AP BIOLOGY

Detailed explanation-1: -A person that has cheek dimples will have a genotype of either DD (homozygous) or Dd (heterozygous). Both of these combinations of alleles will result in a child with dimples.

Detailed explanation-2: -The allele for dimples (D) is dominant to the allele for no dimples (d). A man heterozygous for dimples marries a woman who is also heterozygous for dimples. Offspring phenotypes: The allele for hitchhiker’s thumb (h) is recessive to straight thumb (H).

Detailed explanation-3: -Because the dimples trait is dominant, you only need to have a single copy of the dominant (D) allele to express the trait of dimples. All the children will have dimples since there is no chance of having an offspring with the homozygous recessive genotype (dd) and the no dimples phenotype.