The ability to roll the tongue is caused by a dominant allele. A woman is a "roller," but one of her parents is not. What is the woman's genotype?
A) homozygous dominant
B) heterozygous
C) homozygous recessive
D) either homozygous recessive or homozygous dominant
E) It cannot be determined from this information.

Question

Quizplus · Accepted Answer

The woman must be heterozygous because she is a roller (has the dominant trait) but has a non-roller parent (who must be homozygous recessive). Therefore, she must have inherited one dominant allele from the roller parent and one recessive allele from the non-roller parent.

The Ability to Roll the Tongue Is Caused by a Dominant