Something Practical: What’s your allele?

Pick two of the traits below.  What is your phenotype for that trait?  Can you determine your genotype from your phenotype?  Why or why not?  If the answer is no, what additional information would you need to determine your genotype? 

Free Ear LobeThe allele for earlobes that hang “free” is dominant over earlobes that are attached directly to the side of the head.Widow’s PeakThe allele for the downward point in your hairline, known as the widow’s peak, is dominant over the allele for a straight hairline.Hitchhiker’s ThumbPeople with this dominant allele can bend their thumbs backward until the top of their thumb is almost horizontal. People with hitchhiker’s thumb have more flexible joints.Immunity to Poison IvyDespite worried Moms whose kids are going out for nature walks immunity to poison ivy is dominant, although it may not be common in a population.FrecklesIf you’re a freckle faced strawberry like Julianne Moore, your freckle gene is dominant.DimplesIf you have dimples like Shirley Temple, you inherited another dominant gene.