1. The thymus is where T-cell lymphocytes:

2. Phagocytosis takes place in:

3. Cytokines are chemical messengers which:

4. Lymphoid organs include the

5. One purpose of lymph nodes is to:

6. The majority of lymph fluid in the body returns to the venous circulation via the

7. Which of the following is an example of naturally acquired active immunity?

8. A role of immunoglobulin G (IgG) is to:

9. B-cell lymphocytes mature in the:

10. Which of the following are characteristics of free macrophages and microphages?