Jersey College Microbiology Final Exam Prep | 150
Essential Practice Test Questions & Detailed Answers
| Covers Bacteria, Virology, Immunology & Infection
Control
Domain 1: Foundations, Cell Structure & Microscopy (Questions 1–30)
1. Which component of the Gram-negative cell wall functions as an endotoxin during
severe infections?
A) Teichoic acid
B) Peptidoglycan
C) Lipopolysaccharide (Lipid A)
D) Mycolic acid
Answer: C
2. What is the primary stain used in the traditional Gram stain procedure?
A) Safranin
B) Crystal violet
C) Carbolfuchsin
D) Methylene blue
Answer: B
,3. Which structure allows bacteria to survive harsh environmental conditions such as
extreme heat, desiccation, and chemical disinfectants?
A) Capsule
B) Endospore
C) Flagellum
D) Pili
Answer: B
4. Acid-fast staining is specifically used to identify organisms in the genus
Mycobacterium because their cell walls contain high concentrations of:
A) Pseudomurein
B) Lipopolysaccharide
C) Mycolic acid
D) Dipicolinic acid
Answer: C
5. Which bacterial organelle is primarily responsible for conjugation and horizontal
gene transfer?
A) Fimbriae
B) Sex pilus
C) Flagellum
D) Ribosome
Answer: B
,6. Penicillin is most effective against Gram-positive bacteria because it directly
inhibits:
A) 70S ribosomal subunit synthesis
B) Peptidoglycan cross-linking
C) DNA gyrase activity
D) Outer membrane assembly
Answer: B
7. Which structure prevents a bacterial cell from rupturing due to osmotic pressure in
a hypotonic environment?
A) Cell membrane
B) Glycocalyx
C) Cell wall
D) Inclusion body
Answer: C
8. An organism that produces an extracellular capsule is able to evade host defenses
primarily by:
A) Resisting phagocytosis
B) Neutralizing stomach acid
C) Inactivating antibiotics
D) Forming endospores
Answer: A
, 9. Prokaryotic ribosomes differ from eukaryotic cytoplasmic ribosomes in that
prokaryotic ribosomes are:
A) 80S (50S + 30S)
B) 70S (50S + 30S)
C) 80S (60S + 40S)
D) 70S (40S + 30S)
Answer: B
10. What role does iodine play in the Gram stain process?
A) Primary stain
B) Decolorizing agent
C) Counterstain
D) Mordant
Answer: D
11. Which bacterial arrangement consists of spherical cells in chain-like formations?
A) Staphylococci
B) Streptococci
C) Streptobacilli
D) Sarcinae
Answer: B
12. The bacterial plasma membrane is composed primarily of a:
Essential Practice Test Questions & Detailed Answers
| Covers Bacteria, Virology, Immunology & Infection
Control
Domain 1: Foundations, Cell Structure & Microscopy (Questions 1–30)
1. Which component of the Gram-negative cell wall functions as an endotoxin during
severe infections?
A) Teichoic acid
B) Peptidoglycan
C) Lipopolysaccharide (Lipid A)
D) Mycolic acid
Answer: C
2. What is the primary stain used in the traditional Gram stain procedure?
A) Safranin
B) Crystal violet
C) Carbolfuchsin
D) Methylene blue
Answer: B
,3. Which structure allows bacteria to survive harsh environmental conditions such as
extreme heat, desiccation, and chemical disinfectants?
A) Capsule
B) Endospore
C) Flagellum
D) Pili
Answer: B
4. Acid-fast staining is specifically used to identify organisms in the genus
Mycobacterium because their cell walls contain high concentrations of:
A) Pseudomurein
B) Lipopolysaccharide
C) Mycolic acid
D) Dipicolinic acid
Answer: C
5. Which bacterial organelle is primarily responsible for conjugation and horizontal
gene transfer?
A) Fimbriae
B) Sex pilus
C) Flagellum
D) Ribosome
Answer: B
,6. Penicillin is most effective against Gram-positive bacteria because it directly
inhibits:
A) 70S ribosomal subunit synthesis
B) Peptidoglycan cross-linking
C) DNA gyrase activity
D) Outer membrane assembly
Answer: B
7. Which structure prevents a bacterial cell from rupturing due to osmotic pressure in
a hypotonic environment?
A) Cell membrane
B) Glycocalyx
C) Cell wall
D) Inclusion body
Answer: C
8. An organism that produces an extracellular capsule is able to evade host defenses
primarily by:
A) Resisting phagocytosis
B) Neutralizing stomach acid
C) Inactivating antibiotics
D) Forming endospores
Answer: A
, 9. Prokaryotic ribosomes differ from eukaryotic cytoplasmic ribosomes in that
prokaryotic ribosomes are:
A) 80S (50S + 30S)
B) 70S (50S + 30S)
C) 80S (60S + 40S)
D) 70S (40S + 30S)
Answer: B
10. What role does iodine play in the Gram stain process?
A) Primary stain
B) Decolorizing agent
C) Counterstain
D) Mordant
Answer: D
11. Which bacterial arrangement consists of spherical cells in chain-like formations?
A) Staphylococci
B) Streptococci
C) Streptobacilli
D) Sarcinae
Answer: B
12. The bacterial plasma membrane is composed primarily of a: