Question: Mutations may have an effect on the expression of an operon such as the lac operon. Would the fol…

Mutations may have an effect on the expression of an operon such
as the lac operon. Would the following mutations have a cis- or
trans-effect on the expression of the structural genes in the
operon?

a) A mutation in the operator site that prevents the lac
repressor from binding to it

b) A mutation in the lacI gene that prevents the lac repressor
from binding to DNA

c) A mutation in lac promoter that prevents RNA polymerase from
binding to it