How do diseases affect the body - student led activity or class lesson and worksheet. Students are led through a discussion of how each disease and pathogen actually work in the body - the affects of viruses, bacteria, fungi, parasites, metabolic issues, congenital defects and cancers. Each section has short YouTube videos that can be used for individual research or shown and discussed as a whole class and then students are asked to discuss what it is, how it affects the body and research dise