A Microbiology Knowledge Review Quiz

21 Questions | Total Attempts: 12

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Microbiology Quizzes & Trivia

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Questions and Answers
  • 1. 
    Assume the following cells have no plasmids other than those mentioned. Which cell type would contain two molecules of DNA?
    • A. 

      F+ 

    • B. 

      F-

    • C. 

      Hfr

  • 2. 
    Assume the cells whose genotype is listed have no other plasmids than those indicated by the indicated genotype. Which bacterial is most likely to transfer chromosomal genes in linear order?
    • A. 

      F+

    • B. 

      F-

    • C. 

      Hfr

    • D. 

      Option 4

  • 3. 
    What bacterial gene transfer process is most sensitive to extracellular nucle-ases?
    • A. 

      Conjugation

    • B. 

      Generalized transduction

    • C. 

      Homologous recombination

    • D. 

      Site-specific recombination

    • E. 

      Specialized transduction

    • F. 

      Transformation

  • 4. 
    Following specialized transduction, if any of the bacterial genes transferred in are to be stabilized, what process must occur?
    • A. 

      Conjugation

    • B. 

      Generalized transduction

    • C. 

      Homologous recombination

    • D. 

      Site-specific recombination

    • E. 

      Specialized transduction

    • F. 

      Transformation

  • 5. 
    The ability of a cell to bind DNA to its surface and import it is required for which genetic process?
    • A. 

      Conjugation

    • B. 

      Generalized transduction

    • C. 

      Homologous recombination

    • D. 

      Site-specific recombination

    • E. 

      Specialized transduction

    • F. 

      Transformation

  • 6. 
    The process by which bacterial or plasmid DNA  may be mistakenly incor-porated (during assembly) into one phage being produced by the lytic life cycle and then DNA - transferred to another bacterial cell which may acquire some new genetic traits is called
    • A. 

      Conjugation

    • B. 

      Generalized transduction

    • C. 

      Homologous recombination

    • D. 

      Site-specific recombination

    • E. 

      Specialized transduction

    • F. 

      Transformation

  • 7. 
    Lysogenic conversion
    • A. 

      Is a change in pathogenicity due to the presence of a prophage

    • B. 

      Is the induction of a prophage to its virulent state

    • C. 

      Is the conversion of a virulent phage into a temperate phage

    • D. 

      Refers to the incorporation of a prophage into the chromosome

    • E. 

      Is the immunity that a prophage confers on a bacterium

  • 8. 
    Which of the following events is most likely due to bacterial transformation?
    • A. 

      A formerly non- toxigenic stran of Corynebacterium dephtheriae beocmes toxigenic

    • B. 

      A non-encapsulated strain of streptococcus pneumoniae accquires a gene for capsule formation from the extract of an encapsulated strain

    • C. 

      A strain of Neisseria gonorrhoeae starts producing a plasmid-encoded β-lactamase similar to that another gram-negative strain

    • D. 

      A gene for gentamicin resistance from an Escherichia coli chromosome appears in the genome of a bacteriophage that has infected it

  • 9. 
    A 12-year old girl experienced a GAS pharyngitis and within 3 weeks had chest pain and developed new murmurs of mitral regurgitation. Which of yhe following statement best typifies the disease she experienced?
    • A. 

      It is a complication of group A streptococcal skin disease but usually not of pharyngitis

    • B. 

      It is characterized by inflammatory lesions that may involve the heart, joints, subcutaneous tissues, and CNS

    • C. 

      It is very common in developing countries but extremely rare and decreasing in incidence in the United States

    • D. 

      Prophylaxis with benzathine penicillin is of little value

    • E. 

      The pathogenesis is related to the similary between a staphylococcal antigen and a human cardiac antigen

  • 10. 
    A young child developed staphylococcal scaleded syndrome. Which one of the following toxins is most likely responsible for this syndrome?
    • A. 

      Alpha toxin

    • B. 

      Erythrogenic toxin

    • C. 

      Exfoliative toxin

    • D. 

      Staphylococcal enterotoxins A through F

    • E. 

      Toxic shock syndrome toxin (TSST)

  • 11. 
     43-year-old man who recently returned from a trip to rural Peru presents with severe watery diarrhea, vomiting, and dehydration. He also has marked leg cramps and has lots 8lb since his return form the trip. fecal culture is positive for V.cholerae. How does this bacterium exert its effect?
    • A. 

      Activation of enterokinase on the brush border of epithelial cells

    • B. 

       activation of cholecystokinin effects on pancreatic secretion

    • C. 

      Closure of chloride channels in the enterocyte cell membrane

    • D. 

      Inhibition of cyclic AMP in the enterocytes.

    • E. 

      ADP-ribosylation of GS of the GPT-binding protein in enterocytes

  • 12. 
    A 3-year-old girl from a family that does not believe in immunization to the emergency room with a sore throat, fever, malaise, and difficulty breathing. A gray membrane covering the pharynx is observed on physical emamination. Which of the following best describes C.diptheriae, the etiologic agent?
    • A. 

      It produces at least one protein toxin consiting of two subunits, A and B, that cause severe spasmodic cough, usually in children

    • B. 

      It produces a toxin that blocks protein synthesis in an infected cell and carries a lytic bacteriophage that produces the genetic information for toxin production

    • C. 

      It secretes an erythrogenic toxin that causes the characteristic signs of scarlet fever

    • D. 

