In humans,having dimples in the cheeks is a dominant trait.If a child has dimples but only one of her parents does,what are the genotypes of her parents? (D = dimples;d = no dimples)
A)One parent dd,other parent DD
B)One parent dd,other parent Dd
C)One parent Dd,other parent DD
D)One parent must be DD,the other parent could be either dd or Dd
E)One parent must be dd,the other parent could be either Dd or DD

Question

Quizplus · Accepted Answer

In order for the child to have dimples (D), they must have at least one dominant allele from one parent. If only one parent has dimples, then that parent must be heterozygous (Dd), meaning they carry one dominant allele and one recessive allele. The other parent must then be homozygous recessive (dd), meaning they carry two copies of the recessive allele. Therefore, the possible genotypes for the parents are dd and Dd, making choice E the best answer.

In Humans,having Dimples in the Cheeks Is a Dominant Trait