So for example, if in a given individual all of these genes contain the uppercase letter, so these are uppercase A, these are uppercase B and these are uppercase C, then we have uppercase AA, uppercase BB, uppercase CC. And this represents the darkest possible skin color and likewise if all of these are lowercase letters so lowercase A, lowercase A, lowercase B, lowercase B, lowercase lowercase C, lowercase C then we have the lightest possible skin color. Now to further demonstrate how this added effect in polygenic inheritance actually works, let's carry out the following experiment. Let's suppose we have a male individual that contains this genotype. So we have these three pairs of homologous chromosomes and on each one of these individual chromosomes we only have uppercase letters. So we have uppercase A, uppercase A on this set of alleles we have uppercase B, uppercase B on the second set of alleles and uppercase C, uppercase C and let's suppose we mate this male individual with the female that is homozygous recessive for all of these different genes.