Answer the following question given this paragraph: 

Some traits are controlled by more than one gene. They are called polygenic traits. Each gene for a polygenic trait may have two or more alleles. The genes may be on the same or different chromosomes. Polygenic traits may have many possible phenotypes. Skin color and adult height are examples of polygenic traits in humans. Think about all the variation in the heights of adults you know. Normal adults may range from less than 5 feet tall to more than 7 feet tall. There are people at every gradation of height in between these extremes.


Q: Polygenic traits are controlled by more than one of these?

 Choices:

- phenotypes

- chromosomes

- genomes

- genes

A:
genes
