A Geneticist is a scientist with a focus on the study of genetics. Geneticists study the impact genes have on health and disease and focus on the research and altering of genetic makeup. Geneticists can work in a variety of different fields; however, the three majors fields include agriculture, crime, and medicine. Within these different fields, Geneticists work on tasks like uncovering the origin of birth defects, finding ways to treat disease, and matching DNA with a person who is convicted of a crime.