The color white deflects heat and the color black absorbs heat. You don't see the color something is, the see the color something is not( if something is red, then it absorbs all colors but the color red, and the red is instead reflected into your eyes). White is all the colors, meaning that the chalk deflects all colors/light. light is heat so it also deflects heat, making it so that the heat goes away.
A dihybrid cross involves such a cross where the inheritance of two different traits is simultaneously observed.
The genotypes and the corresponding phenotypes obtained with respect to individual trait in the F1 and the F2 generations of the cross will help to determine whether the inheritance pattern of one trait is affected by the other or not.
The genotype and the phenotype ratio is determined to understand the dependence of one trait over the other.
