Exoskeleton - An external skeleton that protects and supports an organism, in contrast to an internal endoskeleton.⏎
Ecology - A branch of science that deals with the relation of organisms to one another and their physical environment.⏎
Disease - Any abnormal condition that affects all or part of an organism, resulting in symptoms such as pain or loss of function.⏎
Epidemic - An often sudden increase in the level of disease in a specific population over a given period of time.⏎
Genetics - A branch of biology that studies heredity and variation in organisms.⏎