Question 1

Which of the following would be selective against the tubercle bacillus?

Accepted Answer

A)   Streptomycin - inhibits protein synthesis
B)   Vancomycin - inhibits peptidoglycan synthesis
C)   Streptogramin - inhibits protein synthesis
D)   Ethambutol - inhibits mycolic acid synthesis
E)   Bacitracin - inhibits peptidoglycan synthesisF) A) and C)
G) A) and D)

Question 2

Figure 20.5
 
-If the compound shown in Figure 20.5 is the substrate for a particular enzyme, which of the drugs would be the most effective competitive inhibitor?

Accepted Answer

A)   a
B)   b
C)   c
D)   d
E)   None of the above.F) B) and D)
G) A) and E)

Question 3

Protozoan and helminthic diseases are difficult to treat because

Accepted Answer

A)   Their cells are structurally and functionally similar to human cells.
B)   They replicate inside human cells.
C)   They don't reproduce.
D)   They don't have ribosomes.
E)   None of the above.F) B) and D)
G) A) and C)

Question 4

Table 20.1
The following data were obtained from a broth dilution test.   Growth in  Concentration of Antibiotic X Growth  Subculture 2μg/ml++10μg/ml−+15μg/ml−−25μg/ml−−\begin{array}{c}&&	ext { Growth in }\	ext { Concentration of Antibiotic } X&	ext { Growth }&	ext { Subculture }\\hline2 \mu \mathrm{g} / \mathrm{ml}&+&+ \10 \mu \mathrm{g} / \mathrm{ml}&-&+ \15 \mu \mathrm{g} / \mathrm{ml} &-&-\25 \mu \mathrm{g} / \mathrm{ml}&-&-\end{array} Concentration of Antibiotic X2μg/ml10μg/ml15μg/ml25μg/ml​ Growth +−−−​ Growth in  Subculture ++−−​​ 
-In Table 20.1, the minimal bactericidal concentration of antibiotic X is

Accepted Answer

A)   15 µg/ml.
B)   25 µg/ml.
C)   2 µg/ml.
D)   10 µg/ml.
E)   Can't tell. F) B) and C)
G) C) and D) A

Question 5

Which one of the following does not belong with the others?

Accepted Answer

A)   Bacitracin
B)   Cephalosporin
C)   Monobactam
D)   Streptomycin
E)   PenicillinF) A) and C)
G) A) and B)

Question 6

Which of the following antibiotics is not bactericidal?

Accepted Answer

A)   Cephalosporins
B)   Aminoglycosides
C)   Penicillin
D)   Polyenes
E)   RifampinsF) D) and E)
G) C) and E)

Question 7

Figure 20.4
 
-The antibiotic streptomycin binds to the 30S subunit of the ribosome as shown in Figure 20.4. The effect is to

Accepted Answer

A)   Prevent binding of tRNA in eukaryotes.
B)   Cause misreading of mRNA in 70S ribosomes.
C)   Prevent peptide bond formation in prokaryotes.
D)   Prevent polypeptide elongation in eukaryotes.
E)   None of the above.F) B) and C)
G) A) and D)

Question 8

Use of antibiotics in animal feed leads to antibiotic- resistant bacteria because

Accepted Answer

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 few surviving bacteria that are affected by the antibiotics develop immunity to the antibiotics, which they pass on to their progeny.
E)   The antibiotics persist in soil and water.F) A) and E)
G) B) and D)

Question 9

All of the following statements about drug resistance are true except

Accepted Answer

A)   It may be due to enzymes that degrade some antibiotics.
B)   It may be due to increased uptake of a drug.
C)   It may be carried on a plasmid.
D)   It is found only in gram- negative bacteria.
E)   It may be transferred from one bacterium to another during conjugation.F) B) and D)
G) C) and D)

Question 10

Which of the following antibiotics causes misreading of mRNA?

