Question

what do genetics call alleles that are both expressed in the phenotype when they are together

Answer 1

co-dominant alleles, in other words because they both appear in the phenotype they are both dominant.

Answer 2

The correct answer is:

codominance

Explanation:

Codominance is a kind of dominance wherein the alleles of a gene set in a heterozygote are fully represented. This results in offspring with a phenotype that is not dominant nor recessive. A typical example telling codominance is the ABO blood group system.