      It secretes an exotoxin that has been called "verotoxin" and "Shiga-like toxin"; infection is mediated by specific attachment to mucosal membranes

    • E. 

      It requires cysteine for growth

  • 13. 
    A 4-year-old girl awakens at midnight complaining of a sore throat and headache, and she has a fever of 1010F. Physical examination reveals an erythematous throat. A rapid strep test is positive. A throat swab is sent to the labotary for further testing. Which of the following best characterizes S pyogenes as the presumed etiologic agent?
    • A. 

      It produces at least one protein toxin consisting of two subunits, A and B, that cause severe spasmodic cough. usually in children

    • B. 

      It produces a toxin that blocks protein synsthesis in an infected cell and carries a lytic bacterophage that produces the genetic information for toxin production

    • C. 

      It secretes an exotoxin that has been called "verotoxin" and "Shiga-like toxin"; infection is mediated by specific attachment to mucosal membranes

    • D. 

      It secretes an erythrogenic toxin that causes the  characteristic signs of scarlet fever

    • E. 

      It has capsules of polyglutamic acid, which is toxic when ịnected into rabbits

  • 14. 
    A severely burned firefighter develops a rapidly disseminating bacterial infection while hospitalized. "Green pus" is noted in the burned tissue, and cultures of both the tissue and blood yield small, oxidase-positive, gram-negative rods. Which of the following statements about this organism is correct?
    • A. 

      Endotoxin is the only virulence factor known to be produced by these bacteria

    • B. 

      Humans are the only known reservoir hosts for these bacteria

    • C. 

      The bacteria are difficult to culture because they have numerous growth requirements

    • D. 

      These are among the most antibiotic resistant of all clinically relevant bacteria

    • E. 

      These highly motile bacteria can "swarm" over the surface of culture media

  • 15. 
    Vibrio cholerae is worldwide in distribution and continues to expand as water sources become polluted. Which of the following best describe this organism?
    • A. 

      Cause of gastroenteritis, reservoir in birds and mammals, optimal growth at 107.60F (420C)

    • B. 

      Human pathogen, halophilic, lactose-positive, sucrose-negative, causes gastrointestinal diseases primarily from ingestion of under-cooked seafood

    • C. 

      Human pathogen, halophilic, lactose-positive, produces heat-labile, extracellular toxin, wound infections

    • D. 

      Organism susceptible to acid; not an invasive organism

    • E. 

      Urease-positive, cause of fetal distress in cattle

  • 16. 
    A healthy 45-year-old female hat root canal treatment about 3 weeks ago. She not presents with a new heart murmur, fever, painful skin nodules, and abdominal pain, with an abnormal liver function test. Which of the following organisms would most likely cause endocarditis and be implicated in dental caries or root canal infections?
    • A. 

      α-hemolytic strepticocci

    • B. 

      Fragilis

    • C. 

      E.coli

    • D. 

      Lactobacillus

    • E. 

      S.epidermidis

  • 17. 
    Chlamydiae are small, gram-negative rods once thought to be viruses. Which of the following best characterizes chlamydiae as distinct from viruses?
    • A. 

      Cannot visualize with light microscope

    • B. 

      Independent synthesis of proteins

    • C. 

      Intracellular reproduction

    • D. 

      Susceptibility to antimicrobial agents (penicillins)

    • E. 

      Synthesis of ATP

  • 18. 
    S.pneumoniae cause significant morbidity and mortality due to capsular virulence factors. These capsules (55 antigenic types) are characterized by which of the following?
    • A. 

      γ-Glutamyl polypeptide

    • B. 

      Hyaluronic acid

    • C. 

      Outer-membrane proteins

    • D. 

      Repeating polysaccharide capsule of glucose and glucuronic acid

    • E. 

      Sialic acid polymers

  • 19. 
    A 6-year-old girl presents to her pediatrician with fever, headache, and a sore throat. She has swollen tender cervical lymph nodes, and her oropharynx is red  with gray-white exudate covering both her tonsils. A rapid strep test of her throat swab is possitive, and the culture subsequently grows β-hemolytic Streptococcus. Which of the following antibiotic therapies is most appropriate for treating this patient?
    • A. 

      Ampicillin

    • B. 

      Ceftriaxone

    • C. 

      Erythromycin

    • D. 

      Penicillin

    • E. 

      Vancomycin

  • 20. 
    Streptococcus mutans is best described by which of the following statements?
    • A. 

      An anaerotic, filamentous bacterium that often causes cervicofacial osteomyelitis

    • B. 

      A β-hemolytic organism that causes a diffuse, rapidly spreading cellulitis

    • C. 

      A facultative anaerobe that is highly cariogenic and sticks to teeth by synthesis of a dextran

    • D. 

      A facultative anaerobe that often inhabits the buccal mucosa early in a neonate's life and can cause bacterial andocarditis

    • E. 

      A Facultative anaerobic, rod-shaped bacterium that sticks to teeth and is cariogenic

  • 21. 
    A 3-year-old girl, with no history of vaccination, is brought to the hospital with a sore throat, fever, malaise, and difficulty breathing. physical examination reveals a gray membrane covering the pharynx. Growth of the etiolgic agent on  cysteine-tellurite agar forms gray to black colonies with a brown halo. The major virulence factor of this organism is only produced by those strains that will most likely have which of the following characteristics?
    • A. 

      Encapsulated

    • B. 

      Glucose fermenters

    • C. 

      Lysogenic for β-prophage

    • D. 

      Of the mitis strain

    • E. 

      Sucrose fermenters