Wells reviewer ---Microbiology

1. The initiation of carious lesion by microorganisms ensues when

1. All the microorganisms are nonviable
2. Hypovitaminosis is present
3. Fermentable carbohydrate is present
4. There is excessive fluoride in the enamel
2. Which of the ff substances are generally most readily usable as a source of energy for
heterotrophic bacteria?
1. Lipids
2. Proteins
3. Carbohydrates
4. Vitamins
3. Obligate autotrophs require
1. Inorganic material for growth
2. Living tissue for growth
3. Organic substrates and darkness for growth
4. Organic substrates and ultraviolet light for growth
4. The interferences by a chemical agent with the normal reaction between an enzyme and
its specific substrate is
1. Chemical antagonism
2. Coagulation
3. Oxidative fermentation
4. Tyndallization
5. Certain oral bacteria may obtain energy by means of
a. Anaerobic dissimilation of sugars
b. Fermentation of carbohydrates
c. Synthesis of polysaccharide polymers
d. Oxidation of sugars
e. Hydrolysis of nucleic acids

1. A, b,d
2. A,b,c
3. B,d,e
4. A,c,e
5. A,d,e
6. The observed increase in glycogen in the epithelium during marginal gingivitis may be
associated with
1. Bacterial collagenase
2. Salivary amylase
3. Bacterial hyaluronidase
4. Vitamin c deficiency
5. None of the above
7. Bacteria that can satisfy their energy requirements by oxidation of substances not
containing carbon are
1. Photoheterotrophs
2. Mesophiles
3. Saprophytes
4. Autotrophs
5. Thermotrophs
8. Bacteria that grow optimally between 25- 40 degrees celcius are termed
1. Thermophiles
2. Psychrophiles
3. Mesophiles
4. Cryophiles
9. Microaerophilic organisms demonstrate maximal growth in
1. The complete absence of oxygen
2. The presence or absence of oxygen
3. The presence of free oxygen
4. An amount of oxygen less than that found in the air

10. The genus Clostridium is distinguisged from the genus Bacillus primarily in that the
former is
1. Aerobic
2. Anaerobic
3. Parasitic
4. A spore-former
5. Coccus
11. In bacterial induction the microorganisms
1. Elaborates a specific enzyme only when the substrate is present in the medium
2. Elaborates a specific enzyme irrespective of the substrate
 3. Elaborates products that inactivate the enzyme
4. Releases preformed endotoxins
5. None of the above
12. The bacterial lag phase
a. Is required for microbial adaptation to a new environment
b. Is dependent on the size of the inoculums, within limits
c. Is the phase in which the number of organisms actively dividing equals the
number of organisms lysing
d. May be prolonged by certain antibiotics
e. Immediately follows the phase of exponential growth
1. A,b,d
2. B,c,d
3. A,b,e
4. B,d,e
5. A,c,e

13. Obligate anaerobic bacteria

1. Require oxygen for their growth
2. All contain catalase
3. Are killed in the presence of oxygen
4. Produce spores that cannot tolerate the presence of oxygen

14. The initiation of a carious lesion is thought to be the result of

1. Chelation of enamel calcium
2. Decalcification of enamel by acidogenic bacteria
3. Degradation of enamel proteins
4. Colonization of the oral cavity by lactobacilli
5. Aerobic degradation of levans

15. Which of the ff chemical reactions can be carried out by some bacteria?
a. Breakdown of penicillin
b. Production of oxygen from lactic acid
c. Synthesis of para-aminobenzoic acid
d. Synthesis of dextrans
e. Production of catalase
1. B,c,d,e
 2. A,b,d
3. A,b,c,e
4. C,d,e
5. All of the above
16. Organisms that cause gas gangrene have a metabolism which is predominantly
1. Thermophilic
2. Lipolytic
3. Proteolytic
4. Anaerobic
5. Both 3 and 4
17. Inductive microbial enzymes can be detected
1. Only in the presence of their specific substrate
2. Only with streptococcal species
3. Only as constitutive cell components
4. Most frequently wit anaerobic bacteria
5. None of the above
18. Sucrose is composed
1. Dextrans
2. Levans
3. Glucans
4. Both 1 and 2
5. None of the above
19. The site of the protein synthesis in a bacterium is(are) the
1. DNA
2. Mesosomes
3. Polyribosomes
4. Metachromatic granules
5. Desmosomes
20. Oxidation of pyruvic acid in the Kreb’s cycle by bacteria is an example of
1. Anaerobic respiration
2. Fermentation
3. Aerobic respiration
4. Photosynthesis
5. None of the above
21. The oral microbiota of an edentulous mouth is essentially
1. Aerobic
2. Anaerobic
3. Microaerophilic
4. Facultative
22. In the logarithmic growth phase of a bacterial culture rate of multiplication
1. Is zero
2. Equals death rate
3. Exceeds death rate
4. Is less than death rate
23. The Snyder test measures the
1. Concentration of lactobacilli in saliva
2. Antibiotic activity of saliva
3. Buffering action of saliva
4. Total bacterial acid production
5. All of the above
24. Dextrans produced by Streptococcus mutans possess which of the ff properties?
1. Resistance to oral acids
2. Glycoprotein in nature
3. Polymers of fructose
4. All of the above
5. None of the above
25. Lactobacilli were considered to be among the bacteria capable of inducing the formation
of carious lesion because these bacteria are
1. Present in high concentration in all human mouths
2. The most prevalent microorganisms in the plague
3. Both acidogenic and aciduric
4. The only acid-forming bacteria in the mouth
5. Related morphologically to Streptococcus mutans
26. Research on experimental caries in gnotobiotic animals has indicated that the majority of
oral microorganisms capable of producing smooth surface dental caries with high
carbohydrate dies are species of the genus
1. Veillonella
2. Streptococcus
3. Fusobacterium
 4. Lactobacillus
5. Actinomyces
27. Forty lactobacillus colonies were counted on a Rogosa agar plate spread with 0.1 ml of a
1:5 dilution of a saliva sample. How many lactobacilli would be present in 1ml of a the
patient’s undiluted saliva?
1. 500
2. 1000
3. 2000
4. 6000
5. 50,000
28. The deposition of salivary calculus may be initiated by filamentous bacteria which
produce a proteinaceous niduss about which are deposited
1. Calcium phosphates
2. Calcium carbonates
3. Ammonium urates
4. Calcium oxalates
29. Bacteria whose optimum temperature for growth is 15-20 degrees celcius have been
termed
1. Autotrophs
2. Mesophiles
3. Chemotrophs
4. Psychrophiles
5. None of the above
30. Penicillin resistance has been shown in certain bacteria to be due to
1. Presence of a hyaluronic acid capsule
2. Presence of the polysaccharide capsule
3. An extracellular enzyme
4. Absence of lipoteichoic acid in the bacterial cell wall
5. Presence of penicillin analogs among the bacterial end products
31. The site of oxidative phosphorylation in bacterial cells is the
1. Nucleus
2. Ribosome
3. Cytoplasm
4. Mitochondrion
5. Cell membrane surface
32. Lysozyme activity is associated with the
1. Hydrolysis of bacterial cell wall mucopolysaccharide
2. Depolymerization of nucleoproteins
3. Activation of plasminogen
4. Inactivation of leukocyte proteases
33. Formation of dental calculus is usually preceded by formation of
1. Dental caries
2. Bacterial plague
3. Calculi in salivary glands
4. A high calcium phosphate concentration in saliva
5. All of the above
34. The phenomenon in which enzymatic activity is demonstrable or increase when an
organism is cultivated in the presence of a given substrate but disappears or decreases
when the substrate is removed is known as
1. Mutation
2. Recombination
3. Transduction
4. Transformation
5. Adaptive enzyme formation
35. A quantitative study of the lactobacillus count in a patient’s mouth would best be made
by
1. Agar pour plate counts using “selective lactobacillus” medium.
2. The colorimeter method using agar shake cultures
3. Quantitative chemical titration of the buffering capacity of the patient’s saliva.
4. Accurately determining the acid produced during a 4-hour period by a mixture of
patient’s saliva and glucose
5. Agar pour plate counts using an enriched blood agar medium

