Question 1

Which of the following best explains why most antimicrobial drugs are effective against prokaryotes but not viruses?

Accepted Answer

Viruses lack the metabolic machinery targeted by most antibiotics.

Question 2

A patient is prescribed a 10-day course of antibiotics but stops taking them after 5 days when symptoms improve. What is the most likely consequence of this action?

Accepted Answer

The more resistant portion of the pathogen population may survive and proliferate.

Question 3

Which of the following is NOT a characteristic of an ideal antimicrobial drug?

Accepted Answer

It requires refrigeration for storage.

Question 4

Why is selective toxicity an important property for antimicrobial drugs?

Accepted Answer

It ensures the drug targets the microbe without harming the host.

Question 5

Which of the following drugs targets bacterial cell wall synthesis?

Accepted Answer

Penicillin

Question 6

A hospital survey found that over 60% of antibiotics were prescribed in the wrong dosage or for the wrong application. What is a likely public health consequence of this practice?

Accepted Answer

Increased prevalence of antibiotic-resistant microbes.

Question 7

Which of the following best describes the mechanism by which drug resistance develops in microbial populations?

Accepted Answer

Selection of resistant individuals within a diverse population.

Question 8

Which of the following is a broad-spectrum antibiotic?

Accepted Answer

Tetracycline

Question 9

Why is it important to use all antibiotics for the fully prescribed time, even if symptoms improve?

Accepted Answer

To ensure that the more resistant portion of the pathogen population is eliminated.

Question 10

Which of the following is a target of sulfa drugs in bacteria?

Accepted Answer

Enzymes involved in folic acid synthesis

Question 11

A patient with tuberculosis is treated with a combination of four drugs: isoniazid, rifampin, pyrazinamide, and ethambutol. What is the main reason for using this multi-drug therapy?

Accepted Answer

It greatly reduces the likelihood that the bacteria will develop resistance to all drugs simultaneously.

Question 12

Which of the following best explains why normal flora disturbance by antibiotics can lead to superinfection?

Accepted Answer

Antibiotics eliminate non-pathogenic microbes, allowing resistant pathogens to proliferate.

Question 13

Which of the following is a plausible reason why microbes should not readily develop resistance to an ideal antimicrobial drug?

Accepted Answer

To maintain the long-term effectiveness of the drug.

Question 14

Which of the following is a narrow spectrum antibiotic?

Accepted Answer

Isoniazid

Question 15

Which of the following best describes the role of ribosomes as a target for antibiotics?

Accepted Answer

Antibiotics like streptomycin and tetracycline inhibit protein synthesis by binding to bacterial ribosomes.

Question 16

Which of the following equations best represents the probability $$P$$ that a single bacterial cell will develop resistance to all four drugs in a combination therapy, assuming independent mutation rates $$p_1$$, $$p_2$$, $$p_3$$, $$p_4$$ for each drug?

Accepted Answer

$$P = p_1$ 	imes p_2$ 	imes p_3$ 	imes p_4$

Question 17

Which of the following is a common misconception about the use of broad-spectrum antibiotics?

Accepted Answer

They are less likely to cause resistance than narrow-spectrum antibiotics.

Question 18

Which of the following best explains why fungi, protozoans, and helminths are less susceptible to antibiotics that target prokaryotic cells?

Accepted Answer

They have 80S ribosomes and eukaryotic cell structures, making them less affected by drugs targeting prokaryotic features.

Question 19

Which of the following is a real-world strategy to reduce the development of drug resistance in microbes?

Accepted Answer

Prescribing antibiotics only when necessary and ensuring full completion of therapy.

Question 20

Which of the following best describes the danger of horizontal gene transfer in the spread of antibiotic resistance?

Accepted Answer

Resistance genes can be transferred between different bacterial species, including pathogens.

Study Guide: Antimicrobial Drugs and Drug Resistance ~ Chp 20

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