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55 Cards in this Set
- Front
- Back
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1. Who among the following pioneers of microbiology is credited with the discovery of microorganisms using high-qua1ity magnifying lenses?
A. Hooke B. Antony van Leeuwenhoek C. Robert Koch D. Louis Pasteur |
.B. Antony van Leeuwenhoek
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2. Which of the following statements is WRONG regarding Chlamydiae?
A. Require living cells for reproduction B. Use host cells to produce ATP and reproduce as obligate parasites C. The major diseases caused are trachoma and inclusion conjunctivitis D. Reticulate body is the infectious form while elementary body is the reproductive form |
.D. Reticulate body is the infectious form while elementary body is the reproductive form
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3. A capsule comprised of polypeptide of glutamic acid is found in:
A. Bacillus anthracis B. Streptococcus pneumoniae C. Hemophilus influenzae D. Streptococcus pyogenes E. Streptococus agalactiae |
.C. Decline phase
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4. In which phase of a typical bacterial growth curve, the cell death rate exceeds the multiplication rate
A. Lag phase B. Log phase C. Decline phase D. Stationary phase |
E. Adherence to surfaces and exchange of genetic information
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5. Bacterial pili present on the outer cell surface are used for:
A. Cellular motility B. Adherence to surfaces C. Cell wall synthesis D. Exchange of genetic information E. Adherence to surfaces and exchange of genetic information |
E. Adherence to surfaces and exchange of genetic information
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6. The purpose of heat-fixation of bacterial smear is to:
A. Cause the bacteria to adhere to the slide B. More quickly dry the specimen C. Cause the bacteria to shrink and then adhere to the slide D. Cause the bacteria to adhere to the slide, kill them make them more readily stainable |
..D. Cause the bacteria to adhere to the slide, kill them make them more readily stainable
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7. The sequence of using reagents for Gram staining of bacteria is:
A. Iodine (Grams iodine), Safranin, Decolorizing agent, Crystal violet B. Crystal violet, Iodine (Grams iodine), Safranin, Decolorizing agent C. Crystal violet, Iodine (Grams iodine), Decolorizing agent, Safranin D. Safranin, Iodine (Grams iodine), Decolorizing agent, Crystal violet |
.Crystal violet, Iodine (Grams iodine), Decolorizing agent, Safranin
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8. Particles made up of nucleic acids, proteins, and in some cases lipids that can reproduce only by infecting living cells are known as:
A. Bacteria B. Fungi C. Viruses D. Capsids |
.C. Viruses
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9. Which of the following statements is WRONG for bacterial plasmids?
A. They are extra-chromosomal genetic elements B. They are comprised of circular piece of DNA C. May become integrated into bacterial DNA. D. They can be transferred between bacteria E. They do not carry genes for antibiotic resistance |
.E. They do not carry genes for antibiotic resistance
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10. Gram positive, anaerobic, filamentous non-acid-fast bacteria with filaments breaking into rods and cocci belong to the genus:
A. Corynebacterium B. Mycobacterium C. Actinomyces D. Nocardia E. Bacillus |
.C. Actinomyces
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11. Which of the following bacteria is employed for quality control of sterilization by autoclaving?
A. Bacillus subtilis B. Bacillus cereus C. Bacillus stearothermophilus D. Clostridium perfringens |
.C. Bacillus stearothermophilus
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12. An example of a microaerophilic bacterium is:
A. Vibrio cholerae B. Escherichia coli C. Mycobacterium tuberculosis D. Haemophilus influenzae E. Campylobacter jejuni |
.E. Campylobacter jejuni
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13. Two bacterial populations are involved in conjugation. The donor bacterium can be differentiated form the recipient bacterium by the presence of:
A. F plasmid B. Flagella C. Resistance transfer factor D. All of the above E. None of the above |
.A. F plasmid
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14. In which phase of a typical bacterial growth curve, the cell death rate exceeds the multiplication rate
A. Lag phase B. Log phase C. Decline phase D. Stationary phase |
.C. Decline phase
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15. During an outbreak of gastrointestinal disease due to a strain of Escherichia coli sensitive to ampicillin, tetracycline, and chloramphenicol, a stool sample from one patient yields E. coli with the same serotype resistant to these three antibiotics. Which of the following mechanisms could be responsible for the development of multiple antibiotic resistance in this strain?
