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
Genetic polymorphism. Definition. noun. (1) The existence together of many forms of DNA sequences at a locus within the population. (2) A discontinuous genetic variation that results in different forms or types of individuals among the members of a single species.Supplement. Genetic polymorphism promotes diversity within a population.It often persists over many generations because no single form has an overall advantage or disadvantage over the others regarding natural selection. A common example is the different allelic forms that give rise to different blood types in humans.enetic polymorphism promotes diversity within a population. It often persists over many generations because no single form has an overall advantage or disadvantage over the others regarding natural selection.