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. ⏎
Protein - Large molecules composed of one or more chains of amino acids in a specific order determined by the base sequence of nucleotides in the DNA coding.⏎
Natural Selection - The process by which certain heritable traits that contribute to the survival and reproductive success of an organism become more widespread within a population over successive generations.⏎
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.⏎