A. Conjugation B. Transformation C. Transduction D. Transposition E. Spontaneous mutation |
.A. Conjugation
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16. Which situation below describes an example of innate immunity?
A. Antibody production by plasma cells B. Antigen removal by cilia in the respiratory tract C. Complement activation by antibody bound to the surface of a bacterium. D. Memory response to influenza virus. |
.B. Antigen removal by cilia in the respiratory tract
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17. A pulmonologist performs bronchoscopy in the procedure room of the out-patient department. To make the instrument safe for use in the next patient waiting outside, the most appropriate method to disinfect the bronchoscope is by:
A. 70% ethanol for 5 min B. 2% glutaraldehyde for 20 min C. 2% formaldehyde for 20 min. D. 1% sodium hypochlorite for 15 min |
.B. 2% glutaraldehyde for 20 min
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18. A culture of pus from skin lesions in a patient yields numerous β-hemolytic colonies on blood agar plate. Gram stained smear from a representative colony shows Gram positive cocci, negative for catalase, and positive for sensitivity to bacitracin. Which of the following organisms has MOST likely been recovered on the blood agar plate?
A. Streptococcus pyogenes B. Staphylococcus aureus C. Staphylococcus epidermidis D. Streptococcus pneumoniae |
.A. Streptococcus pyogenes
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19. The greatest amount of chromosomal DNA can be transferred by:
A. Hfr x F conjugation B. F’ x F- mating C. Plasmid transfer D. Transportation of transposable elements E. Specialized transduction |
.A. Hfr x F conjugation
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19. Antigen binding site on the antibody is located in:
A. Constant region B. Hinge region C. Hypervariable region D. All of the above |
.C. Hypervariable region
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20. Culture of throat swab from the bronchial aspirate of a 30-year-old female with pharyngitis yields a Gram positive alpha-hemolytic, catalase negative coccus, which is sensitive to optochin. The organism is most likely to be:
A. Streptococcus pyogenes B. Viridans streptococci C. Staphylococcus epidermidis D. Staphylococcus aureus E. Streptococcus pneumoniae |
.E. Streptococcus pneumoniae
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21. Active immunity is NOT acquired by:
A. Infection B. Vaccination C. Sub-clinical infection D. Immunoglobulin administration |
.D. Immunoglobulin administration
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22. Which is true for Clonal selection in Immunity?
A. B cells (and T cells) that encounter stimulating antigen will proliferate into a large group of cells B. Lymphocyte specificity is preprogrammed, existing in the genetic makeup before an antigen has ever entered the system. C. Each genetically different type of lymphocyte expresses a single specificity. D. First introduction of each type of antigen into the immune system selects a genetically distinct lymphocyte and causes it to expand into a clone of cells that can react to that antigen. E. All of the above |
.A. B cells (and T cells) that encounter stimulating antigen will proliferate into a large group of cells
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23. Which is WRONG statement regarding IgA?
A. Exists as dimer in serum and monomer in mucus secretions B. Constitutes 19% of the immunoglobulin in serum C. Is found in serum, colostrum, respiratory and intestinal mucous membranes, saliva, and tears. D. Is an important component of mucosal immunity |
.A. Exists as dimer in serum and monomer in mucus secretions
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24. Which is NOT a property of IgM?
A. Pentameter B. First antibody produced during an infection C. Constitutes 5-10% of serum antibodies D. Crosses the placenta E. Its monomeric form is present on B cell surface |
.D. Crosses the placenta
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25. Which is WRONG statement regarding T cells?
A. Mature in the thymus. B. Are involved in helping B cells become antibody-producing plasma cells. C. Do not have specific receptors (T-cell receptors) on their surface for antigen recognition. D. Are involved in cell-mediated immunity. E. Participate in suppression of the immune response 25. Which is WRONG statement regarding T cells? A. Mature in the thymus. B. Are involved in helping B cells become antibody-producing plasma cells. C. Do not have specific receptors (T-cell receptors) on their surface for antigen recognition. D. Are involved in cell-mediated immunity. E. Participate in suppression of the immune response |
.C. Do not have specific receptors (T-cell receptors) on their surface for antigen recognition.
