Plasmid - A ring of DNA usually found in bacteria that is separate from and can replicate independently from DNA in a chromosome and can provide bacteria with some advantages, such as antibiotic resistance.⏎
Pandemic - An increase in the occurrence of a particular disease over a very large region, such as a continent or the entire globe, that is greater than what is expected over a given period of time.⏎
Prion - A causative agent of infectious disease that is composed primarily of protein.⏎
Reservoir - An organism in which a parasite that is pathogenic for some other organism lives and reproduces without harming its host.⏎
Peptic Ulcer - An open sore that develops on the inner lining of the stomach or upper small intestine.⏎