Topography is the rise and fall of the land (AKA B)
We know that height in humans is a polygenic trait because it has a lot of variation. The height gene is controlled by at minimum three genes with six different alleles. If all of these alleles are dominant for the tall gene you will be tall if you are dominant for the short gene you will be short if there is no clear dominance between the two genes you will fall somewhere in the middle.
