What are the three classes of lymphocytes, and where does each class originate?

A decrease in which population of lymphocytes would impair all aspects of an immune response?

(a) Cytotoxic T cells

(b) Helper T cells

(c) Regulatory T cells

(d) B cells

(e) Plasma cells

Perforins are proteins associated with the activity of

(a) T cells

(b) B cells

(c) NK cells

(d) Plasma cells

Where do T cells undergo central tolerance selection?

Explain why a patient with AIDS due to HIV is at an increased risk of infection and of developing certain cancers.

Mark the following statements as true or false. If a statement is false, correct is to make a true statement.

The secondary immune response is mediated by plasma cells.