Explore topic-wise MCQs in Microbiology.

This section includes 128 Mcqs, each offering curated multiple-choice questions to sharpen your Microbiology knowledge and support exam preparation. Choose a topic below to get started.

1.

A small poly peptide attract neutrophils and macrophages, towards infection site, named as

A. Chemokines
B. Gamma cells
C. Phagocytes
D. Prostaglandin
Answer» B. Gamma cells
2.

The fact that β-oxidation of fatty acids, occurs in the mitochondria whereas fatty acid synthesis occurs in the cytoplasmic matrix, is an example of regulation of enzymatic activity by the __________ mechanism.

A. compartmentation
B. induction
C. competitive inhibition
D. repression
Answer» E.
3.

Main side effect of drug 'cidodovir' is

A. Retinitis
B. Meningitis
C. Kidney failure
D. Heart failure
Answer» D. Heart failure
4.

'Cidofovir' is a nucleoside analogue of cytosine, lacks

A. Phosphate group
B. Purine
C. Ribose sugar
D. Hydrogen bonds
Answer» D. Hydrogen bonds
5.

When 'phagocytes' attacks infectious particles for destruction, process is called as

A. Opsonization
B. Defense
C. Destruction
D. Pathogenesis
Answer» B. Defense
6.

Main side effect of 'nevirapine' is

A. Hepatitis
B. Cancer
C. Skin rash
D. Skin infection
Answer» D. Skin infection
7.

Induction of tolerance mechanism(s) is/are

A. suppression
B. clonal deletion
C. clonal anergy
D. all of these
Answer» E.
8.

Hydrogen and oxygen release enormous amounts of energy when they react. Yet, hydrogen and oxygen can be mixed together in a balloon and nothing will happen. Why?

A. Competitive inhibitors are blocking the reaction from occurring in the active site
B. There must be contaminating elements in the balloon that prohibit the reaction from occurring
C. The energy of activation to form the transition-state complex is too high to allow the reaction to occur without assistance
D. all of the above
Answer» B. There must be contaminating elements in the balloon that prohibit the reaction from occurring
9.

The class of immunoglobulin, most abundant in body is

A. IgD
B. IgE
C. IgG
D. IgM
Answer» D. IgM
10.

When meningitis is suspected, test for diagnosis is carried out, known as

A. Spinal fluid culture
B. Stool Culture
C. Urine culture
D. Sputum culture
Answer» B. Stool Culture
11.

The class of immunoglobulins which can cross the placenta is

A. IgM
B. IgG
C. IgA
D. IgD
Answer» C. IgA
12.

Heat-labile class of immunoglobulins include

A. IgA
B. IgE
C. IgG
D. IgM
Answer» C. IgG
13.

'Shigella' and 'Campylobacter' are isolated by

A. Urine culture
B. Stool Culture
C. Spinal fluid culture
D. Blood culture
Answer» C. Spinal fluid culture
14.

Overactivity of Th cells may result into

A. autoimmunity
B. optimal antibody response
C. optimal cell-mediated response
D. none of the above
Answer» B. optimal antibody response
15.

The affinity of an enzyme for its substrate, when the enzyme has a Km of 0.50 M will be __________ than the affinity of an enzyme for its substrate when the enzyme has a Km of 0.05 M.

A. greater
B. lesser
C. approximately equal
D. half
Answer» C. approximately equal
16.

'Enfuvirtide' is an alternative name of

A. Fuzeon
B. Selzentry
C. Acyclovir
D. Vidarabine
Answer» B. Selzentry
17.

In which of the following cell mediated immunity (CMI) participates?

A. Delayed hypersensitivity reaction
B. Graft versus host reaction
C. Allograft rejection
D. All of the above
Answer» E.
18.

Immunosuppressive agent(s) is/are

A. Cyclosporine
B. Methotrexate
C. Anti-lymphocytic serum
D. All of these
Answer» E.
19.

Self reactive antibodies are not found in significant concentration in normal serum because

A. it is impossible to generate a self-reactive antibody
B. self reactive B cells are killed by CD8 T cells
C. B cells that are stimulated via their surface bound antibody in the absence of T cell help to commit suicide
D. self reactive B cells switch to IgA which is all secreted and not present in serum
Answer» D. self reactive B cells switch to IgA which is all secreted and not present in serum
20.

Which of the following is an example of autoimmune disease?

A. Rheumatoid arthritis
B. Systemic lupus erythematosus
C. Polyarteritis nodosa
D. All of the above
Answer» E.
21.

An enzyme that is always produced, regardless of the presence of substrates or the end products, is called

A. a constitutive enzyme
B. an isoenzyme
C. a repressible enzyme
D. an allosteric enzyme
Answer» B. an isoenzyme
22.

Antibodies are produced by

A. lymphocytes
B. phagocytes
C. monocytes
D. thrombocytes
Answer» B. phagocytes
23.

Attachment of 'erythrocytes' to surface of virally infected cell is termed as

A. Interference
B. Hemadsorption
C. Neutralization
D. Complement fixation
Answer» C. Neutralization
24.

Negative phase is observed in

A. secondary humoral response
B. primary humoral response
C. both (a) and (b)
D. none of the above
Answer» B. primary humoral response
25.

