera

Question 137

In which of the following functions are the products released by vascular endothelial cells not involved:

1. inhibition of platelet aggregation
2. activation of the fibrinolytic system
3. conversion of thrombin from a procoagulant to an anticoagulant
4. cross-linkage of fibrin monomers

Answer 137

4 - cross-linkage of fibrin monomers

Question 138

If a physician suspects a qualitative platelet defect, the most useful test to order is the:

1. platelet count
2. prothrombin time
3. 5.0 M urea solubility test
4. bleeding time

Answer 138

4 - bleeding time

Question 139

The coagulation factors referred to as vitamin K-dependent are:

1. I, V, VIII, XIII
2. II, V, IX, XII
3. II, VII, IX, X
4. XI, XII, Fletcher, Fitzgerald

Answer 139

3 - II, VII, IX, X

Question 140

A patient on warfarin therapy will be deficient in a functional amount of:

1. fibrinogen and prothrombin
2. stable and labile factors
3. protein C and protein S
4. fletcher and fitzgerald factors

Answer 140

3 - protein C and protein S

Question 141

A 25-year-old male presents to his physician complaning of leg pain. The physician diagnoses a deep vein thrombosis and wants to determine the cause of the thrombotic episode. Which of the following conditions would not be associated with such a thrombotic episode:

1. factor V leiden and prothrombin 20210 mutations
2. hypofibrinogenemia and hyperhomocysteinemia
3. lupus anticoagulant and anticardiolipin antibodies
4. antithrombin and protein C deficiencies

Answer 141

2 - hypofibrinogenemia and hyperhomocysteinemia

Question 142

An 85-year-old male with slurred speech and paralysis on the right side of the body is seen in the emergency department. A stat D-dimer is ordered and is very high. The physician suspects a thromboembolic event based on the D-dimer, and needs to institue clot-dissolving therapy immediately. The most likely diagnosis and appropriate therapy for the patient is:

1. myocardial infarction; treat with aspirin
2. pulmonary embolism; treat with warfarin
3. deep vein thrombosis; treat with heparin
4. stroke; treat with tissue plasminogen activator

Answer 142

4 - stroke; treat with tissue plasminogen activator

Question 143

CHAPTER 4

A hapten is:

1. half of an immunoglobulin molecule
2. a carrier molecule for an antigen that is not antigenic alone
3. an immunoglobulin functional only in the presence of complement
4. a determinant capable of stimulating an immune response only when bound to a carrier

Answer 143

4 - a determinant capable of stimulating an immune response only when bound to a carrier

Question 144

Which of the following is characteristic of B cells:

1. phagocytic
2. participate in antibody-dependent cellular cytotoxicity (ADCC) reactions
3. contain surface immunoglobulins
4. secrete the C5 component of complement

Answer 144

3 - contain surface immunoglobulins

Question 145

A lymphokine is:

1. a soluble mediator produced by granulocytes and affecting lymphocytes
2. a soluble mediator produced by lymphocytes
3. a soluble mediator produced by plasma cells
4. an antibody that reacts with lymphocytes

Answer 145

2 - a soluble mediator produced by lymphocytes

Question 146

Monocytes and macrophages play a major role in the mononuclear phagocytic system. For an antibody-coated antigen to be phagocytized, what part of the antibody molecule fits into a receptor on the phagocytic cell:

1. Fc region
2. Fab region
3. Hinge region
4. variable region

Answer 146

1 - Fc region

Question 147

Cell-mediated immunity is primarily mediated by:

1. B cells
2. T helper cells
3. plasma cells
4. dendritic cells

Answer 147

2 - T helper cells

Question 148

The HLA complex is located primarily on:

1. chromosome 3
2. chromosome 6
3. chromosome 9
4. chromosome 17

Answer 148

2 - chromosome 6

Question 149

HLA antigens are found on:

1. all nucleated cells
2. red blood cells only
3. solid tissue only
4. white blood cells only

Answer 149

1 - all nucleated cells

Question 150

Which of the following is more likely to be diagnostic of an acute infection:

1. a total acute antibody titer of 2 followed by a convalescent titer of 16
2. a total acute antibody titer of 80 followed by a convalescent titer of 40
3. a total antibody titer of 80
4. an IgG antibody titer of 80

Answer 150

1 - a total acute antibody titer of 2 followed by a convalescent titer of 16

Question 151

A young woman shows increased susceptibility to pyogenic infections. Upon assay, she shows a low level of C3. Which of the following statements is probably true:

1. she has a autoimmune disease with continual antigen-antibody activity causing consumption of C3
2. she has DiGeorge syndrome
3. she has decreased production of C3
4. she may produce an inactive form of C2, a precursor of C3

Answer 151

3 - she has decreased production of C3

Question 152

What is the predominant type of antibody found in the serum of neonates born after full-term gestation:

1. infant IgA
2. infant IgG
3. infant IgM
4. maternal IgG

Answer 152

4 - maternal IgG

Question 153

An important part of the nonspecific immune response is:

1. B cells
2. basophils
3. complement cascade
4. cytotoxic T lymphocytes

Answer 153

3 - complement cascade

Question 154

The major class of immunoglobulin found in adult human serum is:

1. IgA
2. IgE
3. IgG
4. IgM

Answer 154

3 - IgG

Question 155

Which class of immunoglobulin possesses delta heavy chains:

1. IgA
2. IgD
3. IgE
4. IgG

Answer 155

2 - IgD

Question 156

Which class of immunoglobulin possesses 10 antigenic binding sites:

1. IgA
2. IgD
3. IgG
4. IgM

Answer 156

4 - IgM

Question 157

Which class of immunoglobulin binds to basophils and mast cells to mediate immediate hypersensitivy reactions:

1. IgA
2. IgD
3. IgE
4. IgG

Answer 157

3 - IgE

Question 158

Type I hypersensitivity is:

1. associated with complement-mediated cell lysis
2. due to immune complex deposition
3. mediated by activated macrophages
4. an immediate allergic reaction

Answer 158

4 - an immediate allergic reaction

Question 159

When performing the enzyme-multiplied immunoassay technique (EMIT), how is the ligand in the patient’s serum detected:

1. agglutinates by binding to antibody coated latex beads
2. binds to enzyme-labeled antibody
3. competes with enzyme-labeled antigen for binding to a specific antibody
4. forms antibody-antigen complex and precipitates

Answer 159

3 - competes with enzyme-labeled antigen for binding to a specific antibody

Question 160

Severe combined immunodeficiency (SCID) is an:

1. immunodeficiency with decreased B cells and neutrophils
2. immunodeficiency with lymphocytopenia and eosinophilia
3. immunodeficiency with decreased or dysfunctional T and B cells
4. immunodeficiency with decreased lymphocytes and decreased complement concentration

Answer 160

3 - immunodeficiency with decreased or dysfunctional T and B cells

Question 161

An example of immune injury due to the deposition of antigen-antibody complexes is:

1. acute glomerulonephritis
2. bee-sting allergy
3. contact dermitis
4. penicillin allergy

Answer 161

1 - acute glomerulonephritis

Question 162

The serologically detectable antibody produced in rheumatoid arthritis (RA) is primarily of the class:

1. IgA
2. IgE
3. IgG
4. IgM

Answer 162

4 - IgM

Question 163

In bone marrow transplantation, immuno-competent cells in the donor marrow may recognize antigens in the recipient and respond to those antigens. This phenomenon is an example of:

1. acute rejection
2. chronic rejection
3. graft versus host disease
4. hyperacute rejection

Answer 163

3 - graft versus host disease

Question 164

Multiple myeloma is a:

1. lymphoproliferative disease of T cells
2. cancer of plasma cells characterized by increased antibody concentration
3. lymphoproliferative disease resulting in a decrease in antibody production
4. cancer of monocytes characterized by increased kappa and lambda chain synthesis

Answer 164

2 - cancer of plasma cells characterized by increased antibody concentration

Question 165

Which one of the following describes a direct immunofluorescence assay:

1. conjugated reagent antigen reacts with antibodies to form antigen-antibody complexes
2. antigens react with unlabeled antibody forming antigen-antibody complexes that attach to labeled antibodies
3. a dye is attached to a molecule and it reacts with an immune complex to produce a color
4. conjugated reagent antibody reacts with antigen to form antigen-antibody complexes

Answer 165

4 - conjugated reagent antibody reacts with antigen to form antigen-antibody complexes

Question 166

In individuals allergic to pollen, hyposensitization protocols may be initiated. These individuals receive injections of:

1. allergen
2. pooled human antisera
3. monoclonal antibody directed against human T cells
4. monoclonal antibody directed against human B cells

Answer 166

1 - allergen

Question 167

After exposure to antigen, the first antibodies that can be detected belong to the class:

1. IgA
2. IgE
3. IgG
4. IgM

Answer 167

4 - IgM

Question 168

Corneal tissue may be transplanted successfully from one patient to another because:

1. the cornea is nonantigenic
2. corneal antigens do not activate T cells
3. anticorneal antibodies are easily surpressed
4. the cornea occupies a priviliged site not usually seen by the immune system

Answer 168

4 - the cornea occupies a priviliged site not usually seen by the immune system

Question 169

A kidney transplant from one identical twin to another is an example of a:

1. allograft
2. autograft
3. isograft
4. xenograft

Answer 169

3 - isograft

Question 170

In Bruton disease, measurement of serum immunoglobulins would show:

1. elevated levels of IgE
2. elevated levels of IgG
3. normal levels of IgG and IgM but reduced levels of IgA
4. the absence of all immunoglobulins

Answer 170

4 - the absence of all immunoglobulins

Question 171

Diagnosis of group A streptococci (Streptococcus pyogenes) infection is indicated by the presence of:

1. anti-protein A
2. anti-DNase B
3. anti-beta-toxin
4. C-reactive protein

Answer 171

2 - anti-DNase B

Question 172

A molecule found in human serum sometimes used as a tumor marker is:

1. alpha-Fetoprotein
2. HBsAg
3. biotin
4. CD1

Answer 172

1 - alpha-Fetoprotein

Question 173

Which cell is the principal source of interleukin 2:

1. B cell
2. T cell
3. monocyte
4. plasma cell

Answer 173

2 - T cell

Question 174

Diagnostic reagents useful for detecting antigen by the coagglutination reaction may be prepared by binding antibody to killed staphylococcal cells via the Fc receptor of staphylococcal protein A. The class of antibody bound by this protein is:

1. IgA
2. IgD
3. IgG
4. IgM

Answer 174

3 - IgG

Question 175

A major advantage of passive immunization compared to active immunization is that:

1. antibody is available more quickly
2. antibody persists for the life of the recipient
3. IgM is the predominant antibody class provided
4. oral administration can be used

Answer 175

1 - antibody is available more quickly

Question 176

The strength with which a multivalent antibody binds a multivalent antigen is termed the:

1. affinity
2. avidity
3. reactivity
4. valence

Answer 176

2 - avidity

Question 177

How does the secondary humoral immune response differ from the primary response:

1. the lag phase (the time between exposure to immunogen and production of antibody) is longer in the secondary immune response
2. IgM is the predominant antibody class produced in the secondary immune response
3. the antibody levels produced are higher in the secondary immune response
4. cytotoxic T lymphocytes play an important role in the secondary response

Answer 177

3 - the antibody levels produced are higher in the secondary immune response

Question 178

After activation of the complement system, leukocytes and macrophages are attracted to the site of complement activation by:

1. C1
2. C5a
3. C8
4. IgM

Answer 178

2 - C5a

Question 179

They type of immunity that follows the injection of an immunogen is termed:

1. artificial active
2. natural active
3. artificial passive
4. innate

Answer 179

1 - artificial active

Question 180

The type of immunity that follows the injection of antibodies synthesized by another individual or animal is termed:

1. artificial active
2. natural adaptive
3. artificial passive
4. natural passive

Answer 180

3 - artificial passive

Question 181

Innate immunity includes:

1. anamnestic response
2. antibody production
3. cytotoxic T cell activity
4. phagocytosis by polymorphonuclear cells

Answer 181

4 - phagocytosis by polymorphonuclear cells

Question 182

The antibody most frequently present in systemic lupus erythematosus is directed against:

1. surface antigens of bone marrow stem cells
2. surface antigens of renal cells
3. nuclear antigen
4. myelin

Answer 182

3 - nuclear antigen

Question 183

The rapid plasma reagin assay for syphilis does not need to be read microscopically because the antigen is:

1. cardiolipin
2. complexed with latex
3. complexed with charcoal
4. inactivated bacterial cells

Answer 183

3 - complexed with charcoal

Question 184

The Venereal Disease Research Laboratory (VDRL) test for syphilis is classified as a:

1. agglutination reaction
2. flocculation reaction
3. hemagglutination reaction
4. precipitation reaction

Answer 184

2 - flocculation reaction

Question 185

One cause of a false-positive VDRL test is:

1. Brucellosis
2. Treponema pallidum infection
3. Rocky Mountain spotted fever
4. Systemic lupus erythematosus

Answer 185

4 - Systemic lupus erythematosus

Question 186

The portion of an antigen that binds to an antibody or T cell receptor is called a:

1. allergin
2. avidin
3. epitope
4. valence

Answer 186

3 - epitope

Question 187

Identical antibodies produced from a single clone of plasma cells describes:

1. reagin
2. cold agglutinins
3. heterophile antibodies
4. monoclonal antibodies

Answer 187

4 - monoclonal antibodies

Question 188

IgM antibodies react well in complement fixation (CF) tests. Because of this, CF tests for antibodies should;

1. be positive early in the course of the disease
2. be useful in identifying antibodies responsible for a delayed hypersensitivity reaction
3. be useful in identifying antibodies responsible for anaphylactic reactions
4. detect transplacental antibodies

Answer 188

1 - be positive early in the course of the disease

Question 189

Which of the following serologic tests is commonly performed by an immunofluorescence method:

1. anti-HBs
2. antinuclear antibody (ANA)
3. antistreptolysin O (ASO)
4. C-reactive protein (CRP)

Answer 189

2 - antinuclear antibody (ANA)

Question 190

A woman wants to donate blood. Her physical exam reveals the following: weight - 110 lb, pulse - 73 bpm, blood pressure - 125/75 mmHg, hematocrit - 35%. Which of the following exlusions applies to the prospective donor:

1. pulse too high
2. weight too low
3. hematocrit too low
4. blood pressure too low

Answer 190

3 - hematocrit too low

Question 191

A potential donor has no exclusions, but she weighs only 95 pounds, What is the allowable amount of blood (including samples) that can be drawn:

1. 367 ml
2. 378 ml
3. 454 ml
4. 473 ml

Answer 191

3 - 454 ml

Question 192

Donors who have received blood or blood products within 12 months of when they desire to donate are deferred to protect the recipient because the:

1. blood could have transmitted hepatitis (HBV or HCV) or HIV
2. blood may have two cell populations
3. donor may not be able to tolerate the blood loss
4. donor red cell hemoglobin level may be too low

Answer 192

1 - blood could have transmitted hepatitis (HBV or HCV) or HIV

Question 193

Which of the following conditions would contraindicate autologous presurgical donation:

1. weight of 100 pounds
2. age of 14 years
3. hemoglin of 12g/dL
4. mild bacteremia

Answer 193

4 - mild bacteremia

Question 194

Which of the following donors would be deferred indefinitely:

1. History of syphilis
2. history of gonorrhea
3. accutane treatment
4. recipient of human growth hormone

Answer 194

4 - recipient of human growth hormone

Question 195

Which of the following viruses resides exclusively in leukocytes:

1. CMV
2. HIV
3. HBV
4. HCV

Answer 195

1 - CMV

Question 196

A donor indicates that he has taken two aspirin tablets per day for the last 36 hours. The unit of blood:

1. may not be used for pooled platelet concentrate preparation
2. should not be drawn until 36 hours after cessation of aspirin ingestion
3. may be used for pooled platelet concentrate preparation
4. may be used for red blood cells and fresh-frozen plasma production, but the platelets should be discarded

Answer 196

3 - may be used for pooled platelet concentrate preparation

Question 197

Which of the following best describes what must be done with a unit of blood drawn from a donor who is found to be at high risk of contracting acquired immune deficiency syndrome (AIDS):

1. hold unit in quarantine until donor diagnosis is clarified
2. use the blood for researach dealing with AIDS
3. properly dispose of unit by autoclaving or incineration
4. use the plasma and destroy the red blood cells

Answer 197

3 - properly dispose of unit by autoclaving or incineration

Question 198

Which of the following is least likely to transmit hepatitis:

