Looks as if the plate faults, with them rubbing against each other and always moving, mountains are created by plates joining together and going upward for them no where to go.
Like the lac operon, the trp operon is a negative control mechanism. The lac operon responds to an inducer that causes the repressor to dissociate from the operator, derepressing the operon. The trp operon responds to a repressor protein that binds to two molecules of tryptophan.
