Blonde hair (b) is recessive, and brown hair (B) is dominant.
A parent has brown hair (Bb). Their first child has blonde hair (bb). Their second child has brown hair (BB).
What must the other parent have (hair color and allele combination)?
(1 point)
O Bb, brown hair
Bb, blonde hair
O. BB, brown hair
O bb, blonde hair
Pick the correct answer
The other parent must have bb, blonde hair.
The other parent must have brown hair and carry the recessive allele for blonde hair. Therefore, the correct answer is O Bb, brown hair.
To determine the other parent's hair color and allele combination, we can look at the children's hair colors. The first child has blonde hair (bb), indicating that both parents must contribute the recessive blonde hair allele. The second child has brown hair (BB), which means they received the dominant brown hair allele from at least one parent.
Since the first child has blonde hair (bb), we know that the parent in question must have the blonde hair allele (b). However, since the second child has brown hair (BB), we also know that the parent in question must have contributed the dominant brown hair allele (B).
Therefore, the correct answer is "Bb, blonde hair."