The product of the lacI gene functions most like a car's ________.
A) parking brake
B) accelerator pedal
C) steering wheel
D) engine
E) gear shift

Question

Quizplus · Accepted Answer

The lacI gene acts as a repressor for the lac operon, preventing the expression of genes involved in lactose metabolism. This repression can be thought of as a "brake" that stops the expression of these genes until lactose is present and needed as an energy source. Just like a parking brake prevents a car from moving until released.

The Product of the LacI Gene Functions Most Like a Car's