The oropharynx is the part of the throat just behind the mouth. It begins where the oral cavity stops. It includes the base of the tongue (the back third of the tongue), the soft palate (the back part of the roof of the mouth), the tonsils, and the side and back wall of the throat.ral cavity cancer, or just oral cancer, is cancer that starts in the mouth (also called the oral cavity). Oropharyngeal cancer starts in the oropharynx, which is the part of the throat just behind the mouth.
polymorphism - (biology) the existence of two or more forms of individuals within the same animal species (independent of sex differences) biological science, biology - the science that studies living organisms
An example of a botanical genetic polymorphism is heterostyly, in which flowers occur in different forms with different arrangements of the pistils and the stamens. The system is called heteromorphic self-incompatibility, and the general 'strategy' of stamens separated from pistils is known as herkogamy. Genetic polymorphism is the simultaneous occurrence in the same locality of two or more discontinuous forms in such proportions that the rarest of them cannot be maintained just by recurrent mutation or immigration, originally defined by Ford (1940).