1. cryoprecipitate
2. RBC
3. plasma protein fraction (PPF)
4. platelets

Answer 198

3 - plasma protein fraction (PPF)

Question 199

A pooled sera product from 16 donors has a repeatedly positive nucleic acid test (NAT) for HCV. The next action that should be taken is to:

1. permanently exclude all the donors in the pool
2. test each donor in the pool for HCV
3. label all the donors as HCV positive
4. confirm the positive using recombinant immunoblot assay (RIBA)

Answer 199

2 - test each donor in the pool for HCV

Question 200

Although cryoprecipitate has primarily been used for treatment of hypofibrinogenemia and hemophilia A, it contains other blood proteins useful in the treatment of coagulopathies. Which of the following is not found in cryoprecipitate:

1. fibronectin
2. factor XIII
3. factor VIII:vW
4. antithrombin III

Answer 200

4 - antithrombin III

Question 201

Even though it is properly collected and stored, which of the following will fresh-frozen plasma (FFP) not provide:

1. factor V
2. factor VIII
3. factor IX
4. platelets

Answer 201

4 - platelets

Question 202

Blood needs to be prepared for intrauterine transfusion of a fetus with severe HDN. The red blood cell unit selected is compatible with the mother’s serum and has been leuko-depleted. An additional step that must be taken before transfusion is to:

1. add pooled platelets and fresh-frozen plasma
2. check that the RBC group is consistent with the fathers’s
3. irradiate the RBCs before infusion
4. test the RBC unit with the neonate’s eluate

Answer 202

3 - irradiate the RBCs before infusion

Question 203

The addition of adenine in an anticoagulant-preservative formulation aids in:

1. maintaning ATP levels for red cell viability
2. maintaning platelet function in stored blood
3. reducing the plasma K+ levels during storage
4. maintaining 2,3-BPG levels for oxygen release to the tissues

Answer 203

1 - irradiate the RBCs before infusion

Question 204

The pilot tubes for donor unit #3276 break in the centrifuge. You should:

1. label the blood using the donor’s previous records
2. discard the unit because processing procedures cannot be performed
3. discard the red cells and salvage the plasma for fractionation
4. remove sufficient segments to complete donor processing procedures

Answer 204

4 - remove sufficient segments to complete donor processing procedures

Question 205

A satellite bag containing 250 mL of fresh plasma is selected for quality control of cryprecipitate production. Cryoprecipitate is prepared according to standard operating procedures. The final product has a total volume of 10 mL. The factor VIII assays are 1 IU/ml before and 9 IU/mL after preparation.

What is the percent yield of factor VIII in the final cryoprecipitate:

1. 11%
2. 25%
3. 36%
4. 80%

Answer 205

36%

Question 206

A satellite bag containing 250 mL of fresh plasma is selected for quality control of cryprecipitate production. Cryoprecipitate is prepared according to standard operating procedures. The final product has a total volume of 10 mL. The factor VIII assays are 1 IU/ml before and 9 IU/mL after preparation.

Does this product meet AABB Standards for cryoprecipitate production:

1. yes
2. no; the percent recovery is too low
3. no, the final factor VIII level is too low
4. data are insufficient to calculate

Answer 206

1 - yes

Question 207

A centrifuge used for platelet preparation has been returned after major repair. A unit of whole blood (450 mL; platelet count 200,000/uL) is selected for calibration of platelet production. The platelet-rich plasma (PRP) contains 250 mL with a platelet count of 300,000/uL. The final platelet concentrate prepared form the PRP contains 50mL with a platelet count of 900,000/uL.

What is the percent yield of platelets in the PRP form this unit:

1. 33%
2. 45%
3. 66%
4. 83%

Answer 207

4 - 83%

Question 208

A centrifuge used for platelet preparation has been returned after major repair. A unit of whole blood (450 mL; platelet count 200,000/uL) is selected for calibration of platelet production. The platelet-rich plasma (PRP) contains 250 mL with a platelet count of 300,000/uL. The final platelet concentrate prepared form the PRP contains 50mL with a platelet count of 900,000/uL.

What is the percent yield of platelets in the final product from the PRP:

1. 30%
2. 45%
3. 50%
4. 60%

Answer 208

4 - 60%

Question 209

A centrifuge used for platelet preparation has been returned after major repair. A unit of whole blood (450 mL; platelet count 200,000/uL) is selected for calibration of platelet production. The platelet-rich plasma (PRP) contains 250 mL with a platelet count of 300,000/uL. The final platelet concentrate prepared form the PRP contains 50mL with a platelet count of 900,000/uL.

Does this product meet AABB Standards for platelet concentrate production:

1. yes
2. no, the count on the final product is too low
3. no, the percentage recovery in the PRP is too low
4. data are insufficient to calculate

Answer 209

2 - no, the count on the final product is too low

Question 210

A centrifuge used for platelet preparation has been returned after major repair. A unit of whole blood (450 mL; platelet count 200,000/uL) is selected for calibration of platelet production. The platelet-rich plasma (PRP) contains 250 mL with a platelet count of 300,000/uL. The final platelet concentrate prepared form the PRP contains 50mL with a platelet count of 900,000/uL.

The final product was prepared with a PRP spin time of 2 minutes at 2500 rpm. To increase the percent platelet yield in the final product, one would:

1. increase the time and/or rpm for the first spin
2. increase the time and/or rpm for the second spin
3. decrease the time and/or rpm for the first spin
4. decrease the time and/or rpm for the second spin

Answer 210

2 - increase the time and/or rpm for the second spin

Question 211

When 2,3-BPG levels drop in stored blood, which of the following occurs as a result:

1. red blood cell K+ increases
2. red blood cell ability to release O2 decreases
3. plasma hemoglobin is stabilized
4. ATP synthesis increases

Answer 211

2 - red blood cell ability to release O2 decreases

Question 212

The last unit of autologous blood for an elective surgery patient should be collected no later than _______ hours before surgery:

1. 24
2. 36
3. 48
4. 72

Answer 212

4 - 72

Question 213

For which of the following patients would autologous donation not be advisable:

1. patients with an antibody against a high-incidence antigen
2. patients with uncompensated anemia
3. open heart surgery patients
4. patients with multiple antibodies

Answer 213

2 - patients with uncompensated anemia

Question 214

It is generally asymptomatic but has a very high carrier rate (70-80% have chronic infections). About 10% of the carriers develop cirrhosis or hepatocellular carcinoma. These statements are most typical of which of the following transfusion-transmitted infections:

1. HAV
2. HBV
3. HCV
4. HEV

Answer 214

3 - HCV

Question 215

Biochemical changes occur during the shelf life of stored blood. Which of the following is a result of this storage lesion:

1. increase in pH
2. increase in plasma K
3. increase in plasma Na
4. decrease in plasma hemoglobin

Answer 215

2 - increase in plasma K

Question 216

It has been determined that a patient has posttransfusion hepatitis and received blood from eight donors. There is nothing to indicate that these donors may have been likely to transmit hepatits. What action must be taken initially:

1. defer all donors indefinitely from further donations
2. repeat all hepatitis testing on a fresh sample from each donor
3. notify the donor center that cellected the blood
4. interview all implicated donors

Answer 216

3 - notify the donor center that cellected the blood

Question 217

The temperature range for maintaning red blood cells and whole blood during shipping is:

1. 0-4oC
2. 1-6oC
3. 1-10oC
4. 5-15oC

Answer 217

3 - 1-10oC

Question 218

Platelets play an important role in maintaining hemostasis. One unit of donor platelets derived from whole blood should yield ______ platelets:

1. 5.5 X 10⁶
2. 5 X 10⁸
3. 5.5 X 10¹⁰
4. 5 X 10¹⁰

Answer 218

3 - 5.5 X 10¹⁰

Question 219

The pH of four platelet concentrates is measured on the day of expiration. The pH and plasma volumes of the four units are as follows: pH 6.0, 45 mL ; pH 5.5, 38mL; pH 5.8, 40mL; pH 5.7, 41 mL. What corrective action is needed in product preparation to meet AABB standards for platelet production:

1. no corrective action is necessary
2. recalibrate pH meter
3. increase final plasma volume of platelet concentrates
4. decrease final plasma volume of platelet concentrates

Answer 219

3 - increase final plasma volume of platelet concentrates

Question 220

During preparation of platelet concentrate, the hermetic seal of the primary bag is broken­. The red blood cells:

1. must be discarded
2. may be labeled with a 21 day expiration date if collected in CPD
3. must be labeled with a 24 hour expiration date
4. may be glycerolized within 6 days and stored frozen

Answer 220

3 - must be labeled with a 24 hour expiration date

Question 221

The blood bank procedures manual must be:

1. revised annually
2. revised after publication of each new edition of AABB standards
3. reviewed prior to a scheduled inspection
4. reviewed annually by an authorized individual

Answer 221

4 - reviewed annually by an authorized individual

Question 222

Previous records of patients` ABO and Rh types must be immediately available for comparison with current test results:

1. for 6 months
2. 12 months
3. 10 years
4. indefinitely

Answer 222

2 - 12 months

Question 223

Which of the following weak D donor units should be labeled Rh-positif:

1. weak D due to transmissible genes
2. weak D as position effect
3. weak partial D
4. all of the above

Answer 223

4 - all of the above

Question 224

In order to meet the current AABB standards for leukocyte reduction to prevent HLA alloimmunization or CMV transmission, the donor unit must retain at least __________ of the original red cells and leukocytes must be reduced to less than ___________.