Accepted Answer

A)   Chloramphenicol - inhibits peptide bonds at 50S subunit
B)   Streptogamin - prevents release of peptide from 70S ribosome
C)   Tetracyclines - bind with 30S subunit
D)   Aminoglycoside - changes shape of 30S units
E)   Oxazolidinone - prevents formation of 70S ribosomeF) B) and E)
G) A) and E)

Question 11

Drug resistance occurs

Accepted Answer

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 above.F) B) and D)
G) A) and C)

Question 12

Which of the following is not bactericidal?

Accepted Answer

A)   Natural penicillin
B)   Streptomycin
C)   Bacitracin
D)   Tetracycline
E)   Semisynthetic penicillinF) None of the above
G) D) and E) D

Question 13

Which of the following methods of action would be bacteriostatic?

Accepted Answer

A)   Injury to plasma membrane
B)   Competitive inhibition with folic acid synthesis
C)   Inhibition of RNA synthesis
D)   Inhibition of cell wall synthesis
E)   None of the aboveF) A) and B)
G) A) and C)

Question 14

Table 20.3
The following data were obtained from a broth dilution test:

Concentration of Antibiotic X Growth 2.0μg/ml−1.0μg/ml−0.5μg/ml−0.25μg/ml+0.125μg/ml+0+\begin{array}{ll}	ext { Concentration of Antibiotic } X&	ext { Growth }\\hline2.0 \mu \mathrm{g} / \mathrm{ml} & - \1.0 \mu \mathrm{g} / \mathrm{ml} & - \0.5 \mu \mathrm{g} / \mathrm{ml} & - \0.25 \mu \mathrm{g} / \mathrm{ml} & + \0.125 \mu \mathrm{g} / \mathrm{ml} & + \0 & +\end{array} Concentration of Antibiotic X2.0μg/ml1.0μg/ml0.5μg/ml0.25μg/ml0.125μg/ml0​ Growth −−−+++​​  
Bacteria from the 0.25 µg/ml tube were transferred to new growth media containing antibiotic X with the following results:

Concentration of Antibiotic ‾X Growth‾2.0μg/ml1.0μg/ml−0.5μg/ml+0.25μg/ml+\begin{array}{ll} \underline{	ext { Concentration of Antibiotic }} X& \underline{	ext { Growth} }\2.0 \mu \mathrm{g} / \mathrm{ml} \1.0 \mu \mathrm{g} / \mathrm{ml} & - \0.5 \mu \mathrm{g} / \mathrm{ml} & + \0.25 \mu \mathrm{g} / \mathrm{ml} & + \\end{array} Concentration of Antibiotic ​X2.0μg/ml1.0μg/ml0.5μg/ml0.25μg/ml​ Growth​−++​ 
-The data in Table 20.3 show that these bacteria

Accepted Answer

A)   Developed resistance to antibiotics.
B)   Can be subcultured.
C)   Were killed by 0.5 µg/ml of antibiotic X.
D)   Were killed by 0.125 µg/ml of antibiotic X.
E)   Were resistant to 1.0 µg/ml at the start of the experiment. F) A) and E)
G) None of the above

Question 15

Semisynthetic penicillins differ from natural penicillins in all of the following respects except that both are

Accepted Answer

A)   Resistant to stomach acids.
B)   Resistant to penicillinase.
C)   Broad spectrum.
D)   Bactericidal.
E)   None of the above.F) A) and E)
G) None of the above

Question 16

Which of the following antimicrobial agents is recommended for use against fungal infections?

Accepted Answer

A)   Bacitracin
B)   Polymyxin
C)   Cephalosporin
D)   Amphotericin B
E)   PenicillinF) B) and C)
G) None of the above

Question 17

Which of the following does not affect eukaryotic cells?

