Virology Multiple Choice Questions & Answers (MCQs) focuses on “Immunology of Virus”.
1. Which of the following protein recognizes MHC class I proteins?
a) CD4
b) CD8
c) CD26
d) CD10
Answer: b
Clarification: CD8 (Cluster of Differentiation) is an integral transmembrane glycoprotein present on the surface of T cells that recognizes MHC (Major Histocompatibility Complex) class I proteins.
2. Which of the following is a primary lymphoid organ?
a) Lymph
b) Spleen
c) MALT
d) Bone marrow
Answer: d
Clarification: Bone marrow is a primary lymphoid organ. It is an organ where lymphocytes (B & T) arise there. 90% of plasma antibodies come from B cells in the bone marrow.
3. T cells mature in ______________
a) bone marrow
b) thymus
c) spleen
d) lymph
Answer: b
Clarification: The maturation of T lymphocytes or T cells occurs in the thymus. The development or formation of T cells occurs in the bone marrow and then T cells travel through the bloodstream to the thymus and mature there. B cells mature in the bone marrow.
4. Hematopoiesis occurs in ______________
a) Thymus
b) Spleen
c) Bone marrow
d) MALT
Answer: c
Clarification: Hematopoiesis occurs in the bone marrow. Hematopoiesis is the process of formation of all the types of blood cells from hematopoietic stem cells (HSCs) present in the bone marrow.
5. Which of the following controls the release of hematopoietic cells from bone marrow?
a) Osteoblasts
b) Endothelial cells
c) Sympathetic neurons
d) Reticular cells
Answer: c
Clarification: Sympathetic neurons controls the release of hematopoietic cells from the bone marrow. The adult bone marrow contains several cell types that coordinate HSC development including, osteoblasts, endothelial cells, reticular cells, and sympathetic neurons.
6. Which of the following is not part of the mononuclear phagocyte system?
a) Mesangial cells
b) Endothelial cells
c) Kupffer cells
d) Macrophage
Answer: b
Clarification: Endothelial cells are not part of the mononuclear phagocyte system. The macrophages which line the medullary sinuses are part of the mononuclear phagocyte system. Mesangial cells of the kidney, Kupffer cells of the liver, etc. perform phagocytosis and kill the bacteria.
7. Which of the following cells form NET and perform phagocytosis?
a) Lymphocytes
b) Neutrophils
c) Basophils
d) Eosinophils
Answer: b
Clarification: Neutrophils are the granulocytes present in leukocytes that form NET (Neutrophil Extracellular Trap) and trap the microbes and kill them. Neutrophils are the first cells to arrive at the site of inflammation and form NET and perform phagocytosis.
8. Which of the following is not an APC cell?
a) Monocytes
b) Keratinocytes
c) Macrophages
d) Dendritic cells
Answer: b
Clarification: Keratinocytes are not the antigen-presenting cells (APCs). APCs are the cells that present antigens to B cells and T cells. Dendritic cells (DCs), monocytes, macrophages, B cells, etc. are antigen-presenting cells (APCs).
9. Which of the following is an abundant class of antibody in the serum?
a) IgE
b) IgD
c) IgA
d) IgG
Answer: d
Clarification: IgG is the most abundant antibody present in serum i.e. 80%. IgG plays an important role in the neutralization of toxins, providing immunity to newborns, etc.
10. IgM antibody exists as a pentamer.
a) True
b) False
Answer: a
Clarification: IgM antibody exists as a pentamer molecule with five IgM monomers linked at their C-termini. It protects against many viral and bacterial infections and is found in all body fluids.
11. Cytokines coordinate the immune system.
a) True
b) False
Answer: a
Clarification: Cytokines coordinate the immune system and are soluble proteins that are secreted by the specific cells of the immune system. Cytokines include interferons and interleukins which help to regulate the immune system.