Carrie's parents have brown hair. however, carrie gets genes for blond hair from both of her parents, and as a result she has blonde hair. this indicates that the gene for blonde hair is a:

She received the recessive allele.

Recessive allele

Explanation:

The alternative forms of that are present for a given gene are known as alleles.Two types of alleles exist for any given gene - these are dominant allele and recessive allele.A dominant allele is the one which always expresses itself in the presence of another allele, that is it can express itself in both heterozygous and homozygous situation.A recessive allele is only able to express itself in a homozygous condition.Since the blond hair is not expressing itself in either the mother or father but only in the daughter, it must be a recessive allele.