Assume that you have discovered a new strain of E. coli that has a mutation in the lac operator region that causes the wild-type repressor protein to bind irreversibly to the operator. You have named this operator mutant Osb for “superbinding” operator. 

(a) What phenotype would a partial diploid of genotype I⁺O^sbZ^-Y⁺/I⁺O⁺Z⁺Y^- have with respect to the synthesis of the enzymes β-galactosidase and β-galactoside permease? 

(b) Does your new O^sb mutation exhibit cis or trans dominance in its effects on the regulation of the lac operon?