Which of the following traits in humans is controlled by the combined effect of more than one gene?

In human beings,multiple genes are involved in the inheritance of

Choose the possible genotype responsible for lightest skin colour in human beings.

$A$ polygenic trait is controlled by $3$ genes $A, B$,and $C$. In a cross $AaBbCc \times AaBbCc$,the phenotypic ratio of the offspring is observed as $1:6:x:20:x:6:1$. What is the possible value of $x$?

In the context of human skin color,which is controlled by polygenic inheritance,what phenotype is produced by the dominant homozygous condition (e.g.,$AABBCC$)?

Explain the effect of cumulative genes on skin color.