Which of the following is the phylogenetically oldest immunoglobulin?

A. IgE
B. IgM
C. IgG
D. All are similar
Answer» C. IgG
26.

Which of the following lymphokine(s) is secreted by delayed-type-hypersensitivity cells?

A. Macrophage stimulating factor
B. Migration inhibiting factor
C. Macrophage activating factor
D. All of the above
Answer» E.
27.

If person's own defense mechanism produces antibodies against infection or vaccination, immunity is termed as

A. Defense mechanism
B. Active immunity
C. Passive immunity
D. Drug therapy
Answer» C. Passive immunity
28.

Anti-Rh antibodies are

A. IgG type
B. IgA type
C. IgE type
D. IgD type
Answer» B. IgA type
29.

Which is not a function of IgG?

A. Major antibody in serum
B. First antibody type produced against an antigen during the primary antibody response
C. Activates or fixes complement
D. Involved in opsonization
Answer» C. Activates or fixes complement
30.

A duration of time, a specific antibody develops, becoming detachable in blood, known as

A. Serology
B. Blood culture
C. Seroconversion
D. Antibody production
Answer» D. Antibody production
31.

In the reaction, C6H12O6 + 6O2 → 6CO2 + 6H2O + energy, which component is being reduced?

A. O2
B. CO2
C. H2O
D. Energy
Answer» B. CO2
32.

For infection, skin and mucous membranes, acting as a

A. Chemical barrier
B. Physical barrier
C. Defenses
D. Immunity
Answer» C. Defenses
33.

The ability of CTP to bind to aspartate carbamoyltransferase and shut down the synthesis of more CTP is an example of

A. enzyme induction
B. enzyme repression
C. feedback inhibition of enzyme activity
D. none of these
Answer» D. none of these
34.

Treatment with bacterial endotoxins results blast formation in

A. B cells
B. T cells
C. monocytes
D. none of these
Answer» B. T cells
35.

Drug used against 'chronic active hepatitis' is

A. Abacavir
B. Tenofovir
C. Adefovir
D. Efavirenz
Answer» D. Efavirenz
36.

Major Histo Compatibility Complex (MHC) is a collection of genes arrayed on

A. chromosome 21 in man, chromosome 6 in mice
B. chromosome 6 in man, chromosone 21 in mice
C. chromosome 17in man, chromosome 6 in mice
D. chromosome 6 in man, chromosome 17 in mice
Answer» E.
37.

Which of the following theory of antibody production is most widely accepted?

A. Side chain theory
B. Clonal selection theory
C. Direct template theory
D. Indirect template theory
Answer» C. Direct template theory
38.

Oxidation is the

A. loss of proton
B. gain of electron
C. loss of electron
D. gain of protons
Answer» D. gain of protons
39.

Which is not a function of IgA?

A. Protect mucosal surfaces
B. Fix complement
C. Protect eyes
D. Agglutinate antigen
Answer» C. Protect eyes
40.

The secretary component of sIgA is

A. made by plasma cells that secrete dimeric IgA
B. added to dimeric IgA by the M cell
C. formed by cleavage of an epithelial cell receptor used to transport the dimeric IgA across the epithelial cell
D. made by T cells
Answer» D. made by T cells
41.

Main side effect of drug 'didoxyinosine' is

A. Pancreatitis
B. Peripheral neuropathy
C. None of These
D. Both a and b
Answer» E.
42.

Simulation of which of the following will lead to appearance of first antibody to appear following stimulation by an antigen?

A. IgM
B. IgA
C. IgE
D. IgG
Answer» B. IgA
43.

CD8 surface antigen is present in

A. cytotoxic T cells
B. suppresssor T cells
C. both (a) and (b)
D. none of these
Answer» D. none of these
44.

'Staphylococcus aureus' is mostly isolated from

A. Urine culture
B. Blood culture
C. Sputum culture
D. Throat culture
Answer» C. Sputum culture
45.

About 7.3 kcal/mole are released when

A. glucose is converted to CO2 and H2O
B. NAD+ is reduced to NADH
C. ATP hydrolysis is coupled to sucrose synthesis
D. the terminal phosphate bond of ATP is broken by hydrolysis
Answer» B. NAD+ is reduced to NADH
46.

'Ziagen' is a drug that is also called as

A. Abacavir
B. Tenofovir
C. Delavirdine
D. Efavirenz
Answer» B. Tenofovir
47.

Ganciclovir' has a structure that is similar to

A. Amantadine
B. Acyclovir
C. Selzentry
D. Vidarabine
Answer» C. Selzentry
48.

In the reaction, C6H12O6+ 6O2 → 6CO2 + 6H2O + energy, which component is being oxidized?

A. C6H12O6
B. O2
C. CO2
D. H2O
Answer» B. O2
49.

Adenosine triphosphate is a type of

A. fatty acid
B. amino acid
C. nucleotide
D. steroid
Answer» D. steroid
50.

Which of the following is the best evidence for the lock and key theory of enzyme action?

A. Compounds similar in structure to the substrate inhibit enzyme activity
B. Enzymes are found in living organisms and speed up certain reactions
C. Enzymes speed up reactions by definite amounts
D. Enzymes determine the direction of a reaction
Answer» B. Enzymes are found in living organisms and speed up certain reactions