1. 85%, 5 X 10⁸
2. 80%, 5 X 10⁶
3. 75%, 5 X 10⁵
4. 70%, 5 X 10⁴

Answer 224

2 - 80%, 5 X 10⁶

Question 225

Which of the following tests is/are not performed during donor processing:

1. ABO and Rh grouping
2. HBs Ag
3. HIV-1-Ag
4. HBs Ab

Answer 225

4 - HBs Ab

Question 226

A 70 kg man has a platelet count of 15000/uL, and there are no complicating factors such as fever or HLA sensitization. If he is given a platelet pool of 6 units, what would you expect his posttransfusion count to be:

1. 21 000-27 000/ul
2. 25 000-35 000/ul
3. 45 000-75 000/ul
4. 75 000-125 000/ul

Answer 226

3 - 45 000-75 000/ul

Question 227

Which of the following tests on donor red blood cells must be repeated by the transfusing facility when the blood was collected and processed by a different facility:

1. confirmation of ABO group and Rh type of blood labeled D-negative
2. confirmation of ABO group and Rh type
3. weak D on D-negative
4. antibody screening

Answer 227

1 - confirmation of ABO group and Rh type of blood labeled D-negative

Question 228

What is the required storage temperature for red blood cells, liquid:

Answer 228

1-6oC

Question 229

What is the required storage temperature for red blood cells, frozen:

Answer 229

-65oC or colder

Question 230

What is the required storage temperature for fresh-frozen plasma:

Answer 230

-18oC

Question 231

What is the required storage temperature for cryoprecipitate:

Answer 231

-18oC

Question 232

What is the required storage temperature for platelet concentrate:

Answer 232

20-24oC

Question 233

What is the shelf life for red blood cells in CPDA-1:

Answer 233

35 days

Question 234

What is the shelf life for fresh-frozen plasma:

Answer 234

1 year

Question 235

What is the shelf life for cryoprecipitate:

Answer 235

1 year

Question 236

What is the shelf life for fresh-frozen plasma, thawed:

Answer 236

24 hours

Question 237

What is the shelf life for platelet concentrate in PL-732 (with agitation):

Answer 237

5 days

Question 238

What is the shelf life for blood for transfusing therapy using the anticoagulant/preservative CPD (citrate phosphate dextrose):

Answer 238

21 days

Question 239

What is the shelf life for blood for transfusing therapy using the anticoagulant/preservative CPDA-1 (citrate phosphate dextrose adenine):

Answer 239

35 days

Question 240

What is the shelf life for blood for transfusing therapy using the anticoagulant/preservative AS-1 (Adsol):

Answer 240

42 days

Question 241

What is the shelf life for blood for transfusing therapy using the anticoagulant/preservative EDTA:

Answer 241

Not an approved anticoagulant

Question 242

A test for the hydrolysis of esculin in the presence of bile is especially useful in identifying species of the genus:

1. Abiotrophia
2. Corynebacterium
3. Enterococcus
4. Staphylococcus

Answer 242

3 - Enterococcus

Question 243

The organism associated with a disease characterized by the presence of a pseudomembrane in the throat and the production of an exotoxin that is absorbed into the bloodstream with a lethal effect is:

1. Arcanobacterium haemolyticum
2. Staphylococcus aureus
3. Streptococcus pyogenes
4. Corynebacterium diphtheriae

Answer 243

4 - Corynebacterium diphtheriae

Question 244

Enterotoxin produced by Staphylococcus aureus is responsible for causing:

1. Carbuncles
2. Enterocolitis
3. Impetigo
4. Scalded skin syndrome

Answer 244

2 - Enterocolitis

Question 245

Abiotrophia, formerly knows as nutritionally variant streptococci, will not grow on routine blood or chocolate agars becasue they are deficient in:

1. hemin
2. pyridoxal
3. vitamine B12
4. thiophene-2-carboxylic hydrazide

Answer 245

2 - pyridoxal

Question 246

Exfoliatin produced by Staphylococcus aureus is responsible for causing:

1. Enterocolitis
2. toxic shock syndrome
3. scalded skin syndrome
4. Staphylococcal pneumonia

Answer 246

3 - scalded skin syndrome

Question 247

Streptococcus pyogenes can be presumptively identified using a:

1. PYR disk
2. ONPG disk
3. SPS disk
4. Optochin disk

Answer 247

1 - PYR disk

Question 248

A gram positive coccus that is catalase positive, nonmotile, lysostaphin resistant, and modified oxidase positive is best identified as a member of the genus:

1. Micrococcus
2. Lactococcus
3. Pediococcus
4. Staphylococcus

Answer 248

1 - Micrococcus

Question 249

Nocardia asteroidesi nfections in humans characteristically produce:

1. Carbuncles
2. draining cutaneous sinuses
3. septic shock
4. serous effusions

Answer 249

2 - draining cutaneous sinuses

Question 250

Erysipelothrix infections in humans characteristically produce:

1. pathology at the point of entrance of the organism
2. central nervous system pathology
3. pathology in the lower respiratory tract
4. the formation of abscesses in visceral organs

Answer 250

1 - pathology at the point of entrance of the organism

Question 251

In the Camp test, a single streak of a beta-hemolytic Streptococcus is placed perpendicular to a streak of beta-lysin-producing Staphylococcus aureus. After incubation, a zone of increased lysis in the shape of an arrowhead is noted; this indicates the presumptive identification of:

1. S. agalactiae
2. S. bovis
3. S. equinus
4. S. pyogenes

Answer 251

1 - S. agalactiae

Question 252

Staphylococcus saprophyticus, a recognized pathogen, is a cause of:

1. furuncles
2. impetigo
3. otitis media
4. urinary tract infections

Answer 252

4 - urinary tract infections

Question 253

The etiologic agent most commenly associated with septicemia and meningitis of newborns is:

1. Streptococcus agalactiae
2. Streptococcus bovis group
3. Streptococcus pneumoniae
4. Streptococcus pyogenes

Answer 253

1 - Streptococcus agalactiae

Question 254

Which of the following is the most commonly isolated species of Bacillus in opportunistic infections such as bacteremia, post-traumatic infections of the eye, and endocarditis:

1. B. circulans
2. B. cereus
3. B. licheniformis
4. B. subtilis

Answer 254

2 - B. cerous

Question 255

Loeffler’s serum medium is recommended for the cultivation of:

1. Abiotrophia sp.
2. Corynebacterium diphtheriae
3. Leuconostoc sp.
4. Streptococcus agalactiae

Answer 255

2 - Corynebacterium diphtheriae

Question 256

On Tinsdale agar, colonies of Corynebacterium diphtheriae are characterized by the observance of:

1. liquefaction of the agar surrounding the colonies on the medium
2. opalescent colonies with a white precipitate in the surrounding agar
3. black colonies on the culture medium surrounding by brown halos
4. pitting of the agar medium surrounding the colonies

Answer 256

3 - black colonies on the culture medium surrounding by brown halos

Question 257

Precipitates of diphtheria toxin and antitoxin formed in agar gels are in vitro means for detecting toxigenic strains of Corynebacterium diphtheriae. The name of this test procedure is the:

