MICROBIOLOGY FINAL EXAM -
JERSEY COLLEGE 2026 QUESTIONS
AND ANSWERS
1. Which of the following organisms is characterized by its ability to produce coagulase, an
enzyme that clots blood plasma?
A. Staphylococcus epidermidis
B. Streptococcus pyogenes
C. Enterococcus faecalis
D. Staphylococcus aureus
Answer: D
Conceptual Explanation: Staphylococcus aureus is the primary pathogen in its genus that
produces coagulase, which helps it evade the immune system by forming fibrin clots.
2. Which antibiotic mechanism of action involves the inhibition of the 50S ribosomal subunit?
A. Penicillin
B. Tetracycline
C. Erythromycin
,D. Gentamicin
Answer: C
Conceptual Explanation: Macrolides like erythromycin bind to the 50S subunit of the
ribosome to inhibit protein synthesis, whereas tetracyclines and aminoglycosides bind to
the 30S subunit.
3. In a Gram stain, what is the function of the iodine solution?
A. Primary stain
B. Counterstain
C. Decolorizer
D. Mordant
Answer: D
Conceptual Explanation: Iodine acts as a mordant, forming a complex with crystal violet
that gets trapped in the thick peptidoglycan layer of Gram-positive bacteria.
4. Which of the following is an obligate intracellular pathogen?
A. Clostridium difficile
B. Escherichia coli
C. Bacillus anthracis
D. Chlamydia trachomatis
, Answer: D
Conceptual Explanation: Chlamydia species are obligate intracellular bacteria because
they cannot synthesize their own ATP and must inhabit host cells.
5. Which type of hypersensitivity reaction involves IgE-mediated mast cell degranulation?
A. Type III
B. Type II
C. Type I
D. Type IV
Answer: C
Conceptual Explanation: Type I hypersensitivity is an immediate allergic reaction
involving IgE antibodies and the release of histamine from mast cells.
6. The ‘Beta-lactam’ ring is a structural component of which group of antibiotics?
A. Cephalosporins
B. Quinolones
C. Sulfonamides
D. Tetracyclines
Answer: A
JERSEY COLLEGE 2026 QUESTIONS
AND ANSWERS
1. Which of the following organisms is characterized by its ability to produce coagulase, an
enzyme that clots blood plasma?
A. Staphylococcus epidermidis
B. Streptococcus pyogenes
C. Enterococcus faecalis
D. Staphylococcus aureus
Answer: D
Conceptual Explanation: Staphylococcus aureus is the primary pathogen in its genus that
produces coagulase, which helps it evade the immune system by forming fibrin clots.
2. Which antibiotic mechanism of action involves the inhibition of the 50S ribosomal subunit?
A. Penicillin
B. Tetracycline
C. Erythromycin
,D. Gentamicin
Answer: C
Conceptual Explanation: Macrolides like erythromycin bind to the 50S subunit of the
ribosome to inhibit protein synthesis, whereas tetracyclines and aminoglycosides bind to
the 30S subunit.
3. In a Gram stain, what is the function of the iodine solution?
A. Primary stain
B. Counterstain
C. Decolorizer
D. Mordant
Answer: D
Conceptual Explanation: Iodine acts as a mordant, forming a complex with crystal violet
that gets trapped in the thick peptidoglycan layer of Gram-positive bacteria.
4. Which of the following is an obligate intracellular pathogen?
A. Clostridium difficile
B. Escherichia coli
C. Bacillus anthracis
D. Chlamydia trachomatis
, Answer: D
Conceptual Explanation: Chlamydia species are obligate intracellular bacteria because
they cannot synthesize their own ATP and must inhabit host cells.
5. Which type of hypersensitivity reaction involves IgE-mediated mast cell degranulation?
A. Type III
B. Type II
C. Type I
D. Type IV
Answer: C
Conceptual Explanation: Type I hypersensitivity is an immediate allergic reaction
involving IgE antibodies and the release of histamine from mast cells.
6. The ‘Beta-lactam’ ring is a structural component of which group of antibiotics?
A. Cephalosporins
B. Quinolones
C. Sulfonamides
D. Tetracyclines
Answer: A
