(12.1) PDF 1 - Animal and Plant pathogens (12.2) PDF 2 - Animal and Plant diseases (12.3) PDF 3 - The transmission of communicable diseases (12.4) PDF 4 - Plant defences against pathogens (12.5) PDF 5 - Non-specific plant defences against pathogens (12.6) PDF 6 - The specific immune system (12.7) PDF 7 - Preventing and treating disease