Question

Two smooth-faced parents with a dimple-cheeked baby show up one day in a small town. They integrate smoothly into the community, but one day their pediatrician calls a police hotline and reports them for kidnapping. They are stunned that their crime was uncovered, until their attorney explains that the dimples gave them away: it is genetically unlikely for smooth-faced parents to have dimple-faced offspring. To demonstrate this, he fills out a Punnett square. What is the genotype or genotypes of the "parents"?

Answer 1

Answer:

See the answer below

Explanation:

Dimple cheek is usually considered to be an autosomal dominant trait, meaning that only one dominant allele is needed for the trait to physically manifest itself in individuals.

Assuming that the allele for dimple cheek is represented by D. Since the two parents are dimple-cheeked, their genotype could be DD/DD or DD/Dd. In each case, the Punnet square analysis of their likely offspring is shown in the attached images.

                           DD   x   DD

offspring:     DD   DD   DD   DD (all dimple-cheeked)

                          DD   x   Dd

offspring:        DD   Dd   DD  Dd (all dimple cheeked)