Skin colour is controlled by three genes; A,B,C dominant genes and a,b,c the recessive genes ; the effect of each type of allele is addictive ; more the dominant allele, darker the skin colour; more the recessive allele lighter the skin colour ; when three dominant alleles and three recessive alleles
are present in an individual the skin colour is intermediate
- Polygenic inheritance
- Human Height /or any other correct example