Pathogens - organisms that cause disease

pathogen image - http://ib.bioninja.com.au/standard-level/topic-6-human-physiology/63-defence-against-infectio/pathogens.html bacteria image - https://www.freepik.com/free-photos-vectors/bacteria virus image - https://www.freepik.com/free-photos-vectors/virus parasite image - https://www.thespruce.com/can-tapeworms-live-outside-body-2804980 fungi image - http://www.regionalderm.com/Regional_Derm/files/tinea_bullous.html