Question

Mutations may have an effect on the expression of the lac operon, the ara operon, and the trp 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 lad gene that prevents the lac repressor from binding to DNA C. A mutation in the araC gene that prevents two AraC proteins from binding to each other and forming a loop D. A mutation in trpL that prevents attenuation