Which one of the following accurately describes the lac operon?
a. rna polymerase is prevented from transcribing the lac genes when lactose is present.
b. rna polymerase transcribes the lac genes when lactose isn't present.
c. the repressor protein binds to the operator when lactose is present.
d. the repressor is freed from the operator when lactose is present.

What are chlorofluorocarbons made of

Acar company is testing seatbelts using crash test dummies. the company finds that when cars come to a sudden stop, the crash test dummies' bodies continue to move forward. the seat belt keeps the crash test dummies from hitting the back of the seat in front of them. why do the crash test dummies' bodies continue to move forward even though the car stopped? a. the friction opposing their bodies' movement keeps them in motion. b. the inertia of their bodies keeps them in motion. c. the forward acceleration of the car keeps them in motion. d. the gravity pulling on the car keeps them in motion.

Anton created a chart listing different types of materials. which best complete the chart?