Organism - A living being that can reproduce, grow, react to external stimuli, and maintain its internal equilibrium.⏎
Protozoa - A taxonomic group of single-celled microorganisms that live in almost every kind of habitat and include some pathogenic parasites of humans and other animals. ⏎
Nanometer - A unit of length equal to one one-billionth (1 x 10-9) of a meter.⏎
Outbreak - An unexpected increase in the incidence of a particular disease over a given time period and geographic range. A general term that may refer either to an epidemic or a pandemic.⏎
Prion - A causative agent of infectious disease that is composed primarily of protein.⏎