Explore topic-wise MCQs in Microbiology.

This section includes 151 Mcqs, each offering curated multiple-choice questions to sharpen your Microbiology knowledge and support exam preparation. Choose a topic below to get started.

1.

In hospitals, surgical instruments and plastics are washed with

A. Ethylene oxide
B. Iodine
C. Tincture
D. Chlorine
Answer» B. Iodine
2.

Cephalosporins and Penicillins interfere with which of the following?

A. Protein synthesis
B. DNA function
C. Cell membrane function
D. Cell wall synthesis
Answer» E.
3.

Drugs that inhibit cross linking step in synthesis of murine, inhibits activity of enzyme, known as

A. Trans peptidases
B. Amylase
C. Protease
D. Lipase
Answer» B. Amylase
4.

Pore size of 'nitrocellulose' is

A. 0.23 µm
B. 0.22 µm
C. 0.21 µm
D. 0.26 µm
Answer» C. 0.21 µm
5.

With which of the following aminoglycosides interfere?

A. Protein synthesis
B. DNA function
C. Cell wall synthesis
D. Cell membrane function
Answer» B. DNA function
6.

Staphylococcus epidermidis causes an infection that can be treated with

A. Cephalosporin
B. Vancomycin
C. Bacitracin
D. Cycloserine
Answer» C. Bacitracin
7.

Meningitis results from meninges become affected through

A. virus only
B. bacteria only
C. fungi
D. virus and bacteria
Answer» E.
8.

Broad-spectrum antibiotics are developed through

A. erythromycins
B. cephalosporin
C. Tetacyclines
D. Penicillin
Answer» D. Penicillin
9.

Which of the following tests is used to determine the minimal lethal concentration?

A. Broth dilution test
B. Agar dilution test
C. Dilution susceptibility tests
D. All of these
Answer» E.
10.

Which of the following is not a semi synthetic chemotherapeutic agent?

A. Ampicillin
B. Carbenicillin
C. Penicillin
D. Sulfonamide
Answer» D. Sulfonamide
11.

In penicillin production, the pH of culture medium is maintained between

A. 5 and 6
B. 4 and 6
C. 6 and 7
D. 4 and 5
Answer» B. 4 and 6
12.

Malarial parasites are treated with drug containing

A. penicillin
B. paludrine
C. aspirin
D. morphine
Answer» C. aspirin
13.

A broad-spectrum antibiotic such as chloramphenicol is one that

A. kills both Gram positive and Gram negative bacteria
B. kills all bacteria
C. kills numerous types of microbes
D. kills all microorganisms
Answer» D. kills all microorganisms
14.

A chemical, used for removal of microorganisms from mucous membrane and skin, called as

A. Detergents
B. Alcohol
C. Pesticides
D. Antiseptics
Answer» E.
15.

'surgical staphylococcal' wound infection is prevented by drug

A. Rifampin
B. Cefazolin
C. Amoxicillin
D. Erythromycin
Answer» C. Amoxicillin
16.

The mode of action of polymyxin is to

A. inhibit protein synthesis
B. inhibit DNA synthesis
C. injury to the plasma membrane
D. inhibit folic acid synthesis
Answer» D. inhibit folic acid synthesis
17.

Penicillin production is optimum in

A. batch operation systems
B. continuous operation systems
C. discontinuous operation system
D. unique operation system
Answer» B. continuous operation systems
18.

To prevent from 'pathogens' first line defense mechanism is called as

A. Adaptive immunity
B. Innate immunity
C. Resistance
D. Defense
Answer» C. Resistance
19.

For purification of swimming pools and water supplies of chemical used is

A. Alcohol
B. Chlorine
C. Iodine
D. Heavy metals
Answer» C. Iodine
20.

Which of the following is not β-lactamase-resistant penicillin?

A. Oxacillin
B. Nafcillin
C. Carbenicillin
D. Methicillin
Answer» D. Methicillin
21.

The antibiotics not having good activity against Enterobacteriaceae is

A. clindamycin
B. cefoxitin
C. trimethoprim-sulphamethoxazole
D. ciprofloxacin
Answer» B. cefoxitin
22.

Drugs that are structural analogue of Para-amino benzoic acid, included

A. Streptogramins
B. Telithromycin
C. Sulfonamides
D. Linezolid
Answer» D. Linezolid
23.

To produce penicillin, the main fermentable source in the culture is

A. glucose
B. lactose
C. sulphate
D. sugars
Answer» C. sulphate
24.

Capability of an organism to resist a particular toxin or disease by action of defense mechanism is called

A. Resistance
B. Immunity
C. Ability
D. Defense
Answer» C. Ability
25.

Which of the following may cause resistance to penicillin?

A. Impermeability of cell envelope
B. Production of β-lactamases by bacteria
C. Alteration or lack of penicillin-binding proteins
D. All of the above
Answer» E.
26.