1. D-test
2. Elek test
3. Hodge test
4. Nagler test

Answer 257

2 - Elek test

Question 258

The etiologic agent of the disease erysipelas is:

1. Staphylococcus aureus
2. Streptobacillus moniliformis
3. Streptococcus agalactiae
4. Streptococcus pyogenes

Answer 258

4 - Streptococcus pyogenes

Question 259

Staphylococcus aureus, when present, could most likely be recovered from a stool sample if the primary plating medium included:

1. Bismuth sulfite
2. phenylethyl alcohol
3. thiosulfate citrate bile salts sucrose
4. xylose-lysine-desoxycholate

Answer 259

2 - phenylethyl alcohol

Question 260

A common member of the normal flora of the upper respiratory tract is:

1. Corynebacterium jeikeium
2. Lactobacillus
3. Staphylococcus epidermidis
4. Viridans streptococcus

Answer 260

4 - Viridans streptococcus

Question 261

Streptococci obtain all their energy from the fermentation of sugars to:

1. formic acid
2. lactic acid
3. succinic acid
4. valeric acid

Answer 261

2 - lactic acid

Question 262

Streptococci are unable to synthesize the enzyme:

1. catalase
2. kinase
3. hyaluronidase
4. lipase

Answer 262

3 - catalase

Question 263

The beta-hemolysis produced by group A Streptococcus seen on the surface of a sheep blood agar plate is primarily the result of streptolysin:

1. H
2. M
3. O
4. S

Answer 263

4 - S

Question 264

When an infection due to Streptomyces is suspected, isolates can be separated from most other bacteria by:

1. heat shocking the culture
2. incubating the culture at 25oC
3. incubating the culture at greater than 37oC
4. drying the specimen before inoculating the culture media

Answer 264

2 - incubating the culture at 25oC

Question 265

The production of H2S is one characteristic used to differentiate which of the aerobic gram-positive bacilli:

1. Corynebacterium
2. Erysipelothrix
3. Lactobacillus
4. Nocardia

Answer 265

2 - Erysipelothrix

Question 266

Growth in a 48 hour semisolid agar stab culture at room temperature reveals lateral filamentous growth away from the stab near the top of the medium. This observation is most characteristic of which organism:

1. Rhodococcus sp.
2. Corynebacterium urealyticum
3. Enterococcus faecalis
4. Listeria monocytogenes

Answer 266

4 - Listeria monocytogenes

Question 267

A former species of Corynebacterium pathogenic for swine, horses, and cattle is also known to cause disease in compromised hosts. This organism when grown on culture media produces pale pink colonies that help to presumptively identify it as:

1. Arcanobacterium hemolyticum
2. Actinomyces naeslundii
3. Gardnerella vaginalis
4. Rhodococcus equi

Answer 267

4 - Rhodococcus equi

Question 268

Which one of the following is not appropriate when describing Streptococcus pneumoniae:

1. bile-resistant
2. alpha-hemolytic
3. lancet-shaped, gram positive diplococcus
4. virulent strains are encapsulated

Answer 268

1 - bile-resistant

Question 269

Nocardia can be differentiated from Actinomyces based on:

1. Nocardia being an obligate anaerobe
2. the partial-acid fast staining reaction of Actinomyces
3. the production of sulfur granules in cases of nocardiosis
4. Nocardia being catalase positive

Answer 269

4 - Nocardia being catalase positive

Question 270

Enterococcus faecium is characteristically:

1. inhibited by the presence of bile in culture media
2. able to grow in the presence of high concentrations of salt
3. PYR negative
4. beta-hemolytic

Answer 270

2 - able to grow in the presence of high concentrations of salt

Question 271

A negative PYR test is demonstrated by:

1. Enterococcus faecalis
2. Enterococcus faecium
3. Streptococcus pyogenes
4. Viridans streptococci

Answer 271

4 - Viridans streptococci

Question 272

A gram stain of a sputum specimen from a patient with a suspected case of lobar pneumonia reveals many white blood cells and many gram positive cocci, which are primarily diplococci. Which of the following statements would be appropriate, given these findings:

1. a PYR test should be performed on the culture isolate
2. an Elek test should be performed on the culture isolate
3. an optochin test should be performed on the culture isolate
4. a hippurate hydrolysis test should be performed on the culture isolate

Answer 272

3 - an optochin test should be performed on the culture isolate

Question 273

A child presented in August at the pediactric clinic with a superficial skin infection of the neck. The large, itchy lesions were cultured, and the diagnosis of impetigo was made. One of the etiologic agents os this clinical condition is:

1. Erysipelothrix rhusiopathiae
2. Corynebacterium diphteriae
3. staphylococcus saprophyticus
4. Streptococcus pyogenes

Answer 273

4 - Streptococcus pyogenes

Question 274

An identifying characteristic of Staphylococcus aureus is:

1. DNase negative
2. coagulase negative
3. mannitol fermentation positive
4. growth inhibition in presence of increased salt

Answer 274

3 - mannitol fermentation positive

Question 275

Which of the following organisms is able to hydrolyze sodium hippurate to benzoic acid and glycine:

1. Streptococcus agalactiae
2. Streptococcus pneumoniae
3. Listeria monocytogenes
4. Enterococcus faecalis

Answer 275

1 - Streptococcus agalactiae

Question 276

Which of the following is not characteristic of Listeria monocytogenes:

1. CAMP test positive
2. catalase negative
3. esculin hydrolysis positive
4. motile

Answer 276

2 - catalase negative

Question 277

Which of the following is not associated with Staphylococcus aureus:

1. Endotoxin production
2. clumping factor production
3. deoxyribonuclease production
4. hemolysin production

Answer 277

1 - Endotoxin production

Question 278

Which of the following is a characteristic of staphylococci that would help in ther isolation from clinical specimens:

1. bile resistance
2. growth at 55oC
3. high salt tolerance
4. resistance to novobiocine

Answer 278

3 - high salt tolerance

Question 279

Which of the following species of Bacillus is nonmotile:

1. B. cereus
2. B. subtilis
3. B. anthracis
4. B. thuringiensis

Answer 279

3 - B. anthracis

Question 280

Which one of the following diseases involves erythrogenic toxin:

1. cutaneous anthrax
2. diptheria
3. impetigo
4. scarlet fever

Answer 280

4 - scarlet fever

Question 281

Cultures of the posterior pharynx are most commonly submitted to the clinical laboratory for the detection:

1. Corynebacterium diphteriae
2. Staphylococcus aureus
3. Streptococcus pneumoniae
4. Streptococcus pyogenes

Answer 281

4 - Streptococcus pyogenes

Question 282

Streptococcus sanguins, a viridans streptococcus, is most commonly associated with which of the follwoing clinical conditions:

1. otitis media
2. pharyngitis
3. relapsing fever
4. subacute bacterial endocarditis

Answer 282

4 - subacute bacterial endocarditis

Question 283

Rust-colored sputum in cases of lobar pneumonia is cahracteristic of which of the following possible etiologic agents:

1. Corynebacterium jeikeium
2. Staphylococcus aureus
3. Streptococcus pneumoniae
4. Streptococcus pyogenes

Answer 283

3 - Streptococcus pneumoniae

Question 284

A urine from a 23 year old female grew a catalse positive gram positive coccus, which would most likely be:

1. Staphylococcus saprophyticus
2. Enterococcus faecalis
3. Streptococcus bovis group
4. Streptococcus viridans

Answer 284

1 - Staphylococcus saprophyticus

Question 285

Cystine-tellurite blood agar plates are recommended for the isolation of:

1. Corynebacterium diphteriae
2. Streptococcus agalactiae
3. Streptococcus pyogenes
4. Group D streptococci

Answer 285

1 - Corynebacterium diphteriae

Question 286

The pulmonary form of anthrax is knows as:

1. valley fever
2. walking pneumonia
3. farmers’ lung
4. woolsorters disease

Answer 286

4 - woolsorters disease

Question 287

Pleomorphic gram positive bacilli in a gram stain best describes:

1. Bacillus antrhracis
2. Bacillus subtilis
3. Listeria monocytogenes
4. Corynebacterium pseudodiphtheriticum

Answer 287

4 - Corynebacterium pseudodiphtheriticum

Question 288

An aerobic gram positive rod known to cause bacteremia in hospitalized immuno compromised patients is:

