Moles occur when cells in the skin grow in a cluster instead of being spread throughout the skin. These cells are called melanocytes, and they make the pigment that gives skin its natural color. Moles may darken after exposure to the sun, during the teen years, and during pregnancy.
A pedigree chart is used to show your family tree of traits. An example is if a diagram shows your mom who had brown hair and your dad has red hair and then it shows all of th â¦ e children they had and shows what color hair they had.
In a pedigree chart, generations are represented by Roman numerals. Each person in each generation is numbered. Males are represented by a square and females by a circle. A horizontal line connecting a male and female is called a marriage line. Vertical lines represent children.