Amphotericin B and polymyxin interfere with

A. cell wall synthesis
B. protein synthesis
C. cell membrane function
D. DNA function
Answer» D. DNA function
27.

Competition of Para-aminobenzoic acid and sulfonamides, occupying active sites of enzyme, known as

A. Dihydropteroate synthetase
B. Transferase
C. Lipase
D. Peptidase
Answer» B. Transferase
28.

Monobactams have tremendous activity against gram-negative rods, included

A. Bacillus
B. Diplobacillus
C. Pseudomonas
D. Streptomyces
Answer» D. Streptomyces
29.

Drugs useful against bacteria resistant to penicillin include

A. Cephalosporin only
B. Erythromycins only
C. Augmentin
D. Cephalosporin and Erythromycins
Answer» E.
30.

In order to combat virus-produced diseases,

A. antibiotics shall be administered
B. depressant drugs shall be administered
C. amphetamines shall be administered
D. body's own immunity system shall combat
Answer» E.
31.

Mycoplasma and Legionella are causative agents for 'pneumonia' that is treated by

A. Streptomycin
B. Erythromycin
C. Clindamycin
D. Amikacin
Answer» C. Clindamycin
32.

'Vancomycin' is effective against

A. Gram negative bacteria
B. Gram positive bacteria
C. Gram negative rods
D. Gram positive rods
Answer» C. Gram negative rods
33.

Both penicillin and fluoroquinolones

A. bind to and inactivate a bacterial protein
B. inhibit the cross-linking of peptidoglycan
C. are inactivated by β-lactamase
D. must be transported into the cytoplasm in order to act
Answer» B. inhibit the cross-linking of peptidoglycan
34.

Polyene antibiotics are

A. large ring structures
B. β-lactam - thiazolidine ring
C. small ring structures
D. any of these
Answer» B. β-lactam - thiazolidine ring
35.

Bond between 50s ribosomal subunit and chloramphenicol, during inhibition of protein synthesis is at active site of enzyme, named as

A. Peptidase
B. Transferase
C. Amylase
D. Lipase
Answer» C. Amylase
36.

The compound(s) which act(s) as metabolic antagonist is/are

A. trimethoprim
B. sulphonamides
C. both (a) and (b)
D. none of these
Answer» D. none of these
37.

Most 'cephalosporin' are products derived from molds of genus

A. Streptomyces
B. Cephalosporium
C. Actinomycetes
D. Algae
Answer» C. Actinomycetes
38.

A ? lactam drug , having same mechanism of action as penicillin, known as

A. Cephalosporin
B. Carbapenems
C. Monobactams
D. Vancomycin
Answer» B. Carbapenems
39.

The susceptibility of a microorganism to antibiotics and other chemotherapeutic agents can be determined by using

A. tube dilution technique
B. paper disk plate
C. both (a) and (b)
D. none of these
Answer» D. none of these
40.

Which of the following is not an example of potent antitumer agents?

A. Anthramycin
B. Sibromycin
C. Neothramycin
D. Erythromycin
Answer» E.
41.

Passage of 'antibodies' from one person to another is called

A. Passive immunity
B. Active immunity
C. Innate immunity
D. Defense
Answer» B. Active immunity
42.

During 'pasteurization' milk is heated for 30 minutes at

A. 67°C
B. 63°C
C. 62°C
D. 61°C
Answer» E.
43.

'Egrosterol' synthesis is terminated by an antifungal drug, called as

A. Nystatin
B. Amphotericin B
C. Azoles
D. Flucytosine
Answer» D. Flucytosine
44.

A drug that is approved by government, in treating a particular disease, is called

A. Drug therapy
B. Chemotherapy
C. First line drug
D. Second line drug
Answer» D. Second line drug
45.

Before ' immunization' skin is cleaned with

A. Detergents
B. Insecticides
C. Alcohol
D. Ethanol
Answer» E.
46.

Method used for sterilization of solutions is called

A. Sterilization
B. Autoclaving
C. Filtration
D. Radiations
Answer» D. Radiations
47.

A parenteral route of drug administration refers to

A. oral
B. nonoral
C. intravenously
D. intramuscularly
Answer» C. intravenously
48.

Which of the following drugs may show plasmid-mediated resistance?

A. Nalidixic acid
B. Ampicillin
C. Rifampicin
D. Methicillin
Answer» C. Rifampicin
49.

Vancomycin inhibits peptidoglycan synthesis by binding

A. D-alanyl - D-alanine
B. alanine racemase
C. D-alanyl - D-alanine synthetase
D. amidase
Answer» B. alanine racemase
50.

Most antibiotics are isolated from

A. viruses
B. aquatic microorganisms
C. soil microorganisms
D. plants
Answer» D. plants