Explore topic-wise MCQs in Microbiology.

This section includes 10 Mcqs, each offering curated multiple-choice questions to sharpen your Microbiology knowledge and support exam preparation. Choose a topic below to get started.

1.

Which of the following is the example of Gram-negative bacteria?

A. Lactobacillus
B. Eschericia coli
C. Staphylococcus aureus
D. Bacillus subtilis
Answer» C. Staphylococcus aureus
2.

In Gram-staining, iodine is used as a ______________

A. fixative
B. mordant
C. solublizer
D. stain
Answer» C. solublizer
3.

Which of the following is the example of Gram-negative bacteria?

A. Lactobacillus
B. Eschericia coli
C. Staphylococcus aureus
D. Bacillus subtilis
Answer» C. Staphylococcus aureus
4.

In Gram-staining, iodine is used as a______________

A. fixative
B. mordant
C. solublizer
D. stain
Answer» C. solublizer
5.

Which of the staining technique helps in demonstrating spore structure in bacteria as well as free spores?

A. Acid-fast stain
B. Endospore stain
C. Capsule stain
D. Flagella stain
Answer» C. Capsule stain
6.

Gram-positive bacteria are usually more susceptible to?

A. streptomycin
B. tetracyclin
C. penicillin
D. ampicillin
Answer» D. ampicillin
7.

Which of the following are true for Gram-negative bacteria?

A. upon alcohol treatment, the permeability of the cell wall increases
B. crystal violet-iodine (CV-I) complex is extracted
C. pore size decreases and the CV-I complex cannot be extracted
D. alcohol treatment increases the permeability of the cell wall and the CV-I complex can be extracted
Answer» E.
8.

Which bacteria appears purple-violet colour after staining?

A. Gram-positive
B. Gram-negative
C. Both Gram-positive and Gram-negative
D. Neither Gram-positive nor Gram-negative
Answer» B. Gram-negative
9.

What is the correct order of staining reagents in Gram-Staining?

A. Crystal violet, alcohol, iodine solution, safranin
B. Crystal violet, iodine solution, alcohol, safranin
C. Crystal violet, safranin, alcohol, iodine solution
D. Iodine solution, crystal violet, alcohol, safranin
Answer» C. Crystal violet, safranin, alcohol, iodine solution
10.

The dye eosinate of methylene blue belongs to which group?

A. Acidic dye
B. Basic dye
C. Neutral dye
D. Oxazine dye
Answer» D. Oxazine dye