The ability to curl one's tongue into a U-shape is a genetic trait. Curlers always have at least one curler parent but noncurlers can have one or both parents who are curlers. Using C and c to symbolize the alleles that control this trait, what is the genotype of a noncurler?
A) CC
B) Cc
C) cc
D) CC or Cc

Question

Quizplus · Accepted Answer

A noncurler must have the genotype cc, as curling is a dominant trait and requires at least one dominant allele (C) to express the trait. Noncurlers, therefore, have two recessive alleles (cc).

The Ability to Curl One's Tongue into a U-Shape Is