These features are controlled by a single gene that is either dominant or recessive. When the dominant gene is paired with the recessive gene the dominant trait is exhibited. Hair color, hair curliness, and lip color are traits that exhibit incomplete dominance. When two different forms of the gene are combined, a third intermediate type results. For example, when black hair is crossed with blonde hair the result might be brown hair.
Eye color is controlled by multiple genes.
This model uses two genes, one that determines brown pigment and a second that determines yellow pigment, which combine to determine the final eye color. Each camper needs a face outline, facial features worksheet, two pennies, and coloring tools. Flip the two pennies to determine the combination of genes the this imaginary person inherits from its parents. After each set of coin flips, circle the appropriate type on the worksheet. When all the traits have been determined, have campers use the face outline to draw a picture of each imaginary person.