Polymorphism

Polymorphism or dimorphism may refer to:

Biology

 * Polymorphism (biology), including:
 * having multiple phenotypes within a population; the switch that determines which phenotype an individual displays can be genetic or environmental
 * includes Sexual dimorphism, differences in the physiology of a species based only on sex
 * having multiple alleles of a gene within a population, usually expressing different phenotypes
 * Lipid polymorphism, the property of amphiphiles that gives rise to various aggregations of lipids
 * Nuclear dimorphism, when a cell's nuclear apparatus is composed of two structurally and functionally differentiated types of nuclei
 * Frond dimorphism, differing forms of fern fronds between the sterile and fertile fronds

Computing

 * Polymorphism (computer science), allowing program code to work with various types
 * Polymorphism in object-oriented programming, the ability of an interface to be realized in multiple ways
 * Dialog polymorphism, changing the form of a computer dialog every time it is presented to a user, in order to prevent habituation
 * Polymorphic code, self-modifying program code designed to defeat anti-virus programs or to defeat reverse engineers

Chemistry

 * Polymorphism (materials science), the ability of a solid material to exist in more than one form or crystal structure

Medicine

 * A type of QRS complex seen on an electrocardiogram

Psychology

 * Polymorphous perversity, a concept in psychoanalytic theory