,BIOD 351 Module 6 | Pharmacology | Portage Learning
| Questions & Verified Answers | 2026 Edition
1. Which term describes a drug that directly kills bacteria?
A) Bacteriostatic
B) Bactericidal
C) Synergistic
D) Prophylactic
Correct Answer: Bactericidal
Rationale: Bactericidal agents cause bacterial death directly by destroying the bacterial cell wall, cell
membrane, or interfering with essential cellular processes. Bacteriostatic agents only inhibit bacterial
growth, requiring the host's immune system to eliminate the bacteria. Understanding this distinction is
fundamental to selecting appropriate antimicrobial therapy.
2. What is "Empiric Therapy"?
A) Treatment based on a confirmed lab culture
B) Treatment given to prevent an infection before it starts
C) Treatment started based on clinical judgment before lab results are ready
D) Treatment used only for viral infections
Correct Answer: Treatment started based on clinical judgment before lab results are ready
Rationale: Empiric therapy is an "educated guess" used to treat likely pathogens immediately to prevent
the patient's condition from worsening while waiting for culture and sensitivity results. Once lab results
are available, therapy may be narrowed to targeted treatment.
3. Gram-negative bacteria appear pink/red after staining because:
A) They have a very thick peptidoglycan layer
B) They lack an outer membrane
,C) They have a thin peptidoglycan layer and a complex outer membrane
D) They do not absorb any dye
Correct Answer: They have a thin peptidoglycan layer and a complex outer membrane
Rationale: Gram-negative bacteria have a thin peptidoglycan layer and an outer membrane that does
not retain the purple crystal violet stain during the Gram-stain procedure. Instead, they take up the pink
safranin counterstain. This structural difference has important implications for antibiotic susceptibility.
4. A "Broad-Spectrum" antibiotic is one that:
A) Only kills one specific type of bacteria
B) Is effective against a wide range of both Gram-positive and Gram-negative bacteria
C) Is used only for fungal infections
D) Has very few side effects
Correct Answer: Is effective against a wide range of both Gram-positive and Gram-negative bacteria
Rationale: Broad-spectrum antibiotics are effective against a wide variety of both Gram-positive and
Gram-negative bacteria. Narrow-spectrum antibiotics target specific types of bacteria. Broad-spectrum
agents are often used in empiric therapy but can disrupt normal flora and promote resistance.
5. Which of the following is NOT a mechanism of action associated with antibiotics?
A) Inhibition of cell wall synthesis
B) Inhibition of protein synthesis
C) Interference with carbohydrate synthesis
D) Interference with DNA replication
Correct Answer: Interference with carbohydrate synthesis
, Rationale: Antibiotics work through several mechanisms including inhibition of cell wall synthesis
(penicillins), protein synthesis (macrolides, tetracyclines), DNA replication (fluoroquinolones), and folate
synthesis (sulfonamides). Interference with carbohydrate synthesis is not a recognized mechanism of
antibiotic action.
6. Define what an antibiotic is.
A) A drug that kills viruses
B) A drug that has the ability to destroy or interfere with the development of a living organism, typically
bacteria
C) A drug that only treats fungal infections
D) A drug that boosts the immune system
Correct Answer: A drug that has the ability to destroy or interfere with the development of a living
organism, typically bacteria
Rationale: Antibiotics are drugs that destroy or interfere with the development of living organisms,
typically bacteria. They can be bactericidal (kill bacteria) or bacteriostatic (inhibit bacterial growth).
Antibiotics are not effective against viruses.
7. Enterococcus faecalis is classified as:
A) Gram-positive
B) Gram-negative
C) Acid-fast
D) Anaerobic
Correct Answer: Gram-positive
Rationale: Enterococcus faecalis is a Gram-positive bacterium that appears purple after Gram staining. It
is a common cause of urinary tract infections and can be resistant to many antibiotics, including
vancomycin (VRE).
