The principle of immunization or vaccination is based on which property of the immune system?
| 1. | Specificity |
| 2. | Memory |
| 3. | Ability to recognize self from non-self |
| 4. | Cooperation between innate and adaptive immunity |
Small masses of lymphatic tissue found throughout the ileum region of the small intestine are called:
| 1. | Paneth cells | 2. | Meissener’s Plexus |
| 3. | Peyer’s patches | 4. | Entero-chromaffin cells |
What constitutes about 50% of the lymphoid tissue in the human body?
| 1. | Malt | 2. | Spleen |
| 3. | Lymph nodes | 4. | Liver |