Draw a pedigree for this family, indicating the phenotype and expected genotype of each individual.

Question

Having face freckles is a dominant trait. A woman who has face freckles marries a man who does not. They have 4 children. The oldest, a girl, has face freckles, followed by a boy who does not have face freckles. Finally, there is a set of twin boys – one of the twins has face freckles. 

Answer 1

Great question, Danielle. Here's how you can answer that. First, make a key for how you will denote things in your pedigree. Usually, circles signify female and squares signify males, and filled in shapes signify someone having the tracked trait, while uncolored shapes signify not having the trait.

Color in the female who has freckles' circle, while leaving her male, unfreckled partner's square uncolored. Draw a horizontal line between them. Draw a vertical line down, then a horizontal line, with all of the children below the horizontal line. For each that has freckles, fill in their shape, while those that don't should have their shapes left unfilled.

Hope this helps!