36. Most bacterial capsules are composed of

1. Lipopolysaccharides
2. Lipoproteins
3. Dextranases
4. Polysaccharides
5. Lipids
37. Endospores are characteristics of the genera
 1. Clostridium and Mycobacterium
2. Streptococcus and Eschirichia
3. Clostridium and Bacillus
4. Chlamydia and Bacillus
38. With Streptococcus pnemoniae the rough to mucoid transition is associated with the
acquisition of
1. Pili
2. Capsule
3. Episomes
4. R factor
5. Plasmids
39. A spherical form produced under appropriate conditions from certain bacteria by the
action of penicillin is called an
1. Protoplast
2. Chloroplast
3. Chemotroph
4. Autotroph
5. Auxoplast
40. Thin, surface projections found on certain gram-negative bacteria are formed
1. Volutin
2. Pili
3. Exospores
4. Conidia
41. The term prokaryotic is used to denote
1. All bacteria
2. All mammalian cells
3. Gram positive bacteria only
4. Gram negative bacteria only
5. None of the above
42. Bacteria DNA is associated with
1. Metachromatic granules
2. Acid fastness
3. A positive Feulgen reaction
4. None of the above
43. The cell wall of many gram-positive bacteria can be selectively removed by
1. Spermine
2. Lipoteichoic acid
3. Lysozyme
4. Amylase
5. Para-amino benzoic acid
44. Protoplasts are bacterial cells which
1. Have a cell wall but are free of capsule material
2. Contain a cell wall and capsule
3. Have neither a cell wall nor a capsule
4. Are uniquely sensitive to penicillin
45. Bacterial spores
a. Are unusually dehydrated
b. Are highly refractile
c. Are readily susceptible to disinfectants
d. Are not readily gram-stained
e. Contain polysaccharide capsules
1. A,b,d
2. B,c,e
3. A,c,d
4. C,e
5. B,d,e
46. Which of the ff may serve as the site for bactericidal action by a chemotherapeutic agent?
1. DNA
2. An enzyme required for protein synthesis
3. Cell membrane
4. Cell wall
5. All of the above
47. The presence of a capsule on a bacterium is thought to inhibit
1. Protein synthesis
2. Phagocytosis
3. Antibiotic activity
4. Penetration of ethylene oxide
5. Bacterial pathogenicity
48. The bacterial organelle that functions in a fashion similar to the way the mammalian cell
mitochondrion functions is called an
1. Oxysome
2. Polyribosome
3. Ribosome
4. Mesosome
5. Lysosome
49. The appearance of flagella distributed over the entire bacterial cell surface is known as
1. Lophotrichous
2. Monotrichous
3. Peritrichous
4. Amphitrichous
50. Hairlike filaments extending from bacterial cells are called
1. Pili
2. Fimbriae
3. Cilia
4. All of the above
5. Both 1 and 2
51. The rigid cell wall of gram-positive bacteria is chemically characterized as
1. Murein
2. Peptidoglycan
3. Glycopeptides
4. Mucopeptides
5. All of the above
52. Cytoplasmic granules composed of acid-insoluble polymetaphosphate and found as
inclusions in Corynebacterium diptheriae are called
1. Plasmids
2. Metachromatic granules
3. Babes-Ernst granules
4. Both 1 and 2
5. Both 1 and 3
53. A major distinction between prokaryotic and eukaryotic nuclei is that
1. The prokaryotic nucleus also contains RNA
2. The prokaryotic nucleus is not surrounded by a defined membrane
 3. The eukaryotic nucleus is not surrounded by a defined membrane
4. Plasmids are components of eukaryotic nuclei
54. Bacteria classified as spirochetes include which of the ff genera?
a. Borrelia
b. Clostridium
c. Leptospira
d. Treponema
e. Fusobacterium
1. A,c,d
2. B,c,d
3. B,d,e
4. A,b,e
5. A,d
55. The component of the bacterial cell that functions as an osmotic permeability barrier is
the
1. Cytoplasmic membrane
2. Cell wall
3. Capsule
4. Lipopolysaccharide
5. Teichoic acid

56. It is characterized of exotoxins that they

a. Are antigenic
b. Cause local or systemic reactions when injected into animals
c. Are found outside that intact bacterial cell
d. Combine with specific antibody
e. Chemically are protein
1. A,b
2. A,b,c
3. B,d,e
4. C,e
5. All of the above
57. The smooth to rough colony variation of the pneumococci is accompanied by the loss of
the
1. Nucleus
2. Capsule
 3. Flagella
4. Inclusions or granules
5. Pili
58. The function of bacterial RNA appears to be
1. Control of protein synthesis
2. Storage of genetic information
3. To provide rigidity in the cell wall
4. Storage of high-energy phosphate in diester linkage
5. Regulate oxidation-reduction reactions in the microsomes of the cytoplasm
59. Which of the ff substances is a bacterial virulence factor in streptococci?
1. M protein
2. Flagella
3. Lactic acid
4. Beta-galactosidase
5. Spores
60. The most distinguishing characteristics of bacterial genes include
1. Self-duplication and mutability
2. Haploid and diploid generations
3. Pathogenicity and growth inhibition
4. Protein and phospholipid composition
5. All of the above
61. The ability of pathogenic staphylococci to induce the formation of a plasma clot requires
release of the enzyme
1. Amylase
2. Fibrinolysin
3. Coagulase
4. Lysozyme
5. Phospholipase
62. A characteristic lab test used to distinguish Streptococcus pneumonia from other alpha-
hemolytic streptococci is
1. Growth on blood agar plates
2. Solubility in bile salts
3. Growth under aerobic conditions
4. All of the above
 5. None of the above
63. Primary differentiation between pathogenic and non-pathogenic enteric bacteria can be
made on the basis of
1. Gas production
2. Liquefaction of gelatin
3. Glucose fermentation
4. Lactose fermentation
5. Both 1 and 2
64. Exoenzymes produced by pathogenic bacter may degrade host
1. Polysaccharides
2. Collagen
3. Proteins
4. Nucleic acids
5. All of the above
65. The oxidase test is employed in the laboratory indentification of
1. Nisseria
2. Streptococci
3. Staphylococci
4. Bacillus
5. Both 1 and 3
66. Streptococcus salivarius can be recognized by its distinctive colony on agar containing
high concentrations of
1. Lactose
2. Sucrose
3. Xylitol
4. Sorbitol
5. Eosin and methylene blue
67. A feature that distinguishes enterococci from the other three groups of streptococci is the
1. Tolerance of enterococci to 6.5% NaCl
2. Ability of enterococci to grow at 10 degrees celcius
3. Ability of enterococci to grow at 45 degrees celcius
4. Production of catalase by enterococci
5. Production of beta hemolysis on blood agar plates by enterococci
68. The acid fast staining procedure would be used to indentify _______ species.
 1. Mycobacterium
2. Actinomyces
3. Staphylococcus
4. Bacillus
5. Treponema
69. Differentiation between Proteus vulgaris and Eschirichia coli may be accomplished by
using the
1. Coagulase test
2. Urease test
3. Fermentation of lactose
4. Production of the thick capsules
5. Gram stain
70. The anaerobic bacteria which forms black colonies on blood agar medium and is cultured
from the gingival sulcus is
1. Beta-hemolytic streptococci
2. Streptococcus mutans
3. Streptococcus salivarius
4. Bacteroides melaninogenicus
5. Lactobacillus acidophilus
71. Intracellular collagenase production is associated with member of the genus
1. Streptococcus
2. Lactobacillus
3. Mycobacterium
4. Borrelia
5. Bacteroides
72. The etiologic agents for all of the ff diseases have been cultivated in vitro except
1. Actinomycosis and yaws
2. Leprosy and syphilis
3. Gonorrhea and tuberculosis
4. Malaria and primary atypical pneumonia
5. Impetigo and whooping cough
73. Which of the ff laboratory tests is used to distinguish Streptococcus mutans from other
oral streptococci?
1. Fermentation of mannitol and sorbitol
 2. Production of extracellular polysaccharides
3. Gram reaction
4. Colonial morphology on chocolate agar
5. Growth on blood agar
74. All of the ff techniques used in the anaerobic cultivation of bacteria except
1. Enriched semisolid media in deep tubes
2. Removal of oxygen by combustion
3. Chemical absorption of oxygen
4. Displacement of air by an inert gas
5. Streaked nutrient agar plates
75. Which of the ff substances is not produced by streptococci?
1. Coagulase
2. Hemolysin
3. Erythrotoxin
4. Capsules
5. Hyaluronidase
76. Differentiation of common air-borne fungi from bacteria on solid media can usually be
made most rapidly by examination or study of
1. Colony form
2. Cell morphology
3. Antigen-antibody reaction
4. Fermentation reactions
5. Pathogenicity tests
77. In a single mixed culture containing equal concentrations of Stapylococcus aureus,
Bacillus globigii and Eschirichia coli, the fact that three distinct species were present
could be determined most rapidly by
1. Agglutination with specific serums
2. Examining a gram-stained slide
3. Fermentation tests
4. Mouse inoculation
5. Plating on nutrient agar
78. The addition of paradimethylaminobenzaldehyde to a broth culture sometimes results in a
pink color which indicates formation of
1. Acid
2. Base
 3. Peptone
4. Indole
5. Amino acids
79. The coagulase test is
1. Based upon the production of fibrinolysin by the organism
2. Negative in patients with vitamin K deficiency
3. Used with streptococcus infections
4. Positive in syphilitic patient
5. Used as an aid in the establishment of the virulence of certain bacteria.
80. A gram-positive coccus isolated from saliva, which shows small greening colonies
aerobically on blood agar, is bile insoluble and induces no observable effect after being
injected intraperitoneally into a mouse, is likely to be
1. Diplococcus pneumoniae
2. Staphylococcus aureus
3. Streptococcus mitis
4. Streptococcus pyogenes
5. Veillonella alcalescens
81. An organism seen principally intracellularly in pus cells in a certain body fluid or
exudates, and growing on chocolate agar plates on a Co2-containing atmosphere but not
under more common growth conditions likely to be a member of the genus
1. Actinomyces
2. Corynebacterium
3. Hemophilus
4. Mycobacterium
5. Neisseria
82. In the serum of persons with a variety of inflammatory diseases a diagnostic protein may
be found which is called
1. M protein
2. C-reactive protein
3. Beta-globulin
4. A plasminogen
83. A bacterium which will produce helatinase only when gelatin is present in medium is an
example of
1. Nongenetic variation
2. Genetic variation
 3. Permanent variation
4. Mutation
84. Streptococcus pneumonia and Streptococcus mitis can be differentiated by
1. Inulin utilization and coagulase tests
2. Coagulase nad mannitol utilization tests
3. Bile solubility and mannitol utilization tests
4. Bile solubility and inulin utilization tests
85. The most reliable test used in the diagnosis of syphilis is the
1. CF
2. Kahn
3. FTA
4. VDRL
5. Wassermann
86. Bacteria of the genus Mycobacterium are considered acid-fast because they
1. Stain blue in spite of the acid
2. Grow in the presence of weak acids
3. Decolorize rapidly in weak mineral acids
4. Resist decolorization by dilute mineral acids
5. Produce acid rapidly in artificial culture media
87. The best method for identifying a pathogenic staphylococcus in cases of infection
suspected to have originated from a patient with osteomyelitis is by means of
1. Coagulase testing
2. Blood agar medium
3. Antibiotic sensitivity testing
4. Bacteriophage typing
5. Chromogenesis
88. To determine bacteriologic purity of metropolitan water supplies, sanitary engineers
routinely check the water for the presence of
1. Escherichia coli
2. Salmonella typhosa
3. Shigella dysenteriae
4. Entamoeba histolytica
5. Staphylococcus aureus
89. Pathogenic staphylococci are unusually
 1. IMVIC ++--
2. IMVIC --++
3. Mannitol-negative
4. Coagulase-positive
5. C-carbohydrate positive
90. Which of the ff is least likely to be characteristic of Clostridium tetani?
1. Bacillus
2. Acid-fast
3. Anaerobic
4. Gram positive
5. Spore former
91. The Frel test is an aid in diagnosing
1. Syphilis
2. Psittacosis
3. Lymphogranuloma venereum
4. Atypical primary pneumonia
5. None of the above
92. Treponema pallidum is in part characterized by the fact that it
1. Remains viable in dried body exudates
2. Is able to survive outside the host’s body for long periods of time
3. Is capable of growth only intracellularly
4. Is not readily stained by the common bacterial stains
5. None of the above
93. Microbial growth may be estimated quantitatively by determining
1. Cell nitrogen
2. Cell dry weight
3. Culture turbidity
4. Culture oxygen consumption
5. All of the above
94. A test organism used in the phenol coefficient test is
1. Escherichia coli
2. Salmonella typhosa
3. Serratia marcescans
4. Streptococcus salivarius
95. A laboratory procedure useful in diagnosing of ANUG?
1. Tissue culture
2. Animal inoculation
3. Complement fixation
4. Slide precipitation
5. Dark field examination
96. Examples of extrachromosomal genetic elements in bacteria include the
1. Sex factor
2. R factor
3. Coenzyme I factor
4. Penicillinase plasmids of staphylococci
5. All of the above
97. The biologic functions of bacteriophages in infectious disease have been shown to
include
a. Conversion to toxigenicity of Corynebacterium diphtheria
b. Neutralization of exotoxins by antitoxin
c. Transduction in salmonella
d. Detailed classification of pathogenic staphylococci
e. Release of endotoxins by Pseudomonas aeruginosa

