Microbiology MCQs
Microbiology MCQs cover bacteriology, virology, mycology, parasitology, and immunology, testing pathogen identification, microbial physiology, and infection control. Ideal for MDCAT, FCPS, NTS, and USMLE preparation, these quizzes boost academic knowledge, clinical skills, and exam success.
Q: Microaerophilic bacteria require
A) Normal oxygen levels
B) No oxygen
C) Reduced oxygen levels
D) High carbon dioxide
✅ Correct Answer: C
Explanation: Microaerophiles grow best in environments with lower oxygen than atmospheric levels.
Q: A positive Mantoux test indicates
A) Hepatitis infection
B) HIV exposure
C) Malaria immunity
D) Tuberculosis exposure
✅ Correct Answer: D
Explanation: A positive tuberculin skin test suggests prior exposure or latent infection with Mycobacterium tuberculosis.
Q: An exotoxin is typically
A) Produced only during spore formation
B) Secreted by bacteria
C) Found only in viruses
D) A structural component of the cell wall
✅ Correct Answer: B
Explanation: Exotoxins are proteins secreted by bacteria that can cause damage to the host.
Q: The site of ATP generation in bacteria is the
A) Cell wall
B) Ribosomes
C) Nucleus
D) Cytoplasmic membrane
✅ Correct Answer: D
Explanation: Since bacteria lack mitochondria, energy production occurs at the cytoplasmic membrane.
Q: Haemophilus influenzae requires
A) Salt agar
B) No oxygen
C) EMB agar
D) Chocolate agar
✅ Correct Answer: D
Explanation: Haemophilus influenzae grows on chocolate agar due to its requirement for growth factors X (hemin) and V (NAD).