Exoskeleton - An external skeleton that protects and supports an organism, in contrast to an internal endoskeleton.⏎
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.⏎
Evolution - The change in heritable traits in a population of organisms over successive generations.⏎
Endemic - The baseline level of disease usually present in a community.⏎
Gastrointestinal Tract - The structure in the body, beginning with the mouth and extending to the anus, through which food is ingested, broken down, and absorbed to provide the body with nutrients, and waste products are excreted.⏎