Question

A) Given the following genotypes of E. coli strains, predict whether the lacZ gene will be inducibly expressed, constitutively expressed, or permanently repressed in the presence of lactose as the only sugar.

Genotype                   

I+O+Z+  will have the lacZ gene __________ ,  because  __________

I-O+Z+   will have the lacZ gene  __________ ,  because __________   

I^SO+Z+   will have the lacZ gene __________ ,  because  __________​     

I+O^CZ+   will have the lacZ gene  __________ ,  because __________​             

I^SO^CZ+ will have the lacZ gene  __________ ,  because  __________    

B) The following strains of E. coli carry a plasmid indicated by F' that has a green fluorescent protein (GFP) downstream of the operator O locus. Given these genotypes, predict whether the GFP gene will be inducibly expressed, constitutively expressed, or permanently repressed in the presence of lactose as the only sugar.

Genotype   

I+O+Z+/F'O+GFP   will have the GFP gene  __________

I-O+Z+/F'O+GFP     will have the GFP gene  __________  

I^SO+Z+/F'O+GFP     will have the GFP gene  __________

I^SO+Z+/F'O^CGFP      will have the GFP gene  __________

The above experiments using a plasmid provide evidence that the I locus acts  __________  and that the O locus acts __________.

Answer 1

Answer 2