What do the genes responsible for skin color indicate?

Inheritance of skin colour in humans is an example of

An example of polygenic inheritance in humans is .....

Explain the effect of cumulative genes on skin color.

In a dihybrid cross,instead of a $9:3:3:1$ ratio,a $1:4:6:4:1$ ratio is obtained. This is an example of .....

The kernel color of wheat is determined by three pairs of polygenes. In a cross between $AABBCC$ (dark color) and $aabbcc$ (light color),what will be the proportion of $F_2$ progeny having a kernel color similar to either of the two parents?