Answer:
A polygenic trait is controlled by multiple alleles.
Step-by-step explanation:
The phenotypic effect of a particular trait is controlled by multiple genes are known as polygenic traits. The environment can also effect the polygenic trait.
The example of polygenic trait in humans is height, hair color and skin color. These traits are controlled by more than two genes. Skin color is controlled by six multiple alleles in humans.
Thus, the correct term is multiple alleles.