Contagion - A general term for any disease-causing infectious agent spread by direct or indirect contact.⏎
DNA - Short for deoxyribonucleic acid, DNA is any of the nucleic acids that contain the genetic instructions necessary for the development and functioning of all living organisms as well as some viruses.⏎
Ecology - A branch of science that deals with the relation of organisms to one another and their physical environment.⏎
Gene - The physical and functional unit of heredity made up of DNA. Every individual has two copies of each gene, one inherited from the mother and the other from the father.⏎