Questions and Answers (Verified Answers) with
Rationales 2025
1. Which structure allows bacteria to adhere to surfaces and evade the
immune system?
A. Flagella
B. Capsule
C. Pili
D. Endospore
The capsule provides protection against phagocytosis and aids in
adherence to host tissues.
2. Which staining technique is used to differentiate between Gram-positive
and Gram-negative bacteria?
A. Acid-fast stain
B. Gram stain
C. Endospore stain
D. Simple stain
Gram staining distinguishes bacteria by differences in their cell wall
composition.
3. Which component of the bacterial cell wall is responsible for the rigidity of
Gram-positive bacteria?
, A. Peptidoglycan
B. Lipopolysaccharide
C. Teichoic acid
D. Mycolic acid
Gram-positive bacteria have thick layers of peptidoglycan that provide
structural integrity.
4. Which microorganism is a eukaryote?
A. Bacteria
B. Virus
C. Archaea
D. Fungi
Fungi are eukaryotic organisms with membrane-bound organelles and
nuclei.
5. What is the function of bacterial endospores?
A. Reproduction
B. Genetic transfer
C. Survival in harsh conditions
D. Movement
Endospores allow bacteria to survive extreme environments such as heat
and desiccation.
6. Which phase of the bacterial growth curve involves rapid cell division?
A. Lag phase
B. Log phase
C. Stationary phase