The presence of two different alleles resulting in an intermediate phenotype is called incomplete dominance.

Here's a breakdown:

* Alleles: Alternative forms of a gene.

* Incomplete Dominance: A pattern of inheritance where neither allele is completely dominant over the other. The heterozygous genotype results in a phenotype that is a blend or mix of the two homozygous phenotypes.

Example:

* Flower color in snapdragons: A red flower (RR) crossed with a white flower (WW) produces pink flowers (RW). The pink flowers are a blend of the red and white phenotypes, demonstrating incomplete dominance.