98. Bacterial mutation may be induced by changes in the

1. RNA nucleotide sequence
2. DNA nucleotide sequence
3. Cell wall teichoic acid
4. Ribosomes
5. Metachromatic granules
99. Lysogenic conversion is thought to be responsible for toxin production in
1. Actinomycosis
2. Gonorrhea
3. Moniliasis
4. Tuberculosis
5. None of the above
100. The form of bacterial genetic transfer which is susceptible to DNase and does not
require cell-to-cell contact is
1. Cell attachment
2. Conjugation
 3. Transformation
4. Transduction
101. Rough pneumococci grown in the presence of DNA from smooth pneumococci
develop capsules. This is known as
1. Mutation
2. Conjugation
3. Translation
4. Transduction
5. Transformation
102. Avirulent Corynebacterium diphtheria can be converted to the virulent form by
1. Plasmids
2. Transfer of F factors
3. Specific bacteriophage
4. Purified diphtheria toxin
5. DNA from a toxigenic culture
103. Determinants of toxigenicity in the diphtheria bacillus include
1. Low oxidation-reduction potential during growth
2. Lysogenicity
3. The presence of a capsule on the bacillus
4. The presence of red blood cells in the growth medium
104. DNA in the genetic material in
1. Capsular swelling
2. Metachromatic granules
3. Replica plating experiments
4. Pneumococcal capsular transformation
5. Ultraviolet light irradiation experiments
105. The transfer of genetic determinants in a cell free, phage free
DNA preparation is
1. Mutation
2. Adaptation
3. Conjugation
4. Transduction
5. Transformation
106. Virulent phages differ from temperate phages in the
 1. Tendency to induce a lysogenic state
2. Specificity of their hosts
3. Manner in which they are released
4. Presence of RNA in the mature virus
5. Manner in which they line up before being released
107. Infectious drug resistance is a term used to describe the behavior of which of the
ff?
1. Vi factors
2. Resistance transfer factors
3. Transformation viruses
4. All of the above
108. Sexual recombination in bacteria is illustrated by
1. Transduction among Salmonella species
2. Transformation by DNA among pneumococci
3. Lysogeny in Cornybacterium diphtheria
4. Conjugation among Escherichia coli strains
109. The chemical constituents of bacteria and viruses which are most sensitive to
ultraviolet radiation are
1. Nucleic acids
2. Proteins
3. Lipids
4. Carbohydrates
5. Fatty acid
110. An exchange of genetic material between bacteria takes place in which of the ff
phenomena?
1. Selection
2. Transformation
3. Transduction
4. Recombination
5. 1,2,4
6. 2,3,4
111. Heat sensitive materials such as plastic retractors and rubber base appliances may
be sterilized by means of
1. Quaternary ammonium compounds
2. Ethylene oxide
 3. Ethyl alcohol
4. Autoclaving
5. None of the above
112. The mechanism of action of quaternary ammonium compounds is against the
1. Metachromatic granules
2. Cytoplasmic membrane
3. Cell wall
4. Flagella
5. DNA
113. Generally, resistance of bacterium to heat is influenced by time and temperature
employed in growth of the culture. Another factor is the ability of the organism to
1. Form spores
2. Withstand acid pH
3. Produce protoplasts
4. Undergo transformation
5. Grow at elevated temperatures
114. For hand disinfecting in the laboratory a cationic detergent which has a phenol
coefficient of 25 is used in a dilution of 1:2000. A substance with similar chemical and
physical properties has a phenol coefficient of 5. Which of the ff concentrations of the
latter should be used for the same purpose?
1. 1:125
2. 1:250
3. 1:400
4. 1:1000
5. 1:10.000
115. Quaternary ammonium compounds are neutralized by
1. Sulfamerazine
2. Cationic detergents
3. Anionic detergents
4. Para-aminobenzoic acid
116. An antiseptic is a chemical agent which
1. Is germicidal when applied to inanimate objects or living tissues
2. Is bacteriostatic
3. Is virucidal when applied to living tissues
4. Either inhibits or kills microorganisms when applied to living tissues
117. Bacterial cell destruction by ultrasonic energy probably results from
1. Levitation
2. Rupture of cell wall
3. Rupture of the nuclear membrane
4. Combination of 1 and 3
5. Combination of 2 and 3
118. The microbe laden aerosols generated by high-speed dental instruments have been
found to cause marked increases in levels of air-borne microorganisms. Such increases
may
1. Pose a moderate health hazard for the dentist butnot the patients
2. Be insignificant because of immunity resistance factors
3. Pose a serious health hazard for subsequent patients but not the dental personnel
4. Constitute a potential health hazard for dental personnel and patient
5. Be a little concern because stresses of aerosolization render the microorganisms
avirulent
119. The efficiency of disinfectants depends upon
1. Concentration of microorganisms
2. Concentration of disinfectants
3. Length of exposure time
4. All of the above
5. None of the above
120. Which of the ff is the best method to avoid serum hepatitis cross infection among
dental patients?
1. Boil all needles and cutting instruments for 5 minutes in water containing antirust
chemicals
2. Use a 2min surgical scrub for hands and all items soiled by blood
3. Soak instruments in a phenolic disinfectant for 20 minutes
4. Autoclave or dry heat sterilize all instruments and objects that come in contact
with tissues.
5. Autoclave or dry heat sterilize those instruments used to treat patients who give a
history of the disease.
121. Ethylene oxide is an agent that
1. Sanitizes
2. Antiseptic
3. Cleanses
 4. Sterilizes
5. Disinfects
122. During one process of pasteurization milk is heated at temperatures
1. Of 100 degrees celcius for 5 minutes
2. Of 142-145 degrees Fahrenheit for 30 minutes
3. Which reduces the level of pathogens
4. Which are sufficient for sterilization
123. Cationic surfactants may inactivate microbial cells because they act on the
1. DNA
2. RNA
3. Cell wall
4. Mitochondria
5. Cytoplasmic membrane
124. If a solution of quaternary ammonium compound is to be used as a disinfectant,
instruments must be thoroughly rinsed because soap
1. Damages the instruments
2. Is toxic to mucous membrane
3. Inactivates the quaternary compound
4. Enhances the action of quaternary compound
125. Detergents kill bacteria by interfering with the function of the cell
1. Wall
2. Nucleus
3. Capsule
4. Membrane
5. Protoplasm
126. Proper pasteurization would most likely kill which of the ff bacteria in any or all
phases its growth?
1. Bacillus anthracis
2. Clostridium tetani
3. Mycobacterium tuberculosis
4. Thermophilic nonspore-formers
127. Sterilized dental instruments are free of all viable
1. Microorganisms
2. Protozoa and spirilla
 3. Fungi and actinomycetes
4. Viruses pathogenic to man
5. Spore forming and nonspore forming vacteria pathogenic to man
128. Of the ff the virus which is most resistant to chemical and physical agents is the
one which causes
1. Mumps
2. Measles
3. Influenza
4. Serum hepatitis
5. Infectious hepatitis
129. Dry heat sterilization of paper points without incineration is accomplished at
1. 121 degrees celcius for 1 hour
2. 200 degrees celcius for 1 hour
3. 100 degrees celcius for 2 hours
4. 160 degrees celcius for 2 hours
130. The most efficient method of sterilization in dental practice is
1. Tyndallization
2. Boiling for 200 minutes
3. Ultraviolet radiation
4. Dry heat at 150 degrees celcius for 2hours
5. Moist heat at 121 degrees celcius for 20 minutes
131. The spores of Clostridium tentani are destroyed by
1. 121 degrees celcius for 20 min
2. 121 degrees celcius for 10 min
3. 100 degrees celcius for 10 min
4. 62 degrees celcius for 30 min
132. In the conc usually applied for sterilization purposes ethylene oxide is preferable
to formaldehyde because it is
1. Less toxic
2. More penetrating
3. More readily polymerized to an active form
4. Less likely to form an explosive mixture with air
133. The best method of storing sterile instruments is to
1. Leave packages in autoclave for temporary storage
 2. Keep items between sterile towels in a dust free dental cabinet
3. Place items in chemical disinfecting solution until ready to use
4. Keep items in the same packages as were prepared for sterilization
134. Exposure to ultraviolet irradiation is an ineffective means of sterilizing
instruments because
a. Bacterial spores require long exposure
b. All surfaces of the object must be adequately exposed
c. Ultraviolet rays will not pass through glass
d. Viruses are not affected by ultraviolet irradiation
1. A,b,c
2. Ab,d
3. A,c,d
4. B,c,d
5. All of the above
135. The biologic standard used to test for efficacy of sterilization involves the use of
1. Streptococcus pneumonia
2. Spore of a harmless bacillus
3. Infectious hepatitis virus
4. Spores of Clostridium tetani
5. None of the above
136. Practical methods of sterilization that are in general use in hospitals and clinics
are
1. Autoclaving
2. Dry heat sterilization
3. Gas sterilization
4. All of the above
5. None of the above
137. The term cold sterilization has been employed in the past to refer to
1. Chemical disinfection
2. Exposure to low temperature steam
3. Physical methods of sterilization
4. Prolonged exposure to – 20 degrees celcius
5. None of the above
138. According to what is known about the basic structure of most viruses it is
presumed that they are
 1. Easily destroyed by the application of moist heat
2. Difficult to destroy by the application of moist heat
3. Never destroyed by the application of moist heat
4. Never destroyed because they are not living
139. A phenol coefficient of 5 for an unknown disinfectant would indicate that
1. The disinfectants are equally effective
2. Phenol is five times more effective against bacteria than the unknown compound
3. The unknown disinfectant is five times as effective as phenol against all bacteria
4. Under the test conditions a dilute solution of phenol is more effective than the
concentrated unknown
5. None of the above
140. A positive attribute of the bisphenol disinfectant is that it
1. Kills hepatitis virus
2. Has a cumulative effect with repeated usage
3. Leaves the skin oils intact
4. Is very effective against Mycobacterium tuberculosis
141. Which of the ff has the narrowest effective antimicrobial range?
1. Soap
2. 70% isopropanol
3. Cresols
4. Iodophors
5. Glutaraldehydes
142. Hepatitis virus are not destroyed by
1. Autoclaving
2. 70% isoprophy alcohol
3. Benzalkonium chloride
4. Both 2 and 3
143. Which of the ff is/are considered disadvantages in the application of dry heat as a
sterilizing agent?
1. Does not destroy hepatitis virus
2. Dulls instrument cutting edges
3. Requires excessive time
4. All of the above
144. The destruction of microorganisms on living tissues, as long as there is contact
between the tissues and the antimicrobial agent, denotes
 1. Sanitization
2. Antisepsis
3. Sterilization
4. Both 2 and 3
5. None of the above
145. Bacterial spores are generally resistant to the antimicrobial effects of
1. Iodophors
2. Quaternary ammonium compounds
3. Glutaraldehydes
4. All of the above
146. Which of the ff limits the effectiveness of quaternary ammonium compounds in
disinfection?
1. Limited antimicrobial range
2. Poor penetration of organic debris
3. Both 1 and 2
4. None of the above
147. The term bactericidal is used to denote
1. The ability to kill bacteria
2. The ability to inhibit growth of bacteria, but not kill them
3. Most nonionic detergents
4. None of the above
148. Glutaraldehydes are effective against
1. Gram positive bacteria
2. Acid fast bacilli
3. Spores
4. Gram negative bacteria
5. All of the above
149. A major drawback to the use of boiling water (moist heat) for sterilization is its
1. Inability to kill vegetative bacteria
2. Corroding of carbon steel instruments
3. Ineffectiveness against gram negative bacteria
4. Denaturation of protein
5. Poor penetrating power
150. The method of choice for the sterilization of clinical thermometers is
 1. Autoclave
2. Chemical sterilization
3. Dry heat
4. A clinical thermometer need not be cleaned each it is used.
151. Rickettsiae and chlamydiae are characterized by all of the ff except
1. They contain both DNA and RNA
2. Their growth can be inhibited by antimicrobial drugs
3. They multiply in bacterial cells
4. Both 1 and 2 only
5. Both 2 and 3 only
152. Which of the ff reproduce mainly by spore formation, elaborate no endotoxin, and
grow on Sabouraud’s medium?
1. Rickettsiae
2. Fungi
3. Bacteria
4. Mycoplasmas
5. Viruses
153. On of the distinguishing characteristics of all viruses is the
1. Absence of the nucleic acids
2. Ability to grow in cell free medium
3. Adaptability to external environment
4. Constant route of infections
5. Failure to grow in the absence of living cells
154. Staphylococci are characteristically grouped in
1. Serpentine chains
2. Short chains
3. Tetrads
4. Irregular clusters
5. Palisade arrangements
155. Most rickettsial diseases are severe human infections because the organisms
1. Produce potent exotoxins
2. Aare particularly destructive to cutaneous tissues
3. Are primarily neurotropic and cause extensive damage in certain CNS centers
 4. Have a predilection for endothelial cells and smooth muscle cells of small blood
vessels
156. Fungi produce disease in man by
1. Induction of hypersensitivity to mycotic antigens
2. Enzyme production
3. Exotoxin production
4. Endotoxin production
5. Stimulation of high antibody titers

