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: Endotoxins are typically associated with
A) Viruses
B) Protozoa
C) Gram-negative bacteria
D) Gram-positive bacteria
✅ Correct Answer: C
Explanation: Endotoxins are components of the outer membrane of Gram-negative bacteria, specifically lipopolysaccharides.
Q: Lysozyme in human tears targets
A) RNA
B) Flagella
C) DNA
D) Peptidoglycan
✅ Correct Answer: D
Explanation: Lysozyme breaks down the peptidoglycan layer in bacterial cell walls, offering protection against infection.
Q: Helicobacter pylori is linked to the development of
A) Pneumonia
B) Meningitis
C) Tuberculosis
D) Peptic ulcers
✅ Correct Answer: D
Explanation: Helicobacter pylori infects the stomach lining and is strongly associated with peptic ulcer disease.
Q: The first antibody to appear in response to an infection is
A) IgE
B) IgA
C) IgM
D) IgG
✅ Correct Answer: C
Explanation: IgM is produced early during infection and is a marker of recent or acute immune response.
Q: Bacterial transformation involves
A) Viral infection
B) Uptake of naked DNA
C) Conjugation
D) Cell fusion
✅ Correct Answer: B
Explanation: Transformation allows bacteria to take up and incorporate free DNA fragments from the environment.