KA – Viruses
https://www.khanacademy.org/science/biology/biology-of-viruses/virus-biology/v/viruses
Animal Virus Information Page
http://faculty.ccbcmd.edu/courses/bio141/lecguide/unit4/viruses/prodlc.html
Flu attack
https://www.youtube.com/watch?v=Rpj0emEGShQ
1918 Spanish Flu
https://www.youtube.com/results?search_query=spanish+flu
KA subviral particles (prions and viriods)