157. Gram positive microorganisms generally

1. Require few amino acids
2. Are quite susceptible to basic dyes
3. Show immunolysis
4. Are not susceptible to penicillin
158. A dark field microscope would be useful for the examination of saliva for
1. Salmonella spp.
2. Borrelia spp.
3. Mycobacterium spp.
4. Corynebacterium spp.
159. The term pleomorphism is properly applied to organisms which
1. Possess numerous flagella
2. Are encapsulated in a thick mucoid membrane
3. Are elliptical or ovoid in shape
4. Vary in size and shape in actively growing culture
5. Exhibit an unusual uniformity in staining reactions
160. Which of the ff fungi is yeastlike and will not grow in mycelia form?
1. Coccidiodes immitis
2. Histoplasma capsulatum
3. Sporothrix schenckii
4. Cryptococcus neoformans
5. Blastomyces dermatitidis
161. Infection with viruses differs from infection with nonviral agents in that
1. Viruses induce infection through the action of their nucleic acids
2. Viruses do not multiply in the nucleus of host cells
 3. Antibodies capable of conferring immunity against nonviral agents can often be
produced in response to a viral agent
4. Clinical symptons of virus infections are now thought to be associated with the
formation of virus crystals in vivo.
162. Characteristics of viral infections generally include the fact that
1. Infections yield readily to chemotherapy
2. Agents are primarily human parasites
3. Infections are readily treated with immune serum
4. The agents multiply intracellularly
163. The characteristics used in classification of fungi are
1. Septate or nonseptate mycelia
2. Vegetative or aerial mycelia
3. Sexual or asexual spores
4. Pigmentation
5. All of the above
164. Rickettsia
1. Produce no immunity
2. Are plant pathogens
3. Are transmitted only by mosquitoes
4. Develop only within living cells
5. Are too small to be seen with the light microscope
165. Which of the ff is pathogenic for man in one of its diphasic cycles?
1. Fungi
2. Algae
3. Viruses
4. Bacteria
5. Rickettsiae
166. Most members of the herpes viruses have an affinity for ___cells.
1. Ectodermal
2. Endodermal
3. Mesodermal
4. Bony
5. Both 2 and 4
167. Spores may be a method of reproduction in certain
 1. Bacteria
2. Fungi
3. Rickettsia
4. Viruses
168. Considering nuclear structure, which of the ff microorganisms is most closely
related to mammalian cells?
1. Bacteria
2. Fungi
3. Rickettsiae
4. Viruses
169. Generally speaking, rickettsial infections are characterized by
1. Fever
2. Headaches
3. Skin rash
4. All of the above
5. None of the above
170. Which of the ff do not have a metabolic scheme of their own?
1. Bacteria
2. Fungi
3. Rickettsiae
4. Viruses
5. 3 and 4
171. Which of the ff are obligate intracellular parasites?
1. Bacteria
2. Fungi
3. Rickettsiae
4. Viruses
5. Both 3 and 4
172. Which of the ff are classified as prokaryotes?
1. Bacteria
2. Fungi
3. Yeasts
4. Viruses
5. Protozoa
173. Insect vectors are very important in the spread of most human diseases caused by
1. Bacteria
2. Fungi
3. Rickettsiae
4. Viruses
174. Which of the ff do not contain both DNA and RNA?
1. Bacteria
2. Fungi
3. Rickettsiae
4. Viruses
5. Both 2 and 4
175. Which of the ff condition tends to decrease the total number of microorganisms in
the oral cavity?
1. Diabetes mellitus
2. Neglect of oral hygiene
3. Complete absence of teeth
4. A decrease in salivary secretion
5. An increase in dietary carbohydrate
176. Amphotericin B, griseofulvin, and nystatin ar often useful in the treatment of
1. Streptococcal infections
2. Fungal diseases
3. Viral diseases
4. Tuberculosis
5. Cancer
177. The principal antibacterial action of penicillin is an impairment of
1. DNA synthesis
2. Histone formation
3. Cell permeability
4. Protein synthesis
5. Cell wall synthesis
178. Penicillin is not routinely used in treatment of
1. Gonococcal infections
2. Salmonella and Shigella infections
3. Streptococcal infections
 4. Anthrax
5. Syphilis
179. Penicillin should be used with care in dentistry because it is
1. Allergenic
2. Bacteriostatic, never bactericidal
3. Compounded inaccurately
4. Toxic in high dosages
5. Toxic to nervous tissue
180. Sulfanilamide acts as a chemotherapeutic agent because it is an enzyme inhibitor
competing for a metabolic intermediate and interferes with the absorption of
1. Para-aminosaniline
2. Nicotinamide adenine dinucleotide
3. Methylglucoside
4. Para-aminobenzoic acid
5. Benzoic acid
181. In opportunistic infections resulting from the use of certain antibiotic drugs
microorganisms implicated as causative agents frequently are
1. Candida albicans
2. Pseudomonas aeruginosa
3. Staphylococcus aureus
4. All of the above
182. Penicillin is preferred for most bacterial infection of the oral cavity because of its
1. Broad spectrum
2. Effect on gram negative bacteria
3. Low toxicity
4. Acidic properties
5. None of the above
183. When equal parts of two antibiotics in combination produce an effect greater than
that obtained by doubling the concentrations of either alone, the effect is
1. Additive
2. Antagonistic
3. Synergistic
4. All of the above
5. None of the above
184. Unless a patient’s hypersensitivity dictates otherwise the antibiotic of choice for
prophylactic therapy covering dental procedures in the patient with a heart valve
abnormality is
1. Penicillin
2. Lincomycin
3. Tetracycline
4. Streptomycin
5. Chlorampenicol
185. Certain bacteriostatic agents, such as the sulfa drugs are known to interfere with
the lethal action of penicillin on bacteria. The most likely general explanation for this
interference is that these agents.
1. Form chemical complexes with penicillin
2. Prevent the uptake of penicillin by bacteria
3. Reversibly inactivate the penicillin sensitive enzymes
4. Make bacteria insusceptible to penicillin by preventing growth
186. Clinically encountered penicillin-resistant staphylococcal mutants are resistant
because they
1. Produce penicillinase
2. No longer have cell walls
3. Are impermeable to the drug
4. Produce a penicillin binding waste product
5. Have an alternate, penicillin insensitive, metabolic pathway
187. Penicillin is inhibitory to the growth of most strains of
a. Streptococcus pyogenes
b. Neisseria gonorrhoeae
c. Treponema pallidum
d. Salmonella typhosa
e. Candida albicans
1. A,b,c
2. B,d,e
3. C,d
4. A,e
5. None of the above

188. Which of the ff antimycotic drugs is utilized most frequently in the treatment of
extensive ringworm infections?
 1. Amphotericin B
2. Nystatin
3. Griseofulvin
4. Sodium iodide

189. Nystatin is most effective against fungal infections when administered

1. IV
2. Intrathecally
3. Intradermally
4. Topically
190. The basic site of action of polyenes is the
1. Nucleus
2. Cell wall
3. Cell membrane
4. Walling off the fungus
191. Which of the ff can be effectively admininistered by the intravenous route in the
treatment of systemic mycoses
1. Amphotericin B
2. Nystatin
3. Griseofulvin
4. Potassium permanganate
