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Which of the following antibiotics is recommended for use against gram-negative bacteria? 1) _______
A) bacitracin
B) polyenes
C) polymyxin
D) penicillin
E) cephalosporin
|
c
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Penicillin was considered a "miracle drug" for all of the following reasons EXCEPT 2) _______
A) it was the first antibiotic.
B) it inhibits gram-positive cell wall synthesis.
C) it does not affect eukaryotic cells.
D) it kills bacteria.
E) it has selective toxicity.
|
a
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Which of the following does NOT constitute an advantage of using two antibiotics together? 3) _______
A) It allows treatment to be provided prior to diagnosis.
B) It can prevent drug resistance.
C) It lessens the toxicity of individual drugs.
D) Two are always twice as effective as one.
E) All of these are advantages of using two antibiotics together.
|
D
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Drug resistance occurs 4) _______
A)when antibiotics are taken after the symptoms disappear.
B) because bacteria are normal microbiota.
C) against antibiotics and not against synthetic chemotherapeutic agents.
D) when antibiotics are used indiscriminately.
E) All of the answers are correct.
|
D
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To date, most of our natural antibiotics have been found to be produced by members of what genus? 5) _______
A) Streptomyces
B) Penicillium
C) Paenibacillus
D) Cephalosporium
E) Bacillus
|
A
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In the presence of penicillin, a cell dies because 6) _______
A) it undergoes lysis.
B) its contents leak out.
C) it lacks a cell wall.
D) it lacks a cell membrane.
E) it plasmolyzes.
|
A
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Mebendazole is used to treat cestode infections. It interferes with microtubule formation; therefore, it would NOT affect 7) _______
A) protozoa.
B) bacteria.
C) helminths.
D) human cells.
E) fungi.
|
B
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Which of the following would be selective against the tubercle bacillus? 8) _______
A) vancomycin inhibits peptidoglycan synthesis
B) ethambutol inhibits mycolic acid synthesis
C) bacitracin inhibits peptidoglycan synthesis
D) streptomycin inhibits protein synthesis
E) streptogramin inhibits protein synthesis
|
B
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Which of the following antimicrobial agents is recommended for use against fungal infections? 9) _______
A) bacitracin
B) polymyxin
C) cephalosporin
D) penicillin
E) amphotericin B
|
E
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Which of the following is mismatched? 10) ______
A) Florey and Chain – identification of Penicillium as the producer of penicillin
B) Kirby and Bauer – disc-diffusion method
C) Ehrlich – "magic bullet" theory
D) Fleming – identification of penicillin
E) None of these is mismatched.
|
A
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Protozoan and helminthic diseases are difficult to treat because 11) ______
A) they do not have ribosomes.
B) they replicate inside human cells.
C) they have more genes than bacteria.
D) their cells are structurally and functionally similar to human cells.
E) they do not reproduce
|
D
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The structures of the influenza drug Tamiflu and sialic acid, the substrate for influenza virus’s neuramidase, are shown in Figure 20.4. What is the method of action of Tamiflu? 12) ______
A) inhibits plasma membrane synthesis
B) inhibits synthesis of neuramidase
C) competitive inhibition
D) inhibits cell wall synthesis
E) prevents synthesis of virus spikes
|
C
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The structures of the influenza drug Tamiflu and sialic acid, the substrate for influenza virus’s neuramidase, are shown in Figure 20.4. What is the method of action of Tamiflu? 12) ______
A) inhibits plasma membrane synthesis
B) inhibits synthesis of neuramidase
C) competitive inhibition
D) inhibits cell wall synthesis
E) prevents synthesis of virus spikes
|
C
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Which of the following methods of action would be bacteriostatic? 14) ______
A) inhibition of protein synthesis
B) inhibition of cell wall synthesis
C) injury to plasma membrane
D) competitive inhibition with DNA gyrase
E) competitive inhibition with folic acid synthesis
|
A
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In Table 20.2, the most effective antibiotic tested was 15) ______
A) A.
B) B.
C) C.
D) D.
E) The answer cannot be determined based on the information provided.
|
D
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The antibiotic actinomycin D binds between adjacent G-C pairs, thus interfering with 16) ______
A) transcription.
B) peptide bond formation.
C) plasma membrane function.
D) cellular respiration.
E) translation.
|
A
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The data in Table 20.3 show that these bacteria 17) ______
A) were resistant to 1.0 μg/ml at the start of the experiment.
