Source: Pedigree chart, Public Domain: http://en.wikipedia.org/wiki/File:Pedigree-chart-example.png
A genetic characteristic that causes health problems (example: Huntingtons Disease).
A genetic characteristic that is not typical (example: 6 toes).
An individual who is carrying a trait genotypically but does not display it phenotypically.
A chart used to track a trait through a family tree.