1. Bacillus anthracis
2. Corynebacterium jeikeium
3. Corynebacterium ulcerans
4. Corynebacterium urealyticum

Answer 288

2 - Corynebacterium jeikeium

Question 289

A bone marrow transplant patient on immunosuppressive therapy developed a pulmonary abscess with symptoms of neurologic involvment. A brain abscess was detected by MRI, and aspirated material grew an aerobic, filamentous, branching gram positive organism, which stained weakly acid fast. The most liekly etiologic agent in this case would be:

1. Actinomyces israelii
2. Nocardia asteroides
3. Mycobacterium tuberculosis
4. Propionibacterium acnes

Answer 289

2 - Nocardia asteroides

Question 290

Which of the following is catalase negative:

1. Bacillus
2. Corynebacterium
3. Leuconostoc
4. Listeria

Answer 290

3 - Leuconostoc

Question 291

The retrovirus responsible for causing acruired immune deficiency syndrome is a member of the family:

1. Orthomyxoviridae
2. Paramyxoviridae
3. Retroviridae
4. Flaviviridae

Answer 291

3 - Retroviridae

Question 292

The appearance of Koplik spots in the oral mucosa of patients is characteristic of infection with what viral agent:

1. hepatitis
2. measles
3. rabies
4. smallpox

Answer 292

2 - measles

Question 293

Characteristics of this DNA hepatitis virus include infections spread by contaminated body fluids 50 to 180 day incubation period, and chronic infections:

1. HAV
2. HBV
3. HCV
4. HEV

Answer 293

2 - HBV

Question 294

Which of the following has been declared eradicated by the World Health Organization:

1. smallpox
2. human T cell lymphotropic virus
3. hepatitis G virus
4. eastern equine encephalitis

Answer 294

1 - smallpox

Question 295

Rotavirus is most common etiologic agent of:

1. acute nonbacterial encaphalitis in children
2. acute nonbacterial gastroenteritis in infants and young children
3. chronic nonbacterial pharyngitis in children and young adults
4. chronic nonbacterial retinitis in children

Answer 295

2 - acute nonbacterial gastroenteritis in infants and young children

Question 296

Kaposi sarcoma is associated with infection by:

1. adenovirus
2. cytomegalovirus
3. hepatitis E virus
4. human herpes virus 8

Answer 296

4 - human herpes virus 8

Question 297

The molecular receptor of the virus causing acquired immune deficiency syndrome is:

1. CD4
2. CD8
3. Fc receptor
4. complement receptor

Answer 297

1 - CD4

Question 298

The type of cell culture that best suppports the growth of cytomegalovirus is:

1. HeLa cells
2. HEp-2 cells
3. human fibroblast cells
4. primary monkey kidney (PMK) cells

Answer 298

3 - human fibroblast cells

Question 299

Which of the following viruses is predominently associated with respiratory disease and epidemics of keratoconjunctivitis:

1. adenovirus
2. molluscum contagiosum virus
3. norwalk virus
4. rotavirus

Answer 299

1 - adenovirus

Question 300

A 25 year old patient presented with multiple vesicles around the mouth. Material from the lesions was obtained by needle aspiration and inoculated to MRC-5 cells. After 1 day, the cytopathic effect included foci of ballooned and lysed cells. These observations suggest infection with:

1. adenovirus
2. cytomegalovirus
3. epstein-barr virus
4. herpes simplex virus

Answer 300

4 - herpes simplex virus

Question 301

The Sabin polio vaccine uses which of the following:

1. formalin-inactivated virus
2. attenuated viruses
3. recombinant viral antigens
4. DNA

Answer 301

2 - attenuated viruses

Question 302

Which of the following is caused by a herpes virus:

1. cold sores
2. hemorrhagic fever
3. polio
4. rabies

Answer 302

1 - cold sores

Question 303

Which of the following is not a general characteristic of a virus:

1. obligate intracellular parasite
2. does not produce ATP
3. genome is surrounded by a protein coat
4. can self-replicated in the appropriate host cell

Answer 303

4 - can self-replicated in the appropriate host cell

Question 304

The viral disease shingles, which causes extreme tenderness along the dorsal nerve roots and a vesicular erpution, has the same etiologic agent as:

1. rubeola
2. vaccinia
3. varicella
4. variola

Answer 304

3 - varicella

Question 305

The etiologic agents of many common colds are RNA viruses that grow better at 33oC than at 37oC. These viruses are:

1. adenovirus
2. orthomyxoviruses
3. paramyxoviruses
4. rhinoviruses

Answer 305

4 - rhinoviruses

Question 306

Influenza A virus undergoes recombination events that produce new strains; this is referred to as:

1. antigenic drift
2. antigenic shift
3. reactivation
4. viral latency

Answer 306

2 - antigenic shift

Question 307

Negri bodies may be found in brain tissue of humans or animals infected with:

1. adenovirus
2. filovirus
3. measles virus
4. rabies virus

Answer 307

4 - rabies virus

Question 308

Molluscum contagiosum virus is a member of the:

1. Adenoviruses
2. Herpesviruses
3. Papovaviruses
4. pox viruses

Answer 308

4 - pox viruses

Question 309

A clinical specimen is received in viral transport medium for viral isolation. The specimen cannot be processed for 72 hours. At what temperature should it be stored:

1. -80oC
2. -20oC
3. 4oc
4. 22oC

Answer 309

1 - -80oC

Question 310

Arboviruses:

1. only infect humans
2. often cause hepatitis
3. typically infect lymphocytes
4. are transmitted by arthropods

Answer 310

4 - are transmitted by arthropods

Question 311

Mumps is characterized by an infection of the:

1. central nervous system
2. parotid glands
3. pancreas
4. thymus

Answer 311

2 - parotid glands

Question 312

Which of the following hepatitis viruses is typically transmitted by the fecal-oral pathway:

1. HAV
2. HBV
3. HCV
4. HGV

Answer 312

1 - HAV

Question 313

Enteroviruses are most often associated with:

1. acute nonspecific febrile syndrome
2. bronchitis and pneumonia
3. lower respiratory tract infections
4. upper respiratory tract infections

Answer 313

1 - acute nonspecific febrile syndrome

Question 314

The core window refers to the time:

1. during hepatitis B virus infection when anti-HBc IgM is the only serologic marker
2. during hepatitis B virus infection when HBc is the only serologic marker
3. during hepatitis A virus infection when HAc is the only serologic marker
4. during hepatitis C virus infection when the virus is latent

Answer 314

1 - during hepatitis B virus infection when anti-HBc IgM is the only serologic marker

Question 315

Human herpesviruses 6 and 7 are associated with a childhood disease called:

1. chickenpox
2. measles
3. roseola
4. zoster

Answer 315

3 - roseola

Question 316

A baby was admitted to the hospital in February for dehydration due to severe diarrhea. Cultures for bacterial pathogens revealed normal fecal flora at 24 hours. Which of the following additional tests would be most appropriate given the case history:

1. heterophile antibody test
2. rotavirus antigen assay of stool specimen
3. McCoy cell inoculation for cytomegalovirus
4. urine microscopic analysis for presence of CMV cellular inclusion bodies

Answer 316

2 - rotavirus antigen assay of stool specimen

Question 317

Rhabdovirus is most noted for causing infections of the:

1. central nervous system
2. gastrointestinal tract
3. lower respiratory tract
4. upper respiratory tract

Answer 317

1. central nervous system

Question 318

Jaundice is a common clinical symptom of which of the following viral disease:

1. hepatitis A
2. infectious mononucleosis
3. rabies
4. varicella

Answer 318

1 - Hepatitis A

Question 319

An 18 year old male presents to his family physician complaining of sore throat and fatigue. The patient is found to have a fever and swollen cervical lymph nodes. A complete blood count and differential reveal lymphocytosis and many reactive lymphocytes. The physician should suspect an infection caused by:

1. adenoviruses
2. epstein-barr virus
3. parainfluenza virus
4. varicella-zoster virus

Answer 319

2 - epstein-barr virus

Question 320

The poliovirus, an RNA virus is a:

1. adenovirus
2. coxsackie virus
3. enterovirus
4. rhinovirus

Answer 320

3 - enterovirus

Question 321

The virus that causes hepatitis B is characterized as a:

1. defective DNA virus requiring delta virus to complete its replication cycle
2. DNA virus utilizing reverse transcriptase
3. nonenveloped DNA virus
4. single stranded RNA virus

