Who is a person who has one recessive allele for a trait and one dominant allele for the same trait?

Answer: The person is heterozygous for the trait. The person is a carrier of the recessive allele of the trait.

Explanation: Take for instance the height trait. If H is a dominant allele for tall height and h is recessive allele for short height, a person who has one recessive allele and one dominant allele will have a genotype of Hh, this means that the person is heterozygous for the trait. In this example, the genotype Hh will manifest outwardly as tall height because H is dominant over h.