192. Which of the ff is a plant alkaloid useful in antineoplastic theraphy?
1. Prednisone
2. 5-fluorouplacil
3. 6-mercaptopurine
4. Methotrexate
5. Vincristine
193. The antineoplastic effects of a plant alkyloids arise from their role in
1. Binding guanidine residues of DNA
2. Blocking cell membrane fractions
3. Mitotic spindle poisons
4. Causing breaks in DNA
5. Both 1 and 3
194. Which of the therapeutic approaches is preferred in the treatment of the most
forms of leukemia?
 1. Surgery
2. Radiotheraphy
3. Chemotheraphy
4. All of the above are employed equally
195. Methotrexate (amethopterin) acts intracellularly as an antineoplastic agent by
1. Inactivating the key enzyme needed to create the active form of folic acid
2. Inhibiting cellular mitosis at metaphase
3. Causing breaks in DNA helical chains
4. Competing for the purine precursors in DNA synthesis
5. Both 3 and 4
196. A pronounced resistance to the chemotherapeutic effects of penicillin is found in
oral and abdominal infections caused by
1. Bacteroides fragilis
2. Group A beta-hemolytic streptococci
3. Peptostreptococci
4. Neisseria
5. All of the above
197. The use of a corticosteroid in a grossly infected pulp may
1. Increase in the inflammatory response
2. Reduce the virulence of the microorganism
3. Enhance the spread of the infecting microorganisms
4. Increase the antibody formation to the infecting bacterium
198. Adverse side-effects of cancer chemotherapy include
1. Alopecia
2. Increased incidence of fungal infections
3. Edema
4. Oral ulcers
5. All of the above
199. The antibiotic which is toxic for the vestibular portion of the 8th cranial nerve is
1. Neomycin
2. Bacitracin
3. Novobiocin
4. Streptomycin
5. Oxytetracycline
200. The antibiotic most likely to be considered for the treatment of a systeminc
infection involving a gram positive organism resistant to penicillin is
1. Nystatin
2. Isoniazid
3. Polymyxin B
4. Erythromycin
5. Streptomycin
201. The mode of action of chemotherapeutic agents such as sulfa drugs is
1. Bacteriolysis
2. Protein denaturation
3. Competitive enzyme inhibition
4. Alteration of cell wall permeability
202. What are the dangers of using antibiotics for the control of dental caries?
1. Disturbance of normal microflora and possible induction of disease
2. Development of resistant microorganisms
3. Induction of allergy
4. All of the above
203. Antimicrobial substances which originate as metabolic products of living
organisms are known as
1. Toxins
2. Enzymes
3. Antibodies
4. Antibiotics
5. Sulfonamides
204. Prolonged antibiotic therapy may predispose an individual to infectious disease
caused by the indigenous oral microorganisms
1. Nisseria sicca
2. Candida albicans
3. Treponema mucosum
4. Streptococcus mitis
5. Fusobacterium fusiform
205. Emetine hydrochloride is used in the chemotherapeutic treatment of
1. Amoebic dysentery
2. Trichomoniasis
3. Malaria
 4. Candidiasis
5. Bacillary dysentery
206. Which of the ff microorganisms is not involved in food-borne disease in man?
1. Candida albicans
2. Clostridium botulinum
3. Salmonella enteritidis
4. Staphylococcus aureus
5. Trichinella spiralis
207. Of the ff, the diseases most likely to be transmitted by raw milk is
1. Whooping cough
2. Tularemia
3. Brucellosis
4. Glanders
208. Serum hepatitis virus is transmitted mainly by
1. Arthropod bites
2. Personal contact
3. The respiratory route
4. Blood or blood products
5. Contaminated drinking water
209. Which of the ff foods should be suspected as the most likely source of a small
epidemic of staphylococcal gastroenteritis which appeared within 4hours after a meal?
1. Mayonnaise
2. Canned tuna
3. Kidney beans
4. Pizza
5. Cheese omelet
210. Mosquito control is an important prophylactic measure in
1. Malaria
2. Dengue fever
3. Yellow fever
4. Viral encephalitis
5. All of the above
211. The rickettsial diseases are spread primarily by
1. Arthropods
 2. Direct contact
3. Droplet infection
4. Contaminated food
5. Contaminated water
212. Type A hepatitis may be spread through the population by infected
1. Oysters and clams
2. Salads
3. Sandwiches
4. Mayonnaise
5. All of the above
213. The control of bubonic plague is related mainly to a decrease in the population of
1. Rats
2. Cows
3. Rabbits
4. Flies
5. None of the above
214. The mumps virus is transferred in humans by
1. Food
2. Feces
3. Flies
4. Wound infection
5. Droplets of saliva
215. A disease unlikely to be spread by the airborne route is
1. Measles
2. Diphtheria
3. Tuberculosis
4. Typhoid fever
5. Whooping cough
216. The type of infection commonly transmitted by blood and blood derived products
is
1. Type A hepatitis
2. Type B hepatits
3. Herpes simplex keratitis
4. Cytomegalovirus
217. The best way to prevent the spread of hepatitis by needles in a dental office is to
1. Not give any injections
2. Scrub needles thoroughly between use
3. Use disposable needles
4. None of the above
218. Measles is transmitted from one person to another via
1. Feces
2. Fomites
3. Insect bites
4. Contaminated water
5. Respiratory droplets
219. The constant low level of a diseases in a given area is termed
1. Pandemic
2. Epidemic
3. Endemic
4. None of the above
220. The ability of the organism to produce disease is called
1. Avirulence
2. Epidemiology
3. Pathogenicity
4. Tolerance
5. None of the above
221. A positive tuberculin test means that the patient
1. Has active tuberculosis
2. Has a subclinical infection
3. Is susceptible to tuberculosis
4. Has an immunity to tuberculosis as a result of a past infection
5. Has a hypersensitivity to the tubercle bacillus and its products
222. Persons having anti A and anti B isoagglutinin in their serum belong to the blood
group
1. A
2. B
3. AB
4. O
223. The reason for heating serum used in the complement fixation test to 56 degrees
celcius for 20-30 minutes is to inactivate
1. Antigen
2. Antibody
3. Complement
4. Any bacteria present
224. The majority of antibodies have a half-life closest to
1. 20 minutes
2. 1 hour
3. 1 day
4. 1 week
5. 1month
225. Desensitization to pollen is accomplished by injecting
1. Histamine and histamine analogs
2. Antihistaminic drugs
3. Pollens or pollen antigens
4. Antibodies specific against pollens
5. None of the above
226. The characteristic lipopolysaccharide-protein antigens of Escherichia,
Salmonella, Shigella and other genera do not act as
1. Agents inducing the Shwartzman reaction
2. Endotoxins
3. Exotoxins
4. Somatic antigens
227. Phagocytosis is enhanced by
1. Ablastins
2. Opsonins
3. Regains
4. Antitoxins
5. Blocking antibiotics
228. A patient experiences papulovesiculation of the hands within 15 min after
administration of penicillin. The reaction may be classified as
1. Delayed reaction
2. “idlike” reaction
3. Immediate reaction
 4. Contact dermatitis
5. Toxic reaction
229. In the Fisher-Race system the antigen most often responsible for the Rh positive
state is called
1. c(lower case)
2. d(lower case)
3. e(lower case)
4. C ( capital)
5. D (capital)