Answer 321

2 - DNA virus utilizing reverse transcriptase

Question 322

Hepatitis C virus infections:

1. are commonly diagnosed during the acute stage
2. are uncommon in the US
3. are most often acquired by contact with blood
4. seldom results in chronic infection

Answer 322

3 - are most often acquired by contact with blood

Question 323

Characteristic cytopathic effect associated with respiratory syncytial virus is:

1. giant multinucleated cells
2. basophilic intranuclear inclusions
3. eosinophilic cytoplasmic inclusions
4. shrunken cells with multilobed nuclei

Answer 323

1 - giant multinucleated cells

Question 324

The virus associated with warts is:

1. flavivirus
2. Morbillivirus
3. Mumps virus
4. Papillomavirus

Answer 324

4 - Papillomavirus

Question 325

RNA dependant DNA polymerase is also called:

1. gyrase
2. neuraminidase
3. reverse transcriptase
4. transaminase

Answer 325

3 - reverse transcriptase

Question 326

Coxsackie viruses are associated with :

1. gastrointestinal disease
2. hepatitis
3. myocarditis
4. the common cold

Answer 326

3 - myocarditis

Question 327

The tubular cells of the human kidney shed which of the following viruses for prolonged periods:

1. Adenovirus
2. Cytomegalovirus
3. Epstein-barr virus
4. Rubella virus

Answer 327

2 - Cytomegalovirus

Question 328

The togavirus known to produce fetal defects is:

1. Influenza
2. Rotavirus
3. Rubella
4. Varicella

Answer 328

3 - Rubella

Question 329

An 8 week old infant was admitted to the hospital with symptoms of low birth weight, jaundice, and neurologic defects. Intranuclear inclusions were found in epithelial cells from the urine. The most likely diagnosis in this case would be infection by:

1. Cytomegalovirus
2. Epstein-Barr virus
3. Herpes simplex virus
4. Rubella virus

Answer 329

1 - Cytomegalovirus

Question 330

The most common cause of cervical cancer is:

1. Cytomegalovirus
2. Enterovirus
3. Molluscum contagiosum
4. Papillomavirus

Answer 330

4 - Papillomavirus

Question 331

Select the statement that is correct concerning the influenza A viruses:

1. humans are the only animal hosts for influenza A viruses
2. pandemics are characteristically produced by influenza A
3. the incidence of infection peaks in the summer months
4. they are DNA viruses

Answer 331

2 - pandemics are characteristically produced by influenza A

Question 332

An example of a virus associated with latent infection is:

1. Influenza
2. Rotavirus
3. Rubella
4. Varicella-zoster

Answer 332

4 - Varicella-zoster

Question 333

The use of cell cultures has enabled virologists to isolate and identify many clinically important viruses. However, because some viruses cannot be grown in cell cultures, these agents are best diagnosed by serologic testing. Such an agent is:

1. Cytomegalovirus
2. Hepatitis C virus
3. Herpes simplex virus 2
4. respiratory syncytial virus

Answer 333

2 - Hepatitis C virus

Question 334

Which of the following is associated with the rubella virus:

1. it is a DNA virus
2. it is a member of the same taxonomic family as measles virus
3. it is known to produce defects in fetuses during the early stages of pregnancy
4. it is transmitted by an arthropod vector

Answer 334

3 - it is known to produce defects in fetuses during the early stages of pregnancy

Question 335

Which of the following is not a step involved in virus replication:

1. attachment
2. mitosis
3. penetration
4. release

Answer 335

2 - mitosis

Question 336

Which of the following opportunistic diseases is not closely associated with acquired immune deficiency syndrome:

1. Cryptococcosis
2. Cryptosporidiosis
3. Malaria
4. Mycobacteriosis

Answer 336

3 - Malaria

Question 337

Although there have been no natural cases of this serious disease in about 30 years, which of the following is considered a potential bioterrorism disease:

1. Dengue
2. Ebola hemorrhagic fever
3. Shingles
4. Smallpox

Answer 337

4 - Smallpox

Question 338

Poliovirus is a member of the family:

1. Flaviviridae
2. Paramyxoviridae
3. Picornaviridae
4. Reoviridae

Answer 338

3 - Picornaviridae

Question 339

Which of the following has not been successfully used to detect viruses in clinical specimens:

1. cytopathic effect
2. enzyme-linked immunosorben assay
3. growth on selective agar media
4. immunofluorescence

Answer 339

3 - growth on selective agar media

Question 340

Which of the following diseases is not associated with herpes simplex virus:

1. cold sores
2. Encephalitis
3. genital herpes
4. thrush

Answer 340

4 - thrush

Question 341

If 20% of the nucoletides in an organism are adenine, predict the percentage of nucleotides that are guanine:

1. 20%
2. 30%
3. 40%
4. 60%

Answer 341

2 - 30%

Question 342

Which of the following is not required for DNA replication by PCR:

1. oligonucleotide primers
2. DNA polymerase
3. DNA ligase
4. deoxynucloetides

Answer 342

3 - DNA ligase

Question 343

In naming restriction endonucleases, the first letter of the name comes from the:

1. bacterial genus
2. bacterial species
3. scientist who discovered it
4. geographic location of its discovery

Answer 343

1 - bacterial genus

Question 344

A restriction enzyme recogniaes the sequence 5’ CT ^ ATAG 3’, and cuts as indicated. Predict the ends that would result on the complementary DNA strand:

1. 3’ G 5’ 3’ ATATC 5’
2. 3’ GA 5’ 3’ TATC 5’
3. 3’ GATA 5’ 3’ TC 5’
4. 3’ GATAT 5’ 3’ C 5’

Answer 344

3 - 3’ GATA 5’ 3’ TC 5’

Question 345

In the isolation of RNA, diethylpyrocarbonate (DEPC) is used to:

1. inhibit RNase
2. lyse the cells
3. precipitate the DNA
4. remove buffer salts

Answer 345

1 - inhibit RNase

Question 346

Purification resins used to isolate DNA take advantage of the fact that DNA is:

1. double stranded
2. negatively charged
3. higher in concentration than RNA
4. higher molecular weight than RNA

Answer 346

2 - negatively charged

Question 347

After performance of DNA electrophoresis, the isolated bands in the kilobase size range appear too close together. Which of the following can be done with the next run to improve the appearance/seperation of the bands in the samples:

1. increase the percent agarose concentration of the matrix
2. increase the running time of the electrophoresis assay
3. increase the sample volume applied to the gel
4. decrease the sample volume applied to the gel

Answer 347

2 - increase the running time of the electrophoresis assay

Question 348

Which of the following is commonly used as a label in molecular tests:

1. biotin
2. DNase
3. RNase
4. I¹²⁵

Answer 348

1 - biotin

Question 349

Which of the folowing is not an example of target amplification:

1. reverse transcription-PCR
2. transcirption mediated amplification
3. branched chain DNA amplification
4. polymerase chain reaction

Answer 349

3 - branched chain DNA amplification

Question 350

In forensic testing, DNA fingerprinting can identify individuals with high accuracy because:

1. human genes are highly conserved
2. only a small amount of sample is needed
3. human gene loci are polymorphic
4. DNA is stable and not easily contaminated

Answer 350

3 - human gene loci are polymorphic

Question 351

The technique that makes ssDNA from an RNA template is called:

1. strand displacement amplification
2. polymerase chain reaction
3. ligase chain reaction
4. reverse transcription

Answer 351

4 - reverse transcription

Question 352

Which of the following is characteristic of DNA chips:

1. allow detection and discrimination of multiple genetic sequences at the same time
2. thousands of oligonucleotide probes are labeled and placed on glass or silicon surfaces
3. unlabeled target sequences within the patient sample are detected by hybridization to labeled probes
4. all of the above

Answer 352

1 - allow detection and discrimination of multiple genetic sequences at the same time

Question 353

The most useful feature of the molecules streptavidin and biotin is that they bind:

1. specifically to nucleic acids
2. only in neutral pH conditions
3. to each other with very high affinity
4. directly to DNA immobilized on nitrocellulose

Answer 353

3 - to each other with very high affinity

Question 354

What is the theoretic estimation of the number of DNA target sequences present following 15 cycles of PCR:

1. 30
2. 2¹⁰
3. 2¹⁵
4. 2²⁰

Answer 354

3 - 2¹⁵

Question 355

Star activity for a restriction enzyme refers to:

1. an ability to cleave DNA at sequences different from their defined recognition sites
2. the enzyme’s specificity for sites of methylation within the nucleotide sequence
3. the temperature and pH conditions at which the enzyme will function optimally
4. the percent increased accuracy of the enzyme when placed in ideal conditions of pH

Answer 355

1 - an ability to cleave DNA at sequences different from their defined recognition sites

Question 356

What enzyme recognizes and cuts overlapping DNA sequences formed between mutant or normal probes and target sequences within samples:

1. restriction endonuclease
2. DNA ligase
3. cleavase
4. RNase H

Answer 356

3 - cleavase

Question 357

If a DNA probe is added to nitrocellulose after the transfer step but before the blocking step, which of the following will occur:

1. the probe will nonspecifically bind to its DNA target
2. unoccupied spaces on the nitrocellulose will bind the probe
3. the DNA target on the nitrocellulose will be unable to bind the probe
4. bound probe will be washed away in the next wash step

Answer 357

2 - unoccupied spaces on the nitrocellulose will bind the probe

Question 358

Which of the following items is not used in the preperation of a dNA probe for southern blotting using random hexamer primers:

1. template DNA
2. three unlabeled deoxynucleotides
3. dideoxynucleotides, with one of them labeled
4. DNA polymerase

Answer 358

3 - dideoxynucleotides, with one of them labeled

Question 359

Which of the following is considered a high stringency condition for DNA probe protocols:

1. using wash buffer with highly acidic pH
2. washing the matrix with high salt buffer
3. radiolabeling the probe with ³⁵S rather than ³²P
4. washing the transfer membrane at high temperature

Answer 359

4 - washing the transfer membrane at high temperature

Question 360

When compared to southern blot hybridization testing, PCR

1. is less sensitive to DNA degradation than southern blot
2. includes transfer of DNA onto a nylon membrane
3. requires no specialized equipment
4. is more labor intensive

Answer 360

1 - is less sensitive to DNA degradation than southern blot

Question 361

Which of the following specimen types is not used routinely as source material for molecular genetic tests:

1. whole blood
2. buccal scrapings
3. aminocytes
4. rectal swabs

Answer 361

4 - rectal swabs

Question 362

In the presence of salt, DNA is precipitated from solution by:

1. 10 mM Tris, 1 mM EDTA
2. 0.1% sodium dodecyl sulfate
3. alkaline buffers, such as 0.2 N NaOH
4. alcohols such as 95% ethanol or isopropanol

Answer 362

4 - alcohols such as 95% ethanol or isopropanol

Question 363

TaqMan probes used to increase specificity of real time PCR assays generate a fluorescent signal:

1. at the beginning of each cycle during the denaturation step
2. when the probes bind to the template
3. when the probe is digested by 5’ → 3’ exonuclease activity during extension of primers
4. when the reporter fluorophor on the probe is seperated from the quencher molecule by a restriction enzyme

Answer 363

3 - when the probe is digested by 5’ → 3’ exonuclease activity during extension of primers

Question 364

For the purpose of diagnosing genetic diseases, what component of whole blood is used for the extraction of DNA:

1. leukocytes
2. plasma
3. platelets
4. red blood cells

Answer 364

1 - leukocytes

Question 365

Which of the following statements best describes characteristics of RNase:

1. it degrades mRNA but nor rRNA
2. it is found in large concentrations on hands
3. its activity can be eliminated by autoclaving
4. its activity occurs in a limited temperature range between 25 and 65oc

Answer 365

2 - it is found in large concentrations on hands

Question 366

Which of the following is the least likely inhibitor of PCR:

1. heme
2. sodium heparin
3. DEPC
4. EDTA

Answer 366

4 - EDTA

Question 367

Frequently, DNA probes are used to detect target sequences in northern or southern blots. Hybridization occurs between DNA probe and RNA or DNA on the blot, respectively. To ensure that only exactly matched complementary sequences have bound together, the blot is washed under stringent conditions. Stringency of the wash steps to remove unbound and mismatched probe can be increased by:

1. high temperature, high NaCl concentration, and high detergent solution
2. high tempearture, low NaCl concentration, and high detergent solution
3. high temperature, high NaCl concentration, and low detergent solution
4. low temperature, high NaCl concentration, and high detergent solution

Answer 367

2 - high tempearture, low NaCl concentration, and high detergent solution

Question 368

In RNA, which nucleotide base replaces thymine of DNA:

1. adenine
2. cytosine
3. guanine
4. uracil

Answer 368

4 - uracil

Question 369

The component parts of a dNTP include a purine or pyrimidine base, a:

1. ribose sugar, and one phosphate group
2. deoxyribose sugar, and three phosphate groups
3. ribose sugar, and two phosphate groups
4. deoxyribose sugar, and two phosphate groups

Answer 369

2 - deoxyribose sugar, and three phosphate groups

Question 370

When comparing two dsDNA sequences of equal length, the strand that has a higher:

1. G + C content has a higher melting temperature
2. A + T content has a higher melting temperature
3. A + T content has more purines than pyrimidines along its length
4. G + C content has more purines than pyrmidines along its length

Answer 370

1 - G + C content has a higher melting temperature

Question 371

Molecular typing of bacterial strains is based on restriction fragment length polymorphisms produced by digesting bacterial chromosomal DNA with restriction endonucleases. Which of the following techniques is used to seperate the large DNA fragments generated:

1. ribotyping
2. DNA sequencing
3. pulsed field gel electrophoresis
4. reverse transcription polymerase chain reaction

Answer 371

3 - pulsed field gel electrophoresis

Question 372

Which of the following amplification methods does not employ isothermal conditions:

1. nucleic acid sequence based amplification
2. polymerase chain reaction
3. strand displacement amplification
4. transcription mediated amplification

Answer 372

2 - polymerase chain reaction

Question 373

The coding region of a human gene is called:

1. exon
2. intron
3. SNP
4. VNTR

Answer 373

1 - exon

Question 374

The central dogma is that DNA is used to make RNA, which is then used to make protein. In this scheme the two processes that are involved are termed:

1. replication and transcription
2. synthesis and encryption
3. transcription and translation
4. initiation and elongation

Answer 374

1 - replication and transcription

Question 375

How many chromosomes are contained in a normal human somatic cell:

1. 22
2. 23
3. 44
4. 46

Answer 375

4 - 46

Question 376

An ordered sequence of events makes up the cell cycle. Which of the following describes the correct sequence of events starting at G1:

1. G1, G2, S, M
2. G1, S, G2, M
3. G1, M, G2, S
4. G1, S, M, G2

Answer 376

2 - G1, S, G2, M

Question 377

Purified DNA remains stable indefinitely when stored as:

1. small aliquots at 4oC
2. large aliquots at 25oC
3. small aliquots at -70oC
4. large aliquots at -20oC

Answer 377

3 - small aliquots at -70oC

Question 378

An advantage of amplification technologies for clinical laboratories is that:

1. they require inexpensive test reagents
2. they lend themselves to automated methods
3. each target molecule sought requires a unique set of primers
4. contamination is not a concern when performing these assays

Answer 378

2 - they lend themselves to automated methods

Question 379

The assay methods that detects the expression of a gene rather than the mere presence or structure of a gene is termed:

1. RT-PCR
2. TMA
3. multiplex PCR
4. ribotyping

Answer 379

1 - RT-PCR

Question 380

Which of the following assays cannot be accomplished using PCR methods employing only Taq polymerase:

1. diagnosis of Chlamydia trachomatis and Neisseria gonorrhoeae infection
2. detection of single base pair gene mutations, such as in cystic fibrosis
3. detection of HLA-A, B and DR genotypes
4. determination of viral load for HCV

Answer 380

4 - determination of viral load for HCV

Question 381

One method to prevent false positive PCR results includes the use of dUTP in the reaction mix, resulting in amplicons containing U in place of T. The enzyme used to decrease contamination is:

1. Uracil-N-glycosylase
2. Taq polymerase
3. S1 nuclease
4. DNase

Answer 381

1 - Uracil-N-glycosylase

Question 382

The translocation resulting in the Philadelphia chromosome is detected by:

1. southern blot analysis only
2. cytogenic analysis only
3. PCR, southern blot, and cytogenetic analysis
4. RT-PCR, southern blot, and cytogenetic analysis

Answer 382

4 - RT-PCR, southern blot, and cytogenetic analysis