Explore topic-wise MCQs in Microbiology.

This section includes 24 Mcqs, each offering curated multiple-choice questions to sharpen your Microbiology knowledge and support exam preparation. Choose a topic below to get started.

1.

T cell receptors (or TCR) on CD4+ T cells

A. recognize peptides not associated with MHC molecules
B. recognize peptides associated with MHC class I molecules
C. recognize peptides associated with MHC class II molecules
D. are secreted out into the environment to bind antigens
Answer» D. are secreted out into the environment to bind antigens
Discussion
2.

Large parasites such as helminthes may be killed extracellularly by the action of
A. basophils
B. monocytes
C. eosinophils
D. neutrophils
Answer» D. neutrophils
Discussion
3.

Lysozyme is present in
A. sweat
B. Cerebro spinal fluid (CSF)
C. urine
D. saliva
Answer» E.
Discussion
4.

Which of the following proteins would not need localization signal?
A. A nuclear protein
B. A cytosolic protein
C. A protein bound to the endoplasmic reticulum (ER) membrane
D. A cell surface protein
Answer» C. A protein bound to the endoplasmic reticulum (ER) membrane
Discussion
5.

The role of the M cell is to
A. trap virus in mucus and prevent entry
B. induce apoptosis in virus-infected small intestinal epithelia cells
C. pass bacteria or virus to underlying macrophages for processing and presentation of antigen
D. they use their cilia to propel mucus out of the small intestine
Answer» D. they use their cilia to propel mucus out of the small intestine
Discussion
6.

Which of the following statements is false regarding B cells?
A. B cells can undergo class switching and produce a different antibody type
B. B one marrow stem cells migrate to the thymus and develop into B cells
C. B cells synthesize antibodies and put them on their cell surface
D. B cells that recognize high concentrations of antigens (self) in the absence of other signals undergo apoptosis in the bone marrow
Answer» C. B cells synthesize antibodies and put them on their cell surface
Discussion
7.

Following are the defenses of the colon except
A. sIgA
B. fast flow rate
C. dense resident microbiota
D. mucus
Answer» C. dense resident microbiota
Discussion
8.

Natural killer cells are involved in
A. tumour rejection
B. allograft rejection
C. non-specific killing of virus transformed target cells
D. all of these
Answer» E.
Discussion
9.

Which of the following(s) is/are the determinants of antigenicity?
A. Chemical nature
B. Size of the antigen
C. Foreignness
D. All of these
Answer» E.
Discussion
10.

Immunity is not long lasting to
A. influenza
B. whooping cough
C. diphtheria
D. mumps
Answer» B. whooping cough
Discussion
11.

Cytotoxic T-cells can be recognized by which of the following cell surface marker?
A. CD4
B. CD7
C. CD8
D. CD9
Answer» D. CD9
Discussion
12.

Which is not an antigen-presenting cell (or APC)?
A. B cell
B. Polymorphonuclear leukocyte (or PMN)
C. Dendritic cell
D. All of the above
Answer» C. Dendritic cell
Discussion
13.

Chemically an antigen may be
A. lipid
B. protein
C. polysaccharide
D. any of these
Answer» E.
Discussion
14.

Which of the following expresses CD3 surface antigen?
A. Granulocytes
B. T cells
C. Monocytes
D. B cells
Answer» C. Monocytes
Discussion
15.

Polymorphonuclear leukocytes (or PMNs)
A. can be attracted to the site of an infection following activation of complement
B. are derived from bone marrow stem cells
C. are a type of phagocyte that can engulf and kill bacteria
D. all of the above
Answer» E.
Discussion
16.

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.
Discussion
17.

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
Discussion
18.

Treatment with bacterial endotoxins results blast formation in
A. B cells
B. T cells
C. monocytes
D. none of these
Answer» B. T cells
Discussion
19.

Passive immunization is done for
A. tuberculosis
B. diphtheria
C. enteric fever
D. all of these
Answer» C. enteric fever
Discussion
20.

Which of the following is correct for isoantigens?
A. They are antigens found in all members of different species
B. They are antigens found in some members of a species
C. They are antigens found in all members of a species
D. They are antigens found in some members of different species
Answer» C. They are antigens found in all members of a species
Discussion
21.

Numerous antibodies can be prepared, against one antigen, each binds to unique epitopes. How is this antibody diversity generated?
A. By rearrangements of the DNA encoding the variable regions of the heavy and light chains
B. By the combination of different heavy and light chains that form the antigen binding site
C. Antibody proteins can physically change their shape to bind different epitopes
D. Both (a) and (b)
Answer» E.
Discussion
22.

Which of the following is correct for CD8 T cells?
A. CD8 T cells only recognize virus-infected cells
B. CD8 T cell receptor recognizes epitopes that are also commonly recognized by B cells
C. In the thymus, CD8 T cells undergo positive selection only, whereas CD4 T cells undergo negative selection only
D. CD8 T cells can kill individual virus-infected cells in a contact dependent fashion
Answer» E.
Discussion
23.

Macrophages are professional antigen- presenting cells. The protein molecule through which they present antigen in human is
A. actin
B. interleukin
C. HLA
D. CD8
Answer» E.
Discussion
24.

T cell receptors (or TCR) on CD4+ T cells
A. recognize peptides not associated with MHC molecules
B. recognize peptides associated with MHC class I molecules
C. recognize peptides associated with MHC class II molecules
D. are secreted out into the environment to bind antigens
Answer» D. are secreted out into the environment to bind antigens
Discussion