Question

1. What cell type makes sure that antibodies produced against microorganisms will target structures on the surface of the microorganism?

a. Helper T cells

b. Macrophages

c. B cells

d. Killer T cells

2. If a macrophage is infected a virus, viral peptides would be presented on

a. CD4 cell receptor

b. MHC class I

c. CD8 receptor

d. MHC class II

3. Which of the following proteins ensure that the immune system not attack our own cells:

a. MHC-II and CD47

b. CD8 T cell receptors and MHC-I

c. CD4 T cell receptors and MHC-II

d. MHC-I and CD47

e. MHC-I and MHC-II

Answer 1

1. Answer- B cells

Explanation - B cells only produce antibodies against one epitope present on the antigen. Epitope is the part or structure of antigen which gets recognised by the immune system of our body.

2. Answer- MHC class I

Explanation - viral peptides are present by MHC class I on the surface of infected cell to be recognised by the immune system. Macrophage also presents exogenous antigens on MHC I molecules through different pathway involving the internalization of antigen.

3. Answer - CD4 Tcell receptors and MHC II.

Explanation - CD4 T helper cells are mainly involved in immune tolerance mechanism and give confirmatory signal to B cells before they start producing antibodies. Prevention of immune system to not attact our own cells is called self tolerance or immune tolerance.