Across
- 6. they are viruses caused by tiny invaders
- 9. helps protect us against disease
- 10. destroys cells that have been infected by the invaders
Down
- 1. use to help our immune system be ready for a certain sickness
- 2. these cells produce antibodies
- 3. when our bodies develop immunities over time through the immune system
- 4. when we are born, our bodies may already have some immunity
- 5. remember antigens that have attached the body before
- 7. scientist call the invaders that can cause disease________.
- 8. get rid of good cells that have been infected by the invaders