| A | B |
|---|
| Pathogens | Microorganisms which cause disease |
| Interface | A surface or boundary linking two systems |
| gas exchange system | Respiratory tract surfaces |
| digestive system | digestive tract surfaces |
| toxins | poisons |
| transmission | Spreading from one individual to others |
| prokaryotic | has no nucleus |
| eukaryotic | has a nucleus |
| communicable | can be caught by infection |
| non-communicable | can't be caught by infection |
| disorders | non-communicable diseases |
| degenerative | diseases where systems break down due to age or overuse |
