1. Lack of reaction to our own human leukocyte antigens (HLAs) is known as?

A. autoimmunity
B. complement system
C. clonal selection
D. tolerance

2. Which of the following components of the vertebrate immune response occurs first upon invasion by a virus or bacterium?

A. Activation of killer T lymphocytes
B. Activation of B lymphocytes
C. The inflammatory response
D. Mobilization of complement proteins

3. Which of the following white blood cells act as scavengers when they engulf and digest pathogens?

A. Macrophages
B. T cells
C. B cells
D. Lymphocytes

4. A cell which defends against body cells in which viruses are reproducing is

A. Exotoxin
B. Cytotoxic T cell
C. Endotoxin
D. Suppressor T cell

5. Which of the following is most likely to produce anaphylaxis in a susceptible individual?

A. Pollen
B. Mold
C. Dust
D. Bee sting