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26. A formula-fed 6-weeks male child is exposed to his sister, who has chicken pox (Varicella-Zoster). The child does not develop signs of chicken pox (V-Z). Her mother had infection due to V-Z virus three years ago. Which class of immunoglobulin has the child acquired from the mother in utero that protected him from the V-Z virus infection?
A. IgA B. IgD C. IgG D. IgM E. IgE |
.C. IgG
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27. All of the following prevent pathogens from entering the body, except:
A. Tears B. Mucus C. Red blood cells D. Sweat glands |
.C. Red blood cells
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28. Which of the following structures is NOT found in the Gram negative-bacteria but found in Gram positive?
A. Cytoplasmic membrane B. Periplasmic space C. Lipopolysacchride D. Peptidoglycan E. Teichoic acid |
.E. Teichoic acid
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29. Which is the first human viral disease to be discovered?
A. Small Pox B. Yellow fever C. Influenza D. Rabies |
. Yellow fever
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30. An example of an enriched medium is:
A. Nutrient agar B. Blood agar C. Nutrient broth D. All of the above |
.B. Blood agar
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31. The temperature (in Centigrade) achieved in the autoclave for sterilization of materials is approximately:
A. 100 B. 105 C. 110 D. 120 |
.D. 120
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32. In the fall of 2001, a series of letters containing spores of Bacillus anthracis were mailed to the members of the media and to the US senate offices. That resulted in 22 cases of anthrax and 5 deaths. The heat resistance of bacterial spores, such as those of B. anthracis, is due in part due to the presence of:
A. D-Glutamic acid B. Diaminopimeiic acid C. Lipid A D. Calcium dipicolinate |
.D. Calcium dipicolinate
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33. A 0.01 ml quantity of 1:10 dilution of a mid-stream urine sample is plated on MacConkey agar. After 24 hrs. incubation at 370 C, average count of three plates give 300 colony forming units (CFU) of Escherichia coli. What is the number of E. coli present in I ml of the urine sample?
A. 3,000 B. 30,000 C. 300, 000 D. 100.000 |
.C. 300, 000
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34. Antimicrobial therapy can decrease the population of susceptible bowl flora and permit excessive multiplication of relatively resistant colonic bacteria. Which one of the following species can proliferate excessively and produce a toxin that causes diarrhea?
A. Escherichia coli B. Clostridium difficile C. Bacteroides fragilis D. Enterococcus fecalis E. Staphylococcus epidermidis |
.B. Clostridium difficile
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35. An outbreak of sepsis caused by Staphylococcus aureus has occurred in the newborn nursery. You are called upon to investigate. According to your knowledge of the normal flora, what is the MOST likely source of the organism?
A. Colon B. Throat C. Nose D. Mouth |
C. Nose
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36. Incubation period of an infectious disease is defined as:
B. The period from the point of first contact with the pathogenic organism until the point of appearance of symptoms of infection C. The period required to eliminate the infection from the patient D. The doubling time of the pathogenic bacterium causing the disease. E. The period for which the patient continues to harbor the pathogenic organism after recovery F. None of the above |
.B. The period from the point of first contact with the pathogenic organism until the point of appearance of symptoms of infection.B. The period from the point of first contact with the pathogenic organism until the point of appearance of symptoms of infection
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37. Which of the following statements regarding exotoxins is WRONG?
A. Exotoxins are polypeptides B. Exotoxins are more easily inactivated by heat than are endotoxins C. Exotoxin are less toxic than the same amount of endotoxins D. Exotoxins can be converted to toxoids |
.C. Exotoxin are less toxic than the same amount of endotoxins
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38. Several college students in an American university develop watery diarrhea, nausea, vomiting and abdominal cramps 6-8 hrs. after eating hamburgers and salads in a local restaurant. Food poisoning due to Staphylococcus aureus is suspected. Which of the following media should be used, that would function both as a selective and differential medium for isolation of S. aureus from the incriminated foods and its presumptive identification?
A. Blood agar B. MacConkey agar C. Mannitol salts agar D. Chocolate agar |
.C. Mannitol salts agar
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39. A 5 year old boy has a productive cough and a specimen is forwarded to the laboratory for detection of the suspected agent, Hemophilus influenzae.
