Across
- 2. The part of the antibody that stays the same and helps signal other immune cells.
- 3. A Y-shaped protein made by the body to stick to and help destroy harmful invaders.
- 5. A shape that fits perfectly with another, like a key fits a lock.
- 6. The part of the antibody that changes to match different antigens.
Down
- 1. The part at the tips of the antibody that sticks exactly to the antigen.
- 3. A foreign substance (like a virus or bacteria part) that causes an immune response.
- 4. A type of white blood cell that makes antibodies.