Accepted Answer

A)   Antifungal drugs
B)   Antihelminthic drugs
C)   Antiprotozoan drugs
D)   Nucleotide analogs
E)   None of the aboveF) C) and E)
G) A) and D)

Question 18

Most of the available antimicrobial agents are effective against

Accepted Answer

A)   Viruses.
B)   Bacteria.
C)   Protozoa.
D)   Fungi.
E)   All of the above.F) A) and D)
G) A) and E) B

Question 19

Penicillin was considered a "miracle drug" for all of the following reasons except

Accepted Answer

A)   It doesn't affect eukaryotic cells.
B)   It inhibits gram- positive cell wall synthesis.
C)   It was the first antibiotic.
D)   It has selective toxicity.
E)   None of the above.F) All of the above
G) B) and C)

Question 20

More than half of our antibiotics are

Accepted Answer

A)   Produced by Fleming.
B)   Produced by fungi.
C)   Produced by bacteria.
D)   Synthesized in laboratories.
E)   None of the above.F) C) and E)
G) C) and D)

Exam 20: Antimicrobial Drugs

Which of the following would be selective against the tubercle bacillus?

Correct Answer
verified

Figure 20.5 -If the compound shown in Figure 20.5 is the substrate for a particular enzyme, which of the drugs would be the most effective competitive inhibitor?

Correct Answer
verified

Protozoan and helminthic diseases are difficult to treat because

Correct Answer
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Correct Answer
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A

Which one of the following does not belong with the others?

Correct Answer
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Which of the following antibiotics is not bactericidal?

Correct Answer
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Figure 20.4 -The antibiotic streptomycin binds to the 30S subunit of the ribosome as shown in Figure 20.4. The effect is to

Correct Answer
verified

Use of antibiotics in animal feed leads to antibiotic- resistant bacteria because

Correct Answer
verified

All of the following statements about drug resistance are true except

Correct Answer
verified

Which of the following antibiotics causes misreading of mRNA?

Correct Answer
verified

Drug resistance occurs

Correct Answer
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Which of the following is not bactericidal?

Correct Answer
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D

Which of the following methods of action would be bacteriostatic?

Correct Answer
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Correct Answer
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Semisynthetic penicillins differ from natural penicillins in all of the following respects except that both are

Correct Answer
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Which of the following antimicrobial agents is recommended for use against fungal infections?

Correct Answer
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Which of the following does not affect eukaryotic cells?

Correct Answer
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Most of the available antimicrobial agents are effective against

Correct Answer
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B

Penicillin was considered a "miracle drug" for all of the following reasons except

Correct Answer
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More than half of our antibiotics are

Correct Answer
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Exam 20: Antimicrobial Drugs

Which of the following would be selective against the tubercle bacillus?

Correct AnswerverifiedShow Answer

Figure 20.5 -If the compound shown in Figure 20.5 is the substrate for a particular enzyme, which of the drugs would be the most effective competitive inhibitor?

Correct AnswerverifiedShow Answer

Protozoan and helminthic diseases are difficult to treat because

Correct AnswerverifiedShow Answer

Correct AnswerverifiedA

Which one of the following does not belong with the others?

Correct AnswerverifiedShow Answer

Which of the following antibiotics is not bactericidal?

Correct AnswerverifiedShow Answer

Figure 20.4 -The antibiotic streptomycin binds to the 30S subunit of the ribosome as shown in Figure 20.4. The effect is to

Correct AnswerverifiedShow Answer

Use of antibiotics in animal feed leads to antibiotic- resistant bacteria because

Correct AnswerverifiedShow Answer

All of the following statements about drug resistance are true except

Correct AnswerverifiedShow Answer

Which of the following antibiotics causes misreading of mRNA?

Correct AnswerverifiedShow Answer

Drug resistance occurs

Correct AnswerverifiedShow Answer

Which of the following is not bactericidal?

Correct AnswerverifiedD

Which of the following methods of action would be bacteriostatic?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Semisynthetic penicillins differ from natural penicillins in all of the following respects except that both are

Correct AnswerverifiedShow Answer

Which of the following antimicrobial agents is recommended for use against fungal infections?

Correct AnswerverifiedShow Answer

Which of the following does not affect eukaryotic cells?

Correct AnswerverifiedShow Answer

Most of the available antimicrobial agents are effective against

Correct AnswerverifiedB

Penicillin was considered a "miracle drug" for all of the following reasons except

Correct AnswerverifiedShow Answer

More than half of our antibiotics are

Correct AnswerverifiedShow Answer

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A

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D

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B

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