Explore topic-wise MCQs in Microbiology.

This section includes 23 Mcqs, each offering curated multiple-choice questions to sharpen your Microbiology knowledge and support exam preparation. Choose a topic below to get started.

1.

Tyrocidines are more effective against ___________________

A. Gram-positive organisms
B. Gram-negative organisms
C. Mycoplasmas
D. Spirochetes
Answer» B. Gram-negative organisms
2.

Which of the following inhibits protein synthesis by combining with the 50S subunit ribosome?

A. Streptomycin
B. Tetracycline
C. Chloramphenicol
D. Penicillin
Answer» D. Penicillin
3.

Antibiotic produced by Streptomyces rimosus is _______________

A. chlortetracycline
B. oxytetracycline
C. tetracycline
D. doxycycline
Answer» C. tetracycline
4.

Streptomycin is produced by which of the following organisms?

A. Stretomyces noursei
B. Streptomyces nodosus
C. Streptomyces fradiae
D. Streptomyces griseus
Answer» E.
5.

Polymyxins inhibits the growth of the microbes by carrying out which of the following actions?

A. inhibition of cell-wall synthesis
B. damage to cytoplasmic membrane
C. inhibition of nucleic acid and protein synthesis
D. inhibition of specific enzyme systems
Answer» C. inhibition of nucleic acid and protein synthesis
6.

Which of the following interferes with the regeneration of the monophosphate form of bactoprenol from the pyrophosphate form?

A. Vancomycin
B. Ampicillin
C. Bacitracin
D. Cephalosporins
Answer» D. Cephalosporins
7.

Streptomyces orientalis produces which of the following antibiotics?

A. Cephalosporins
B. Cycloserine
C. Bacitracin
D. Vancomycin
Answer» E.
8.

Cell-wall biosynthesis is inhibited by antibiotics by inhibiting the biosynthesis of which of the following?

A. lipopolysaccharide
B. cellulose
C. peptidoglycan
D. proteins
Answer» D. proteins
9.

Bacterial cells grown in a medium exposed to high osmotic pressure, changes shape from rod-shaped to __________ shaped.

A. spherical
B. rod shaped
C. irregular
D. elongated
Answer» B. rod shaped
10.

POLYMYXINS_INHIBITS_THE_GROWTH_OF_THE_MICROBES_BY_CARRYING_OUT_WHICH_OF_THE_FOLLOWING_ACTIONS??$

A. inhibition of cell-wall synthesis
B. damage to cytoplasmic membrane
C. inhibition of nucleic acid and protein synthesis
D. inhibition of specific enzyme systems
Answer» C. inhibition of nucleic acid and protein synthesis
11.

Antibiotic produced by Streptomyces rimosus is _______________$

A. chlortetracycline
B. oxytetracycline
C. tetracycline
D. doxycycline
Answer» C. tetracycline
12.

Streptomycin is produced by which of the following organisms?$

A. Stretomyces noursei
B. Streptomyces nodosus
C. Streptomyces fradiae
D. Streptomyces griseus
Answer» E.
13.

Tyrocidines are more effective against ___________________

A. Gram-positive organisms
B. Gram-negative organisms
C. Mycoplasmas
D. Spirochetes
Answer» B. Gram-negative organisms
14.

Which of the following inhibits protein synthesis by combining with the 50S subunit ribosome?

A. Streptomycin
B. Tetracycline
C. Chloramphenicol
D. Penicillin
Answer» D. Penicillin
15.

Which of the following interferes with regeneration of the monophosphate form of bactoprenol from the pyrophosphate form?

A. Vancomycin
B. Ampicillin
C. Bacitracin
D. Cephalosporins
Answer» D. Cephalosporins
16.

Streptomyces orientalis produces which of the following antibiotics?

A. Cephalosporins
B. Cycloserine
C. Bacitracin
D. Vancomycin
Answer» E.
17.

Ampicillin is a bactericidal antibiotic.

A. True
B. False
Answer» B. False
18.

Benzylpenicillin is the chemical name for which of the following penicillin?

A. Penicillin G
B. Penicillin V
C. Penicillin F
D. Phenethicilin
Answer» B. Penicillin V
19.

Which of the following does not affect the activity of penicillin?

A. bile
B. hydrochloric acid
C. cysteine
D. sodium hydroxide
Answer» B. hydrochloric acid
20.

The crystalline sodium or potassium salts are slightly soluble in ___________

A. ether
B. dioxane
C. water
D. chloroform
Answer» E.
21.

Structurally all penicillins have only beta-lactam present in them.

A. True
B. False
Answer» C.
22.

Cell-wall biosynthesis is inhibited by antibiotics by inhibiting the biosynthesis of which of the following ?

A. lipopolysaccharide
B. cellulose
C. peptidoglycan
D. proteins
Answer» D. proteins
23.

Bacterial cells grown in a medium exposed to high osmotic pressure, changes shape from rod-shaped to __________ shaped.

A. spherical
B. rod shaped
C. irregular
D. elongated
Answer» B. rod shaped