In this activity you will use the provided template to have students make a paper model of the lac operon. Students will manipulate the pieces to simulate how the repressor prevents RNA Polymerase from transcribing the genes. They will also be able to see that when lactose is introduced into the system, the repressor is inactivated and transcription can occur. It is used in tandem with a fully animated Powerpoint so you can explain what is happening as they are manipulating the pieces. Teacher instructions are included.