The term gene refers to a fundamental unit of heredity, whereas the term characteristic refers to the outward expression of the information contained within these fundamental units of heredity. Chemically, genes are composed of genetic information in the form of specific sequences of DNA (deoxyribonucleic acid). Through a complex and elaborate biochemical process, the information within these genes is expressed in the form of proteins. One or more genes may code for a variety of proteins which play a role in the creation of a particular characteristic. Consider Sickle Cell Anemia. A mutation or collection of mutations within genes which code for a protein found within red blood cells (e.g., hemoglobin) can result in significantly impacting on one or more characteristics of red blood cells (e.g., the sickled shape of the red blood cell) thereby leading to Sickle Cell Anemia.