230. A good example of isohemagglutinin is

1. Lysozyme
2. Hemolysin
3. Cold agglutinins
4. Heterophil antibodies
5. Anti-A antibodies
231. In a complement fixation test, antibody in the first system is supplied by
1. Viral or rickettsial suspension
2. Extract of Histoplasma capsulatum
3. Cardiolipin
4. Fresh normal guinea pig serum
5. Serum from the patient to be tested
232. The Fc portion of the antibody molecule is responsible for
1. Stabilizing secretory IgA
2. Antigenic specificity of immunoglobulins
3. Attachment of reaginic antibodies to receptors
4. 1 and 2
5. 2 and 3
233. Human histocompatibility antigens are genetically controlled by the ___locus.
1. H-2
2. HHL
3. H-1
4. HL-A
5. 1 and 3
234. Which of the ff cell types is involved in the induction of both cellular and
humoral immunity?
1. PMNs
2. Plasma cells
3. T lymphocytes
4. B lymphocytes
5. None of the above
235. The major immunologic deficiency in patients with Hodgkin’s disease is
1. B-cell deficiency
2. T-cell deficiency
3. Combined deficiency
4. Deficiency in phagocytosis
5. None of the above
236. Host immunity against most encapsulated pathogenic bacteria is mainly mediated
by
1. Cellular immunity
2. Delayed hypersensitivity
3. Humoral immunity
4. 2 and 3 equally
5. 1 and 2 equally
237. The binding of complement is an important component of
1. Humoral immunity
2. Lymphokine production
3. Arthus reaction
4. 1 and 2
5. 1 and 3
238. The term shock organ refers to which of the ff reactions?
1. Complement fixation
2. Systemic prophylaxis
3. Craft rejection
4. Contact dermatitis
5. Anaphylaxis
239. Which of the ff immunoglobulins reacts with a soluble antigen in serologic
assays?
1. Opsonins
 2. Agglutinins
3. Lysins
4. Precipitins
5. None of the above
240. The antibody class active in human anaphylaxis is
1. IgA
2. IgE
3. IgG
4. IgM
5. IgD
241. The type of graft having the best chance of survival is the
1. Isograft
2. Autograft
3. Allograft
4. Xenograft
242. Which of the ff is no characteristic of IgG?
1. Placental transfer
2. Major anamnestic antibody
3. Isohemagglutinin
4. Skin fixing
5. 3 and 4
243. Acinar cells are important in immunology for their production of
1. IgD
2. Fab fragments
3. Secretory components
4. Lysozyme
5. Complement
244. Neutralization and inactivation of bacterial toxins is accomplished by
1. Delayed hypersensitivity
2. Cellular immunity
3. Humoral immunity
4. 1 and 3
5. 2 and 3
245. When dental local anesthetics are handled immunologically by the body, they are
termed
1. Antibodies
2. Incomplete antigens
3. Complete antigens
4. Toxoids
5. Antibodies
246. Which of the ff is not pharmacologic activities of histamine?
1. Reaginic activity
2. Increase in vascular permeability
3. Smooth muscle constriction
4. Activation of macrophages
5. 1 and 4
247. The antibody class most prevalent in human saliva is
1. Serum IgA
2. IgG
3. IgM
4. Secretory IgA
5. IgD
248. Most of the tooth transplants currently performed in humans are
1. Autografts
2. Xenografts
3. Allografts
4. Isografts
5. Implants
249. The dental implant material which has been shown to allow bone growth right up
to the surface of the implant is
1. Titanium bladevent
2. Anorganic bone
3. Vitreous carbon
4. Polymethylmethacrylate
250. Tissue manifestations of bladevent implants include
1. Biologic acceptance
2. Growth of host bone through implant vents
 3. Formation of fibrous capsular tissue
4. 1,2,3
5. 2 and 3
251. When a Rh-negative mother receives a substance like RhoGAM she is being give
1. Antibodies
2. Antigen
3. Antibiotics
4. Haptens
5. None of the above
252. An individual whose serum contains anti-A isoagglutinins has which blood type?
1. A
2. B
3. C
4. O
5. AB
253. Which of the ff symptoms is consistent with immediate hypersensitive reactions?
1. Complement activation
2. Eythema
3. Neutrophil infiltration
4. Respiratiory distress
5. All of the above
254. Cellular immunity is not active in which of the ff immunologic phenomena?
1. Contact dermatitis
2. First set graft rejection
3. Opsonin production
4. Delayed hypersensitivity
5. Production of macrophage activation factor
255. Individuals that readily develop a number of allergies are termed
1. Desensitized
2. Deficient in IgA
3. Rejectable patients
4. Atopic
256. Which of the ff types of antibodies can coat bacteria and promote phagocytosis of
the microorganism?
 1. Opsonins
2. Precipitins
3. Lysins
4. Agglutinins
5. Neutralizins
257. All of the ff may act as haptens except
1. Procaine
2. Penicillin V
3. Serum proteins
4. Urishiol
5. All of the above may act as haptens
258. IgE can attach to the surface of
1. Erythrocytes
2. Lymphocytes
3. Mast cells
4. Fibroblasts
259. The principal aim of allergic desensitization is to induce the production of specific
1. IgE
2. Secretory IgA
3. IgM
4. IgG
5. Lymphocytes
260. Which of the ff factors are probably involved in human periodontal disease?
1. PMNs
2. Osteoclast activation factor
3. Complement
4. T cells
5. All of the above
261. Most intracellular bacterial infections are controlled by the body through the
mechanisms
1. Cellular immunity
2. Complement activation
3. Hyperacute rejection
4. PMN phagocytosis
 5. 2 and 4
262. Pharmacologically active mediators existing preformed in tissues include
1. Slow reactive substance anaphylaxis
2. Histamine
3. Serotonin
4. Bradykinin
5. 2 and 3
263. The portion of the immunoglobulin molecule that binds specifically with antigen
is the
1. Fc piece
2. Secretory component
3. Papain portion
4. Fab piece
5. None of the above
264. Common antigens employed to test whether patients may develop delayed
hypersensitive skin reactions do not include
1. Candidin
2. Mumps antigen
3. Animal erythrocytes
4. Old tuberculin
5. All of the above are employed routinely for skin testin
265. Dental practitioners have been known to develop allergies against all of the ff
except
1. Rubber gloves
2. Cleaning solutions
3. Eugenol
4. Dental adhesive materials
5. All of the above have been shown to induce hypersensitive reactions
266. The usual source of complement in complement fixation test is
1. Sheep serum
2. Guinea pig serum
3. Rabbit red blood cells
4. Purified lipopolysaccharide from yeast
5. Patient’s serum
267. The antigen used in the tuberculin test is
 a. Purified protein derived from the tubercle bacillus
b. Sterile filtrate prepared from a culture of tubercle bacilli
c. Suspension of heat killed avian tubercle bacilli
d. Suspension of viable human tubercle bacilli
e. The calmet-guerin bacillus
1. A,b
2. A,c
3. B,c
4. B,d
5. B,e
268. Allergy or delayed hypersensitivity may be transferred by
1. Serum
2. Plasma cells
3. Lymphocytes
4. Erythrocytes
5. Monocytes
269. All of the ff are components of the body’s nonspecific defense mechanism except
1. Fibrinolysin
2. Complement
3. Interferon
4. Properdin
5. Lysozyme
270. Immunization against smallpox is usually accomplished by
1. Subcutaneous injections of formalin-killed smallpox virus
2. Subcutaneous injection of formalin-killed vaccinia virus
3. Application of live smallpox virus to scarified or punctured skin
4. Application of live vaccinia virus to scarified or punctured skin
5. Application of formalin-killed vaccinia virus to scarified or punctured skin
271. The biologic product that is commonly used for artificial active immunization
against tetanus is
1. Tetanus toxoid
2. Tetanus exotoxin
3. Tetanus endotoxin
4. Tetanus antitoxin
5. Heat-killed Clostridium tetani
272. Adjuvants are nonspecific, mildly irritating substances which are sometimes used
to
1. Enhance immune responses
2. Depress immune responses
3. Desensitize a patient to a given antigen
4. Remove antibodies from circulation
273. The development of most tumors appears to be inhibited by
a. Opsonin
b. Neutralizing antibodies
c. Cellular immunity
d. IgG
e. Lymphokines
1. A,e
2. B
3. C
4. B,d
5. C,e
274. Cross reacting tumor antigens are detected in all tumors induced by the same
1. Oncogenic virus
2. Chemical carcinogen
3. Immunosuppressive drug
4. Antibiotic
5. Both 1 and 2
275. The stimulation of a cellular immune response may be accomplished in cancer
patients by administration of
1. Methotrexate
2. BCG
3. Vincristine
4. 3-methylcholanthrene
5. None of the above
276. A high eosinophilic count in the peripheral blood is most suggestive of
1. Pulpitis
2. Trichinosis
3. Osteomyelitis
4. Pulmonary tuberculosis
 5. Histoplasmosis
277. Isolation of aerobic, spore forming rods from a boil on a patient’s neck is
suggestive of
1. Pseudomonas aeruginosa
2. Bacillus anthracis
3. Clostridium tetani
4. Streptococcus pyogenes
5. Staphylococcus aureus
278. A virus which persists in the oral tissues throughout the life of most individuals is
1. Rubella virus
