QUIZ 4 REVISION
Capsule Staining Quiz
1. What is the primary purpose of capsule staining?
a) To differentiate between Gram-positive and Gram-negative bacteria
b) To highlight the presence of endospores
c) To demonstrate the presence of a capsule around bacterial cells
d) To determine bacterial motility
2. Which of the following is true about bacterial capsules?
a) They are composed of peptidoglycan.
b) They are easily stained using basic dyes.
c) They help bacteria evade the immune system.
d) They are required for bacterial survival.
3. Why is heat-fixing not used in capsule staining?
a) Heat distorts the cell shape.
b) Capsules are destroyed by heat.
c) Heat causes the capsule to shrink and become invisible.
d) All of the above.
4. What is the role of Congo red in capsule staining?
a) It stains the capsule directly.
b) It stains the bacterial cell.
c) It acts as a pH indicator and provides a contrasting background.
d) It fixes the bacterial cells to the slide.
5. At an acidic pH, Congo red turns:
a) Red
b) Blue
c) Purple
d) Green
6. Which of the following stains the bacterial cell in capsule staining?
a) Congo red
b) Acid fuchsin
c) Crystal violet
d) Malachite green
7. What is the expected color of the bacterial cells after capsule staining?
a) Blue
b) Red/Pink
c) Clear
d) Green
8. What does the capsule look like under the microscope after staining?
a) Pink cells surrounded by a clear halo on a blue background
b) Purple cells with a black capsule
c) Blue cells with a red capsule
d) Green cells with a white halo
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