| 1. | B cells | 2. | interleukin-2 |
| 3. | interleukin-1 | 4. | histamines |
| Assertion(A): | Second infection of the same pathogen is quickly eliminated. |
| Reason(R): | Killer T cells becomes hyperactivated, and destroy extracellular pathogens |
| 1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
| 2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
| 3. | (A) is true but (R) is false. |
| 4. | Both (A) and (R) are false. |
| 1. | B cells confer active immunity; cytotoxic T cells confer passive immunity |
| 2. | B cells kill viruses directly; cytotoxic T cells kill virus infected cells. |
| 3. | B cells secrete antibodies against a virus; cytotoxic T cells kill virus-infected cells |
| 4. | B cell accomplish humoral immunity. |
| 1. | Variable Region – determines antibody specificity for an epitope |
| 2. | Immunioglobulins – glycoproteins that form epitopes |
| 3. | Constant Region – determines class and function of antibody |
| 4. | IgG – most abundant circulating antibodies, confer passive immunity to fetus |
| 1. | Excessive cell proliferation |
| 2. | Transformation of benign tumors into malignant tumors |
| 3. | Movement of cancerous cell from one site to another site of the body |
| 4. | Transformation of a normal cell into a tumorous cell |