Which allele is expressed in a heterozygous individual?

I'm pretty sure the recessive allele is expressed in a heterozygous individual.

Just letting u know tho, I'm not completely sure

Hope it is right and helps u tho...lemme know :)

The right answer is Dominant allele.

A dominant allele qualifies the allele that wins over the associated allele. When the genetic action takes place in complete dominance, the dominant allele totally eclipses the recessive allele at the heterozygous stage, whereas it only partially eclipses it when the genetic action is manifested in an incomplete dominance mode.

The dominant alleles are those that appear in the phenotype of individuals.

d. organisms have cells with different shapes and functions.

her affection for her parents makes her an especially sympathetic character.