, polygenic inheritance refers to traits that are controlled by three or more genes and are often influenced by the environment. The classic example provided in the text is Human skin colour, which is controlled by at least three genes (A, B, C) with an additive effect .

In contrast:

• Flower colour in Mirabilis jalapa (or Antirrhinum) is an example of incomplete dominance .
• Production of male honey bees occurs via parthenogenesis (haplodiploid sex determination) .
• Pod shape in garden pea is a Mendelian trait controlled by a single gene .