PTC(phenylthiocarbamide) has the unusual property that it either tastes very bitter or is virtually tasteless, depending on the genetic makeup of the taster. The ability to taste PTC is often treated as a dominant genetic trait, although inheritance and expression of this trait are somewhat more complex.

To some people, small amounts of the compounds phenylthiocarbamide (PTC) taste very bitter; other people do not taste these compounds. The myth is that there are only two kinds of people, tasters and non-tasters, and that the trait is controlled by a single gene, with the allele for tasting dominant over the allele for non-tasting.

∴ ability to taste PTC in some individuals is a character that is heritable