Answer:
genes and the environment
Step-by-step explanation:
The traits that an organism have are affected by genes as well as environment.
Some of the phenotypic variances in individuals of a population are because of genotypic difference amongst them which is known as genetic variance and represented by (Vg).
Some of the differences in phenotypes are because of environment so it is known as environmental variance and represented by Ve.
But, if the effect of a gene depends upon a specific environment in which it is found then it is termed as genetic environmental interaction variance and represented by Vge.
So, the total phenotypic variance of traits is represented by the formula mentioned below:
Vp = Vg + Ve + Vge
Hence, genes and environment have cumulative effect on traits.