Answer: (D) They are performed with linked genes but not with unlinked genes; The complementation test is also called as cis-trans test. It is used to determine whether two mutations associated with a specific phenotype represent two different forms of the same gene (alleles) (AB/ab) or are variations of two different genes (Ab/aB). The complementation will not occur if the mutations are in the same gene It is relevant for recessive traits (traits normally not present in the phenotype due to masking by a dominant allele). Solution Answer: (D) They are performed with linked genes but not with unlinked genes; The complementation test is also called as cis-trans test. It is used to determine whether two mutations associated with a specific phenotype represent two different forms of the same gene (alleles) (AB/ab) or are variations of two different genes (Ab/aB). The complementation will not occur if the mutations are in the same gene It is relevant for recessive traits (traits normally not present in the phenotype due to masking by a dominant allele)..