Why do we fall ill

4. Most abundant cells of the immune system
5. A sticky thick fluid secreted by our glands which acts as a barrier against invaders
7. A disease spread by bacteria in the air
10. Another name for Bubonic plague caused by Yersinia pestis
13. A fundamental type of response by the body to disease and injury

1. Causes Measles
2. An organism found in he stomach of about 50% of all humans
3. Neutrophils engulf the invaders through this process
6. Carrier of a pathogen
8. Bacteria that cause acne
9. A disease that is also known as break-bone fever due to excess pain in the bones
11. The protective ability of our body
12. A disease caused by protozoan parasite which bursts the blood cells
14. A micro-organism that usually causes infection in our skin or stomach