Mendelian inheritance in fowls, as a result of parental genes. P = parents, F & F2 = 1st and 2nd generation, D = dominant, R = recessive. Most inherited characteristics or traits are determined by multiple genes (sections of DNA), but some, such as colour in Analusian fowls, are governed by a single gene. These are known as Mendelian, named after Gregor Mendel the founder of genetics. The offspring of most plants and animals contain a mixture of genes from their parents. Certain genes are dominant over others, but if incomplete dominance (or blending) occurs then a new trait will result, in this case a grey colour. Mendelian traits occur in strict mathematical ratios.