8. Escherichia coli is classified as:
| Questions & Verified Answers | 2026 Edition
1. Which term describes a drug that directly kills bacteria?
A) Bacteriostatic
B) Bactericidal
C) Synergistic
D) Prophylactic
Correct Answer: Bactericidal
Rationale: Bactericidal agents cause bacterial death directly by destroying the bacterial cell wall, cell
membrane, or interfering with essential cellular processes. Bacteriostatic agents only inhibit bacterial
growth, requiring the host's immune system to eliminate the bacteria. Understanding this distinction is
fundamental to selecting appropriate antimicrobial therapy.
2. What is "Empiric Therapy"?
A) Treatment based on a confirmed lab culture
B) Treatment given to prevent an infection before it starts
C) Treatment started based on clinical judgment before lab results are ready
D) Treatment used only for viral infections
Correct Answer: Treatment started based on clinical judgment before lab results are ready
Rationale: Empiric therapy is an "educated guess" used to treat likely pathogens immediately to prevent
the patient's condition from worsening while waiting for culture and sensitivity results. Once lab results
are available, therapy may be narrowed to targeted treatment.
3. Gram-negative bacteria appear pink/red after staining because:
A) They have a very thick peptidoglycan layer
B) They lack an outer membrane
,C) They have a thin peptidoglycan layer and a complex outer membrane
D) They do not absorb any dye
Correct Answer: They have a thin peptidoglycan layer and a complex outer membrane
Rationale: Gram-negative bacteria have a thin peptidoglycan layer and an outer membrane that does
not retain the purple crystal violet stain during the Gram-stain procedure. Instead, they take up the pink
safranin counterstain. This structural difference has important implications for antibiotic susceptibility.
4. A "Broad-Spectrum" antibiotic is one that:
A) Only kills one specific type of bacteria
B) Is effective against a wide range of both Gram-positive and Gram-negative bacteria
C) Is used only for fungal infections
D) Has very few side effects
Correct Answer: Is effective against a wide range of both Gram-positive and Gram-negative bacteria
Rationale: Broad-spectrum antibiotics are effective against a wide variety of both Gram-positive and
Gram-negative bacteria. Narrow-spectrum antibiotics target specific types of bacteria. Broad-spectrum
agents are often used in empiric therapy but can disrupt normal flora and promote resistance.
5. Which of the following is NOT a mechanism of action associated with antibiotics?
A) Inhibition of cell wall synthesis
B) Inhibition of protein synthesis
C) Interference with carbohydrate synthesis
D) Interference with DNA replication
Correct Answer: Interference with carbohydrate synthesis
, Rationale: Antibiotics work through several mechanisms including inhibition of cell wall synthesis
(penicillins), protein synthesis (macrolides, tetracyclines), DNA replication (fluoroquinolones), and folate
synthesis (sulfonamides). Interference with carbohydrate synthesis is not a recognized mechanism of
antibiotic action.
6. Define what an antibiotic is.
A) A drug that kills viruses
B) A drug that has the ability to destroy or interfere with the development of a living organism, typically
bacteria
C) A drug that only treats fungal infections
D) A drug that boosts the immune system
Correct Answer: A drug that has the ability to destroy or interfere with the development of a living
organism, typically bacteria
Rationale: Antibiotics are drugs that destroy or interfere with the development of living organisms,
typically bacteria. They can be bactericidal (kill bacteria) or bacteriostatic (inhibit bacterial growth).
Antibiotics are not effective against viruses.
7. Enterococcus faecalis is classified as:
A) Gram-positive
B) Gram-negative
C) Acid-fast
D) Anaerobic
Correct Answer: Gram-positive
Rationale: Enterococcus faecalis is a Gram-positive bacterium that appears purple after Gram staining. It
is a common cause of urinary tract infections and can be resistant to many antibiotics, including
vancomycin (VRE).
8. Escherichia coli is classified as:
