Phenocopy

A phenocopy is an individual whose phenotype (generally referring to a single trait), under a particular environmental condition, is identical to the one of another individual whose phenotype is determined by the genotype. In other words the phenocopy environmental condition mimics the phenotype produced by a gene.

An incorrect example of a phenocopy is a person with bleached brunette hair; the bleached hair is intended to mimic genetically determined blonde hair of actual blonde people. The false phenocopy can be easily distinguished by observing the roots of the hair or by shining an ultraviolet light on the bleached brunette hair.

A correct example of a phenocopy is a person whose anti-psychotic medication causes them to manifest the same symptoms as the genetically determined Parkinsons disease.

An example of a phenocopy are the Vanessa genus of butterflies who can change phenotype based on the local temperature. If introduced to Lapland they mimic butterflies localised to this area and if localised to Syria they mimic buterflies of this area. These phenotypes aren't inherited and are solely down to environment.

It is not a type of mutation.