Answer:
Multiple-factor inheritance
Step-by-step explanation:
Mutiple factor inheritance or genetic variation are variation that are controlled by few genes and many minor gene.
Traits controlled by cummulative effect of many genes contributing its bits are refer to as quantitative traits of character.
Multiple factor inheritance is a variation in which individual phenotypic difference cannot be divided into distinct classes either when controlled by many genes or few genes. Environment also contribute to this variation as phenotype=Genotype +Environmental.
Example of multiple factor is skin color