Question

having no dimples is a recessive trait in humans that is controlled by a single gene. how many recessive alleles must a person have to have no dimples?
a. 3
b. 2
c. 0
d. 1

Explanation:

In genetics, for a recessive trait controlled by a single - gene, an individual must have two copies of the recessive allele to express the recessive phenotype. Since having no dimples is a recessive trait, a person needs two recessive alleles.

Answer:

B. 2