How do we know that height in humans is a polygenic trait and not a single-gene
trait?

A. There is no way to know for sure.

B. People have varying heights.

C. Height is too complex to be controlled by a single gene.

Error analysis: what might be the reason that some of your percentages didn't exactly match your predicted results? gametes aren't responsible for inheritance. mice don't have large litters, so the sample size was not large enough. the wrong type of mice were used.