Question

Consider two E. coli mutants: Mutant 1 has mutation in LacI, such that the protein can no longer bind DNA. Mutant 2 has a mutation in the operator, such that LacI can no longer bind to it. What will be the phenotype of these mutants? (Assume there is no glucose present

Answer 1

Mutant 1 will not be experimenting beta-galactosidade even if there is no lactose present; The mutant 2 will be experimenting beta-galactosidase in a very large amount whether there is lactose present or not.

Neither mutant will be experimenting beta-galactosidase even if there is not lactose present.