The phenotype of a cell carrying one mutant and one wild type operator site is that LacZ and LacY are produced even in the absence of the inducer IPTG; because the damaged operator site, does not permit binding of the repressor to inhibit transcription of the structural genes.
O fenotipo dunha célula que leve un mutante e un sitio operador de tipo salvaxe é que se producen LacZ e LacY mesmo en ausencia do indutor IPTG; porque o sitio operador danado non permite a unión do represor para inhibir a transcrición dos xenes estruturais.