Across
- 3. A process where cells engulf and digest pathogens using enzymes.
- 5. membrane Membrane that lines the digestive tract and respiratory tract.
- 7. Foreign substance that comes from outside the body and induces the production of antibodies.
Down
- 1. A protein produced by white blood cells into the bloodstream in response to antigens.
- 2. Secreted by the skin contain chemicals that can kill microorganisms.
- 4. Ability for the body system to resist pathogens before it is infected.
- 6. Made of a tough layer and difficult to be penetrated by microorganism