In polygenic inheritance,

Question $29$ options:

A$)$

phenotypic characteristics are determined by a single pair of alleles.

B$)$

phenotypic characteristics are determined by the genes on the Y chromosome.

C$)$

phenotypic characteristics are determined by the action of a single gene.

D$)$

phenotypic characteristics are determined by interactions among several genes.

E$)$

phenotypic characteristics are always controlled by genes on a single chromosome.