The term phenotype represents the observable, outward features of an organism, resulting from both its genetic constitution, or what is coded within its DNA, and the influence of the environment. Genetic variants can be critically important influences on the developmental potential and limitations of an organism, from the embryonic stage to adulthood. Sometimes these genomic influences can, on their own, result in observable characteristics including behavior, morphology, and biochemical and physiological properties. Yet, environment can also influence the development of inherited traits; for example, the availability of adequate nutrition can influence size and growth. This entry further describes the idea of the phenotype and discusses the practice and purpose of phenotyping and dysmorphology, or the study of abnormal form.

The word phenotype originates from the German ...