2. Varicella virus
3. Herpes zoster virus
4. Herpes simplex virus
279. Rubeola, pertussis, poliomyelitis, and mumps have in common the fact that all are
1. Air borne diseases
2. Vector borne diseases
3. Characterized by a toxemia
4. Primarily diseases of infants
5. Prevented by active immunization
280. Negri bodies are histologic structures characteristically found in
1. Rabies
2. Herpes zoster
3. Rheumatic fever
4. Herpes simplex
5. Infectious mononucleosis
281. White adherent patches on buccal mucous membranes which consist of
pseudomycelium and chlamydospores and desquamated epithelium probably indicate an
infection by
1. Candida albicans
2. Cryptococcus neoformans
3. Histoplasma capsulatum
4. Coccidiodes immitis
282. Scarlet fever is an acute disease caused by
1. Toxin released by viridians streptococci
2. Salmonella typhosa with endotoxin release
 3. Group A streptococci releasing erythrogenic toxin
4. A mixture of streptococci and staphylococci with coagulase production
283. The microorganism which has been isolated most frequently from infected tooth
pulps is
1. Yeast
2. Actinomyces
3. Streptococci
4. Lactobacilli
5. Staphylococci
284. acute osteomyelitis may be caused by many microorganisms but statistically the
one most frequently encountered is
1. actinomyces
2. bacteriodes
3. streptococcus
4. staphylococcus
285. Oral protozoa are found to increase in the oral cavity when
1. Periodontitis become more advanced
2. Patients teeth are severely stained
3. Carious lesions increase
4. All of the above
286. A viral disease with oral manifestation
1. Anthrax
2. Diphtheria
3. Leishmaniasis
4. Herpangina
5. Candidiasis
287. Rheumatic fever is a disease which
1. Can result from a transient bacteremia by viridians streptococci
2. Is preceded by a group A streptococcal infection of the heart
3. Develops as a sequel to group A streptococci infections
4. Affects the glomeruli of the kidney
5. All of the above
288. The dermatomycoses are important fungal diseases because the
1. Infections tend to resist most forms of therapy
 2. Organisms are primarily found in the soil
3. Organisms frequently cause epidemics
4. Infections are often fatal
5. All of the above
289. A fungal disease which may be confused with tuberculosis because it produces
pulmonary calcifications is
1. Amoebiasis
2. Candidiasis
3. Blastomycosis
4. Actinomycosis
5. Histoplasmosis
290. Infectious hepatitis differs from serum hepatitis in that serum hepatitis
1. Has a shorter incubation period
2. Is more highly contagious
3. Is transmitted solely by the oral fecal route
4. Is associated with the presence of Australia antigen in the patient’s serum
291. A 6year old boy has minute white specks on the oral mucosa opposite the first
molars. A bluish to red ring surrounds these spots. He also has a “cold” and his eyes are
red and runny. There is a blotchy reddish rash behind his ears and on his face. This child
has
1. Eczema
2. Measles
3. Chickenpox
4. Scarlet fever
5. Rocky mountain spotted fever
292. Perleche is a disease most commonly cause by a
1. Virus
2. Fungal
3. Bacterium
4. Rickettsia
5. None of the above
293. The characteristic appearance of viral pneumonia is that of
1. Lobar pneumonia
2. Bronchopneumonia
3. Lobular pneumonia
 4. Interstitial pneumonia
294. Diphtheria, tetanus, scarlet fever and bacillary dysentery share as a common
factor of pathogenesis
1. Bacteremia
2. Pyemia
3. Septicemia
4. Toxemia
5. Viremia
295. The residual cardiac damage often produced by rheumatic fever predisposes the
patient to
1. Acute bacterial endocarditis
2. Acute glomerulonephritis
3. Acute hemolytic anemia
4. Erythroblastosis fetalis
5. Subacute bacterial endocarditis
296. The finding of gram negative diplococcic in the throat of an individual might
indicate that this person
1. Is carrying pneumococci
2. Is carrying nonpathogenic Nisseria
3. Has a Sarcina infection
4. Has a Streptococcus faecalis in the upper respiratory tract
297. Primary infection with the virus of herpes simplex
1. Is always followed by overt disease
2. Is more frequently inapparent than clinical
3. Results in a protective immunity to herpetic disease
4. Is more common in young adults than in children
298. Which of the ff microbial categories is present in the oral cavity in millions per
mm?
1. Candida species
2. Streptococcus species
3. Coliforms
4. Lactobacillus species
299. Certain staphylococci, Escherichia coli and Streptococci share as a property the
fact that they all
1. Are common in hospital infection
 2. Do not grow in nutrient agar
3. Fail to ferment glucose
4. Are gram positive
300. Positive Dick and Schick test are similar in that both are
1. Antigen-antibody reactions
2. Elicited by cellular injury due to toxin
3. Reactions to passively transferred antibody
4. Test-tube reactions
5. Delayed hypersensitivity
301. It is now generally accepted that actinomycosis is
1. A consequence of infection with an indigenous anaerobe
2. Largely limited to farmers and farm animals
3. Communicated from human to human
4. Transmitted by trauma with straws or other vegetable material carrying the
organisms
302. Neisseria catarrhalis is
1. The etiologic agent of gonorrhea
2. A normal inhabitant of the throat
3. Not capable of producing a positive oxidase test
4. The etiologic agent of meningococcemia
5. A small gram positive rod
303. Aphthous stomatitis resembles recurrent herpes in that
1. The lesions are similar
2. The antibody titer rises
3. Intranuclear inclusion bodies are present
4. Lifelong immunity results
5. The etiologic agent may be cultivated
304. Very painful vesicles may develop in the oral cavity in
1. Herpes simplex
2. Mumps
3. Primary syphilis
4. Lymphogranuloma venereum
305. Which of the ff genera of protozoa is found in the human mouth, intestine and
vagina?
 1. Chilomastix
2. Coccidiodes
3. Endolimax
4. Glandia
5. Trichomonas
306. The mycotic organism normally encountered in the oral flora appears in smear
and culture as
1. Penicillin
2. Aspergillus
3. Mucor
4. Candida
307. Hyaluronidase is an enzyme which
1. Forms the ground substance
2. Is most commonly produced by staphylococci
3. Acts as a spreading factor
4. Breaks down fibrin
5. Is inactive in the presence of microorganism
308. Protozoa most frequently found on human mucous membranes in the absence of
disease belong to which of the ff groups?
1. Amoebas and ciliates
2. Amoebas and flagellates
3. Ciliates and flagellates
4. Ciliates and sporozoa
5. Flagellates and sporozoa
309. Typhus fevers as a result of infection with agents classified as
1. Fungi
2. Viruses
3. Bacteria
4. Protozoa
5. Rickettsiae
310. A fungal disease with oral manifestation is
1. Anthrax
2. Gonorrhea
3. Leishmaniasis
 4. Candidiasis
5. Leprosy
311. Rubeola commonly produces an exanthema of the buccal mucosa designated as
1. Negri bodies
2. Fordyce’s spots
3. Paschen spots
4. Koplik’s spots
5. Guarnieri’s bodies
312. Gas gangrene is a pathologic condition usually caused by
1. Air contamination
2. Aerobic organisms
3. Anthrax bacillus
4. PPLO and PPO organisms
5. Clostridium species
313. Studies show that most infections of the dental pulp contain
1. Neisseria species
2. Candida albicans
3. Fusobacterium species
4. Lactobacillus species
5. Streptococcus species
314. The frequency of transient bacteremia has been shown to be highest in patients
with
1. Canker sores
2. Pulpectomies
3. Root canal therapy
4. Multiple extractions
5. Prophylactic odontomy
315. Lecithinases are produced by
1. Bacillus anthracis
2. Corynebacterium diptheriae
3. Mycobacterium tuberculosis
4. Salmonella schottmulleri
5. Clostridium perfringes
316. Herpangina results from an infection caused by
 1. Herpes zoster
2. Herpes simplex
3. Coxiella burnetti
4. Psittacosis virus
5. All of the above
317. Which of the ff are known to have a viral etiology?
a. Scarlet fever
b. Whooping cough
c. Mumps
d. Herpes simplex
e. Influenza
1. A,b,e
2. B,c
3. B,c,e
4. B,d,e
5. E
318. Which of the ff viruses are readily recovered and probably transmitted through the
saliva during the acute stages of disease?
1. Papilloma virus
2. Rubella
3. Cytomegalovirus
4. Herpes simplex virus
5. Both 3 and 4
319. The causative organisms for malaria belong to the genus
1. Vivax
2. Leishmania
3. Entamoeba
4. Plasmodium
5. Malarium
320. The microorganism that causes mucormycosis is closely related to the
1. Spirochetes
2. Viruses
3. Anaerobic-spore formers
4. Common bread mold
5. Etiologic agent of leishmaniasis
321. Which type of individual would probably be most susceptible to mucormycosis
1. Person manifesting active diabetes
2. Person with a general low level of resistance to microbial infection
3. Both 1 and 2
4. None of the above

