Question

1. Indicate which of the following characteristics does not apply to T_Reg cells

1. Modulate the function of antigen presenting cells by blocking B7
2. Have cytolytic effect on effector cells.
3. Inhibit activation and proliferation of effector cells by releasing inhibitory cytokines
4. Induce expression of pro-apoptotic proteins on T cells
5. Express low levels of CTLA-4

2. Which statement is correct?

1. Basophils do not have phagocytic activity
2. The myeloid progenitor cell divides and differentiates to produce at least six different cell types
3. Neutrophil, eosinophil, and basophils are the three types of granulocytes
4. Mast cells have high affinity receptors for IgE antibodies
5. All of the above

3. At what stage of development does a B cell begin to express a pre-B-cell receptor?

1. Large Pre B cell
2. Early pro-B cell
3. Late pro-B cell
4. Small pre-B cell
5. Immature B cell

4. What statement is true

1. All immunogens are antigens
2. The most important function of antibodies is to facilitate the engulfment and destruction of extracellular microorganisms and toxins by phagocytes.
3. All antigens are immunogens
4. Immunogens are antigens that cannot trigger an immune response
5. Antibodies bind to pathogens through the Fc portion of the molecule
6. A and B
7. A, B, and E

5. Which of the following pairs is mismatched?

A. lymphocytes: innate immune response

2. natural killer cell: kills virus-infected cells
3. macrophage: phagocytosis and killing of microorganisms
4. erythrocyte: oxygen transport
5. eosinophil: defense against parasites.

Answer 1

1) Answer : Option (E) Express low levels of CTLA-4

Explanation : Regulatory T cells express high levels of CTLA4

2) Answer : Option (E) All of the above

Explanation : Basophils have insignificant phagocytic acitivity, the myeloid progenitor cell divides and differentiates to produce at least six different cell types like leukocytes, erythrocytes, neutrophil, eosinophil, and basophils are the three types of granulocytes, mast cells have high affinity receptors for IgE antibodies

3) Answer : Option (A) Large pre B cell

Explanation : At  large pre B cell stage, B cell begin to express a pre-B-cell receptor

4) Answer : Option (A) All immunogens are antigens.

Explanation : All immunogens are antigens but all antigens are not immunogens.

5) Answer : Option (A)

Explanation : Lymphocytes are a part of adaptive immune system and not an innate immune system