Question

For each E coli genotype and condition in the following table, choose which sets of functional proteins will or will not be produced.

All grown in media with no/low glucose.

I^S indicates a super-repressor (it can’t bind to lactose/inducers).

O^C indicates a constitutive operon (no repressor can bind to this region of DNA).

I^- ; Z^- ; Y^-each indicate an allele that does not produce a functional protein.

P^- indicates a mutation in the promoter region such that RNA polymerase does not bind.

Lac Genotype	Inducer absent	Inducer present
I- P+ O+ Z+ Y-/ I+ P+ O+ Z- Y+	Functional B-galactosidase Functional permease Functional B-galactosidase No functional permease No functional B-galactosidase Functional permease No functional B-galactosidase No functional permease	Functional B-galactosidase Functional permease Functional B-galactosidase No functional permease No functional B-galactosidase Functional permease No functional B-galactosidase No functional permease
IS P+ O+ Z+ Y-/ I+ P+ O+ Z- Y+	Functional B-galactosidase Functional permease Functional B-galactosidase No functional permease No functional B-galactosidase Functional permease No functional B-galactosidase No functional permease	Functional B-galactosidase Functional permease Functional B-galactosidase No functional permease No functional B-galactosidase Functional permease No functional B-galactosidase No functional permease
I+ P+ OC Z- Y+/ I+ P+ O+ Z+ Y-	Functional B-galactosidase Functional permease Functional B-galactosidase No functional permease No functional B-galactosidase Functional permease No functional B-galactosidase No functional permease	Functional B-galactosidase Functional permease Functional B-galactosidase No functional permease No functional B-galactosidase Functional permease No functional B-galactosidase No functional permease
I- P+ OC Z+ Y-/ I+ P+ O+ Z- Y+	Functional B-galactosidase Functional permease Functional B-galactosidase No functional permease No functional B-galactosidase Functional permease No functional B-galactosidase No functional permease	Functional B-galactosidase Functional permease Functional B-galactosidase No functional permease No functional B-galactosidase Functional permease No functional B-galactosidase No functional permease
IS P+ O+ Z+ Y+/ I+ P+ OC Z+ Y+	Functional B-galactosidase Functional permease Functional B-galactosidase No functional permease No functional B-galactosidase Functional permease No functional B-galactosidase No functional permease	Functional B-galactosidase Functional permease Functional B-galactosidase No functional permease No functional B-galactosidase Functional permease No functional B-galactosidase No functional permease
I+ P- OC Z+ Y-/ I+ P+ O+ Z- Y+	Functional B-galactosidase Functional permease Functional B-galactosidase No functional permease No functional B-galactosidase Functional permease No functional B-galactosidase No functional permease	Functional B-galactosidase Functional permease Functional B-galactosidase No functional permease No functional B-galactosidase Functional permease No functional B-galactosidase No functional permease
I+ P- O+ Z+ Y-/ I+ P+ OC Z- Y+	Functional B-galactosidase Functional permease Functional B-galactosidase No functional permease No functional B-galactosidase Functional permease No functional B-galactosidase No functional permease	Functional B-galactosidase Functional permease Functional B-galactosidase No functional permease No functional B-galactosidase Functional permease No functional B-galactosidase No functional permease
I- P- O+ Z+ Y+/ I+ P+ O+ Z- Y-	Functional B-galactosidase Functional permease Functional B-galactosidase No functional permease No functional B-galactosidase Functional permease No functional B-galactosidase No functional permease	Functional B-galactosidase Functional permease Functional B-galactosidase No functional permease No functional B-galactosidase Functional permease No functional B-galactosidase No functional permease
I- P+ O+ Z+ Y-/ I+ P- O+ Z- Y+	Functional B-galactosidase Functional permease Functional B-galactosidase No functional permease No functional B-galactosidase Functional permease No functional B-galactosidase No functional permease	Functional B-galactosidase Functional permease Functional B-galactosidase No functional permease No functional B-galactosidase Functional permease No functional B-galactosidase No functional permease

Answer 1

Repressor protein can act as both cis and trans mode, superrepressor can binds to operatior even in the presence of inducer, if the operator is constitutive in mode even super repressor can’t bind, the promoter is cis element so, On the basis of these points, the answers are

Lac Genotype	Inducer absent	Inducer present
I- P+ O+ Z+ Y-/ I+ P+ O+ Z- Y+	No functional B-galactosidase No functional permease	Functional B-galactosidase Functional permease
IS P+ O+ Z+ Y-/ I+ P+ O+ Z- Y+	No functional B-galactosidase No functional permease	No functional B-galactosidase No functional permease
I+ P+ OC Z- Y+/ I+ P+ O+ Z+ Y-	No functional B-galactosidase Functional permease	Functional B-galactosidase Functional permease
I- P+ OC Z+ Y-/ I+ P+ O+ Z- Y+	Functional B-galactosidase No functional permease	Functional B-galactosidase Functional permease
IS P+ O+ Z+ Y+/ I+ P+ OC Z+ Y+	Functional B-galactosidase Functional permease	Functional B-galactosidase Functional permease
I+ P- OC Z+ Y-/ I+ P+ O+ Z- Y+	No functional B-galactosidase No functional permease	No functional B-galactosidase Functional permease
I+ P- O+ Z+ Y-/ I+ P+ OC Z- Y+	No functional B-galactosidase Functional permease	No functional B-galactosidase Functional permease
I- P- O+ Z+ Y+/ I+ P+ O+ Z- Y-	No functional B-galactosidase No functional permease	No functional B-galactosidase No functional permease
I- P+ O+ Z+ Y-/ I+ P- O+ Z- Y+	No functional B-galactosidase No functional permease	Functional B-galactosidase No functional permease