Account for the hereditary influence on the phenotype in a cumulative way.

Additive alleles

Explanation:

Additive alleles account for the hereditary influence on the phenotype in a cumulative way.

Alleles are nothing but variations of a gene. that simply gives variation to the traits.

Whereas, Additive alleles are alleles that contribute to most observable traits, such as height, weight, hair color, eye color,and complexion. Therefore, they account for the hereditary influence on the phenotype.