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.⏎
Exoskeleton - An external skeleton that protects and supports an organism, in contrast to an internal endoskeleton.⏎
Ecosystem - A functional unit that consists of all the living organisms in a particular area, as well as the nonliving, physical components in the environment—such as air, soil, water, and sunlight—with which the organisms interact, and how natural and human-made changes affect these interactions.⏎
Cirrhosis - A condition caused by chronic liver disease characterized by the development of scar tissue leading to a loss of liver function.⏎
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.⏎