You decide to focus first on Mutation 1 and Mutation 2. The F' plasmid appears to "rescue" mutant strain 1 by restoring wild-type inducible expression. The F' plasmid does not change the phenotype of mutant strain 2; there is still no expression of the lac operon. There are three possible mutations that could lead to lack of expression: a super-repressor (Is), a promoter mutation (P-) or a mutation in the lacZ gene (Z- ). To determine the effect of introducing a wild-type F' plasmid into a bacterial cell with each of these mutations, you draw out the three possible scenarios. Three possible partial diploids: (1) F' lac+/P- (2) F' lac+/Z- (3)F' lac+/I^S