Select the culture medium which would be most appropriate to isolate Haemophilus influenzae from this patient. A. Blood agar B. Chocolate agar C. MacConkey agar D. Mannitol salt agar |
..B. Chocolate agar
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40. A culture of a midstream urine sample from a patient of urinary tract infection yields numerous pink colored colonies on MacConkey agar. The organism is most likely to be:
E. Escherichia coli F. Proteus mirabilis G. Streptococcus fecalis H. Pseudomonas aeruginosa |
.E. Escherichia coli
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41. If an individual is genetically unable to make J chains, which immunoglobulin (s) would be affected?
A. IgG B. IgM C. IgG and IgM D. IgA E. IgA and IgM |
.E. IgA and IgM
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42. Which of the following can serve as antigen presenting cells?
A. T-cells. B. Macrophages C. Eosinophils D. Kupfer cells |
A. T-cells.
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43. Until the 1970s, the tonsillectomies were routinely performed on children with swollen tonsils. The procedure has lost its wide-spread appeal as we have learnt the important role of mucosal-associated lymphoid tissue (MALT) in the protective immune response. What is the major immunoglobulin produced by the MALT?
A. A dimeric immunoglobulin with secretory component B. A monmeric immunoglobulin that crosses the placenta C. A monmeric immunoglobulin bound by the mast cells D. A monmeric immunoglobulin that opsonizes E. A pentmeric immunoglobulin that activates the complement |
..A. A dimeric immunoglobulin with secretory component
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44. The antibiotic penicillin is a small molecule that does not induce antibody formation. However, penicillin binds to serum proteins and forms a complex that in some people induces antibody formation resulting in an allergic reaction. Penicillin is therefore:
A. An antigen B. Hapten C. An immunogen D. Both an antigen and a hapten E. Both an antigen and an immunoglobulin |
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45. The human immunodeficiency virus interacts with which of the following cell-surface molecules to gain entry into cells of the immune system:
A. CD19 B. CD4 C. CD8 D. CD40 ligand E. CD5 |
.B. CD4
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46. Which is correct for a secondary immune response?
A. Faster than a primary response B. Larger than a primary response C. Longer lasting than a primary response D. More likely to result in increased adaptive immunity than a primary response E. All of the above |
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47. The antibiotic penicillin is a small molecule that does not induce antibody formation. However, penicillin binds to serum proteins and forms a complex that in some people induces antibody formation and results in an allergic reaction. Penicillin is therefore:
A. An antigen. B. A hapten. C. An Immunogen. D. Both an antigen and a hapten. E. both an antigen and an immunogen |
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48. Serological identification of bacteria is based on the presence of specific antigens in:
A. Cell wall B. Flagella C. Capsule D. All of the above E. None of the above |
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49. The bacterium which has not been cultured in vitro either on agar medium or in cell culture is:
A. Treponema pallidum B. Mycoplasma species C. Chlamydia species D. Rickettsia rickettsiae |
.A. Treponema pallidum
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50. Jenner observed that milkmaids who were infected with cowpox were later immune to smallpox infections. This is an example of a(n)
A. Acquired immunity of barrier skin cells B. Active immunization with a non-related organism that causes similar symptoms. C. Innate immunity of milkmaids to smallpox. D. Memory response to a cross-reactive antigen. E. Passive immunization from contact with cow's milk antibodies |
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51. The medium used for isolation and maintenance of mycobacteria is:
A. Mueller Hinton agar B. Lowenstein-Jensen agar C. Mueller tellurite agar D. MacCaonkey agar |
.B. Lowenstein-Jensen agar
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52. Which of the following is chelating compound secreted by some bacteria for Fe-import?
A. Transferrin B. Lactoferrin C. Catchecols D. Hydroxamates E. Catchecols and hydroxamates |
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53. Which of the following is a filamentous Gram positive acid-fast to partially acid-fast which bacterium that breaks in to rods and cocci?
A. Mycobacterium tuberculosis B. Mycobacterium leprae C. Nocardia species D. Actinomyces |
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54. A species or genetic strain requiring one or more complex organic nutrients (such as amino acids, nucleotide bases, or enzymatic cofactors) for growth is designated as:
A. Autotroph B. Heterotroph C. Auxotroph D. Organotroph |
.C. Auxotroph
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