Molecular Biology of the Gene 7th Edition by Richard Losick, James Watson, Michael Levine, Tamara Baker, Alexander Gann

Exercise 8

Given the following mutants and conditions, predict the expression of the of the lacZ gene (no expression, basal level of expression, or activated level of expression).
A. A mutant of E. coli that has a mutation in the operator of the lac operon that prevents the repressor from binding
a. In the presence of glucose, absence of lactose
b. In the presence of glucose, presence of lactose
c. In the absence of glucose, absence of lactose
d. In the absence of glucose, presence of lactose
B. A mutant of E. coli that has a mutation in the promoter of the lac operon (for the lacZ , lacY , and lacA genes) that prevents RNA polymerase from binding
a. In the presence of glucose, absence of lactose
b. In the presence of glucose, presence of lactose
c. In the absence of glucose, absence of lactose
d. In the absence of glucose, presence of lactose