Answer:
Polygenetic inheritance
Explanation
Polygenetic inheritance also called Multifactorial inheritance it occurs when a single characteristic is controlled by more than two genes .
An example is the human skin pigmentation which is determined by the amount of melanin it contains.
Melanin production involves at least four genes. A combination of of melanin producing allele determines the degree of pigmentation.
This shows each gene has exerted a small addictive effect in determining the trait.