B) are pathogenic.
C) were killed by 0.5 μg/ml of antibiotic X.
D) were killed by 0.125 μg/ml of antibiotic X.
E) developed resistance to antibiotics.
|
E
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Which of the following antimicrobial agents has the fewest side effects? 18) ______
A) streptomycin
B) chloramphenicol
C) penicillin
D) tetracycline
E) erythromycin
|
C
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Antimicrobial peptides work by 19) ______
A) hydrolyzing peptidoglycan.
B) inhibiting cell-wall synthesis.
C) disrupting the plasma membrane.
D) complementary base pairing with DNA.
E) inhibiting protein synthesis.
|
C
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Which of the following statements is FALSE? 20) ______
A) Azoles inhibit plasma membrane synthesis.
B) Acyclovir inhibits DNA synthesis.
C) Fluoroquinolone inhibits DNA synthesis.
D) Amantadine inhibits the release of viral nucleic acid.
E) Interferon inhibits glycolysis.
|
E
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Which of the following antibiotics are used to treat fungal infections?
1. aminoglycosides
2. cephalosporins
3. griseofulvin
4. polyenes
5. bacitracin 21) ______
A) 1, 2, and 3
B) 3 and 4
C) 3, 4, and 5
D) 4 and 5
E) All of these antibiotics are used to treat fungal infections.
|
B
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Which of the following statements about drug resistance is FALSE? 22) ______
A) It may be due to increased uptake of a drug.
B) It may be transferred from one bacterium to another during conjugation.
C) It may be carried on a plasmid.
D) It is found only in gram-negative bacteria.
E) It may be due to enzymes that degrade some antibiotics.
|
D
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Which of the following organisms would MOST likely be sensitive to natural penicillin? 23) ______
A) Penicillium
B) penicillinase-producing Neisseria gonorrhoeae
C) helminths
D) Mycoplasma
E) Streptococcus pyogenes
|
E
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Which of the following drugs does NOT act by competitive inhibition? 24) ______
A) streptomycin
B) sulfonamide
C) trimethoprim
D) ethambutol
E) isoniazid
|
A
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Which of the following does NOT affect eukaryotic cells? 25) ______
A) antihelminthic drugs
B) nucleotide analogs
C) antiprotozoan drugs
D) antifungal drugs
E) semisynthetic penicillins
|
E
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Which of the following antibiotics is NOT bactericidal? 26) ______
A) cephalosporins
B) polyenes
C) penicillin
D) rifampins
E) aminoglycosides
|
B
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Which of the following antibiotics causes misreading of mRNA? 27) ______
A) chloramphenicol inhibits peptide bonds at 50S subunit
B) oxazolidinone prevents formation of 70S ribosome
C) tetracyclines bind with 30S subunit
D) aminoglycoside changes shape of 30S units
E) streptogamin prevents release of peptide from 70S ribosome
|
D
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The substrate for transpeptidase used to synthesize peptidoglycan is shown in Figure 20.3. Which of the drugs shown would inhibit peptidoglycan synthesis? 28) ______
A) a B) b C) c D) d E) e
|
D
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n Table 20.2, the antibiotic that exhibited bactericidal action was 29) ______
A) A.
B) B.
C) C.
D) D.
E) The answer cannot be determined based on the information provided.
|
E
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Which one of the following does NOT belong with the others? 30) ______
A) bacitracin
B) monobactam
C) cephalosporin
D) streptomycin
E) penicillin
|
D
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Most of the available antimicrobial agents are effective against 31) ______
A) fungi.
B) protozoa.
C) viruses.
D) bacteria.
E) All of the answers are correct.
|
D
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Niclosamide prevents ATP generation in mitochondria. You would expect this drug to be effective against 32) ______
A) gram-positive bacteria.
B) viruses.
C) helminths.
D) Mycobacterium tuberculosis.
E) gram-negative bacteria.
|
C
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In Table 20.1, the minimal bactericidal concentration of antibiotic X is 33) ______
A) 15 μg/ml.
B) 25 μg/ml.
C) 10 μg/ml.
D) 2 μg/ml.
E) The answer cannot be determined based on the information provided.
|
A
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In Table 20.1, the minimal inhibitory concentration of antibiotic X is 34) ______
A) 2 μg/ml.
B) 10 μg/ml.