322. In host cells infected with virus, inclusion bodies are found in
1. Nucleus only
2. Cytoplasm only
3. Cytoplasm in certain viral diseases and in nucleus in other viral diseases
4. Bacteria only
323. The production of collagenase in the periodontal tissue is characteristic of ____
and can be used to implicate this microorganism in the progression of periodontal disease
1. Veilonella alcalescens
2. Streptococcus mitis
3. Bacteroides melaninogenicus
4. Fusobacterium nucleatum
5. Peptostreptococcus
324. Ulceration of the gastrointestinal tract of man is most commonly associated with
1. Clostridium botulinum
2. Entamoeba histolytica
3. Haemophilus ducreyi
4. Salmonella gallinarum
5. Streptococcuss mitis
325. Rocky mountain spotted fever is caused by
1. Coxiella burnetti
2. Rickettsia conorii
3. Rickettsia rickettsii
4. Rickettsia tsutsugamushi
326. A serious oral manifestation of advanced leishmaniasis is
1. Cancrum oris
2. Kala-azar
3. Cold sore
4. Negri bodies
327. The most common form of malaria is
 1. Benign tertian malaria
2. Quartan malaria
3. Malignant tertian malaria
4. Ovale malaria
328. Which of the ff is not a common symptom of malaria?
1. Chills
2. Sneezing
3. Fever
4. Anemia
329. Entamoeba gingivalis is commonly found in the oral-pharyngeal cavity in
1. Soft calculus
2. Chronic suppurative periodontal lesions
3. Gingival pockets
4. Diseased tonsils
5. All of the above
330. A positive Australia antigen test indicated infection or exposure to
1. Cytomegalovirus
2. Hepatitis A virus
3. Hepatitis B virus
4. All of the above
5. Both 1 and 2
331. Some anaerobic soil organisms cause disease in man because of their ability to
form
1. Exotoxins
2. Endotoxins
3. Hemolysin
4. Sulfatase
5. Hyaluronidase
332. A bacterial disease with oral manifestations is
1. Measles
2. Diphtheria
3. Candidiasis
4. Leishmaniasis
5. Herpetic stomatitis
333. Streptococcal infection of the uterus following delivery is known as
1. Yaws
2. Dengue
3. Scarlet fever
4. Puerperal fever
5. Relapsing fever
334. Enterotoxin responsible for food intoxication is most often produced by
1. Enterococci
2. Staphylococcus aureus
3. Diplococcus pneumonia
4. Beta-hemolytic streptococci
335. Rheumatic fever is a disease which may leave the heart seriously damaged
because of
1. Primary infection of the heart valves with group A streptococci
2. Damage to the heart valves thought to be a result of hypersensitivity to infection
with group A streptococci
3. Damage to the heart valves thought to be a result of hypersensitivity to infection
with hemolytic staphylococci
4. Primary infection of the heart valves with alpha-hemolytic streptococci
336. Which of the ff resembles tuberculosis in its primary acute form?
1. Candidiasis
2. Histoplasmosis
3. Sporotrichosis
4. Geotrichosis
337. Pathogenic organisms may cause disease because of
1. Toxicity
2. Invasiveness
3. Antiphagocytic bacterial factors
4. All of the above
338. As a result of dental prophylaxis, microorganisms from about the teeth gent into
the blood stream. This condition is an example of
1. Pyemia
2. Bacteremia
3. Septicemia
4. Focal infection
339. The most common causative bacterium in subacute bacterial endocarditis is found
in group of
1. Pneumococci
2. Virulent staphylococci
3. Beta-hemolytic streptococci
4. Alpha-hemolytic streptococci
340. A disease with oropharyngeal lesions caused by coxsackie virus is called
1. Cat-scratch fever
2. Herpangina
3. Infectious mononucleosis
4. Salivary gland disease
5. Vesicular stomatitis
341. A serious acute infection usually involving the neck and throat which sometimes
occurs as a result of the spread of infection from a periapical tissue abscess along the
facial planes of the neck is known as
1. Impetigo
2. Herpangina
3. Candidiasis
4. Ludwig’s angina
5. Epidemic parotitis
342. Which of the ff is true of hepatitis B and tuberculosis?
1. Both are easily detected in dental patient
2. The causative organisms appear to be sensitive to most disinfectants
3. Both have long incubation periods during which they may be contagious
4. Undiagnosed carriers present no problem of cross infection to the dentist and
patients
5. Neither can produce a debilitating infection with present therapeutic methods
343. Varicella (chickenpox) virus belongs in which of the ff groups?
1. Herpes virus
2. Poxvirus
3. Papovavirus
4. Adenovirus
5. Coxsackie virus
344. Chicken pox is produced by the varicella virus, which is the same agent, or is
related to the agent, causing
 1. Hepatitis
2. Mumps
3. Herpes zoster
4. Rabies
5. None of the above
345. The most common primary or initial infection with herpes simplex virus is
1. Keratitis
2. Conjunctivitis
3. Hepetic whitlow
4. Acute herpetic gingivostomatitis
5. Herpangina
346. Which of the ff genera generally contain species which may live in the oral cavity
without apparently causing disease?
a. Entamoeba
b. Plasmodium
c. Giardia
d. Trypsanoma
e. Leishmania
f. Balantidium
g. Trichomonas
1. A,b
2. C,d
3. A,e
4. B,f
5. A,g
347. The usual incubation period for hepatitis B virus infection is
1. 1-2 days
2. 1-2 weeks
3. 1-6 months
4. 1 year
5. 5 years

348. Which of the ff is generally associated with greater mortality and a longer clinical
course in humans?
1. Hepatitis A
2. Hepatitis B
 3. Herpes simplex virus type 1
4. Initial varicella infection
5. Rubeola infection
349. Intranuclear inclusions calle ______ are detected, during the course of herpes
simplex virus clinical infection
1. Guerneri’s bodies
2. Negri bodies
3. Lipschutz bodies
4. Paschen bodies
5. Bacteriophages
350. Which one of the ff parasites is most apt to be found coiled and encysted in
skeletal muscle?
1. Trichinella spiralis
2. Strongyloides stercoralis
3. Enterobius vernicularis
4. Ascaris lumbricoides
5. Schistosoma haemotobium
351. Which of the ff lesions always appears at the site of entry of the etiologic agent?
1. Gumma
2. Hard chancre
3. Mucous patches
4. All of the above
352. Dimorphism of a systemic disease-producing fungus is common, whereas a
fungus produced gingivitis is infrequent. A fungus having both of these capabilities is
1. Blastomyces
2. Histoplasma
3. Coccidiodes
4. Cryptococcus
353. The common venereal disease of the chlamydiae group is
1. Lymphogranuloma venereum
2. Pssitacosis
3. Trachoma
4. Yaws
354. Trachoma is best treated with
1. Topically applied tetracycline and orally administered sulfonamides
 2. Penicillin
3. Tetracycline administered orally
4. Sulfonamides applied topically
355. Psittacosis occurs primarily in parrots, parakeets, cockatoos,etc. in man it may
take the form of a primary atypical pneumonia. The agent is named
1. Eaton agent
2. Ornithosis agent
3. Mycoplasma pneumoniae
4. Trachoma
356. An example of fungus that causes a deep (systemic) mycosis and produces
arthrospores is
1. Aspergillus
2. Coccidiodes
3. Cryptococcus
4. Candida
357. Superficial mycoses are also called
1. Dimorphisms
2. Dermatophytoses
3. Systemic mycoses
4. Actinomycoses
358. Which of the ff genera of fungus diseases is not readily transmitted from human
to human?
1. Epidermophyton
2. Microsporum
3. Histoplasma
4. Trichophyton
359. The majority of epidemic ringworm of the scalp in humans which can be traced to
the use of common barber shop clippers, transger of infected hairs on theater seats, or
person-to-person contact is due to
1. Microsporum audouini
2. Microsporum canis
3. Miscrosporum gypseum
4. Trichophyton mentagrophytes
360. The Crede procedure is associated with protection from
1. Francisella tularensis
2. Ludwig’s angina etiologic agent
3. Spirochetes
4. The etiologic agent in gonorrhea.