Question

Brown eye-color alleles are dominant over blue eye-color alleles, which are recessive. jenna has brown eyes. her husband, bill, has blue eyes. jenna and bill are the biological parents of james, who has blue eyes. what eye-color gene alleles must jenna have?
c. bb (two blue alleles)
b. bb (two brown alleles)
a. bb (one brown and one blue allele)
d. bbb (three brown alleles)

Answer 1

Brown eye-color is dominant while the blue-eye color is recessive. Therefore, the homozygous for brown color is BB and the homozygous for brown color is bb. Thus, the heterozygous will be Bb (brown color). Since James has blue colored eyes  a child of Jenna (brown color) and bill (blue color) then it means Jenna is heterozygous (Bb). Jenna is described  as being a carrier of the allele for blue eyes.