C) 25 μg/ml.
D) 15 μg/ml.
E) The answer cannot be determined based on the information provided.
|
B
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Use of antibiotics in animal feed leads to antibiotic-resistant bacteria because 35) ______
A) the antibiotics cause new mutations to occur in the surviving bacteria, which results in resistance to antibiotics.
B) bacteria from other animals replace those killed by the antibiotics.
C) the antibiotics kill susceptible bacteria, but the few that are naturally resistant live and reproduce, and their progeny repopulate the host animal.
D) the antibiotics persist in soil and water.
E) the few surviving bacteria that are affected by the antibiotics develop immunity to the antibiotics, which they pass on to their progeny.
|
C
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The antimicrobial drugs with the broadest spectrum of activity are 36) ______
A) chloramphenicol.
B) aminoglycosides.
C) penicillin G.
D) macrolides.
E) tetracyclines.
|
E
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Which of the following antibiotics does NOT interfere with cell wall synthesis? 37) ______
A) macrolides
B) semisynthetic penicillins
C) cephalosporins
D) vancomycin
E) natural penicillins
|
A
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Which of the following statements about drugs that competitively inhibit DNA polymerase or RNA polymerase is FALSE? 38) ______
A) They cause cellular plasmolysis.
B) They can affect host cell DNA.
C) They cause mutations.
D) They are used against viral infections.
E) They interfere with protein synthesis.
|
A
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More than half of our antibiotics are 39) ______
A) produced by fungi.
B) produced by bacteria.
C) produced by eukaryotic organisms.
D) produced by Fleming.
E) synthesized in laboratories.
|
B
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The antibiotic cycloheximide binds to the 60S subunit of the ribosome, as shown in Figure 20.2. The effect is to 40) ______
A) prevent transcription in prokaryotes.
B) prevent ribosome formation in bacteria.
C) prevent mRNAribosome binding in eukaryotes.
D) prevent peptide bond formation in prokaryotes.
E) prevent polypeptide elongation in eukaryotes.
|
D
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Lamisil is an allylamine used to treat dermatomycoses. Lamisil’s method of action is similar to that of 41) ______
A) bacitracin.
B) azole antibiotics.
C) polymyxin B.
D) griseofulvin.
E) echinocandins.
|
B
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|
In Table 20.2, which antibiotic would be most useful for treating a Salmonella infection? 42) ______
A) A
B) B
C) C
D) D
E) The answer cannot be determined based on the information provided.
|
E
|
|
Which compound would be the most useful to treat candidiasis? 43) ______
A) thymine
B) guanine
C) flucytosine
D) penicillin
E) uracil
|
C
|
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In what way are semisynthetic penicillins and natural penicillins alike? 44) ______
A) Both are based on β-lactam.
B) Both are bactericidal.
C) Both are broad spectrum.
D) Both are resistant to stomach acids.
E) Both are resistant to penicillinase.
|
A
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The antibiotic tetracycline binds to the 30S subunit of the ribosome, as shown in Figure 20.1. The effect is to 45) ______
A) prevent peptide bond formation.
B) stop the ribosome from moving along the mRNA.
C) prevent transcription.
D) interfere with the attachment of the tRNA to mRNA-ribosome complex.
E) prevent attachment of DNA.
|
D
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Both trimethoprim and sulfamethoxazole inhibit reactions along the same metabolic pathway.
|
T
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|
Antiviral drugs target viral processes that occur during viral infection.
|
T
|
|
Phage therapy has been used in the past as an antiviral treatment.
|
F
|
|
Penicillin and streptomycin are commonly used in syngerism because they display the same mode of action.
|
F
|
|
Only microbes produce antimicrobial peptides.
|
F
|
|
Undergrowth of fungi after antibiotic use is commonly referred to as a superinfection.
|
F
|
|
Due to its target, rifamycins can be effective over a broad spectrum.
|
T
|
|
PABA serves as the competitive inhibitor in the action of sulfanilamides.
|
F
|
|
Community-acquired MRSA is typically more virulent than health care-associated MRSA.
|
T
|
|
An antibiotic that attacks the LPS layer would be expected to have a narrow spectrum of activity.
|
T
|
|
In Table 20.2, the most effective antibiotic tested was 15) ______
A) A.
B) B.
C) C.
D) D.
E) The answer cannot be determined based on the information provided.
|
…
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