Phenocopies:
Phenocopies are mimics of some other phenotype induced by environmental influence. It means that individuals with different genotypes may have the same phenotype due to the effect of the environment. It can be induced by temperature shocks, radiation, poison, vitamin deficiencies, and a wide range of chemical agents and drugs. Changes resulting in phenocopies are not induced.
Example: Phenocopies are observed in insects, birds, and mammals. Goldschmidt (1935) induced phenocopies in Drosophila by raising them at a higher room temperature of 35°C.
Conditional Mutants:
Conditional mutations are those gene mutations that produce one phenotype under one set of conditions and another phenotype under changed conditions.
Example: Temperature-sensitive mutants (ts) express their wild-type phenotype at a permissible temperature but exhibit lethal phenotype at a restricted temperature.