The expression of lac operon in an E. coli cell missing the gene that encodes for the lac repressor will:
A. increase when lactose is present.
B. decrease when lactose is present.
C. decrease when glucose is present.
D. increase when glucose is present.
The lac operon is a group of genes that encode for the enzymes needed in processing lactose as an alternative fuel source. This inducible operon is systematically used to conserve resources and at the same time, so that all necessary enzymes for this particular function are expressed at the same time. This particular operon has two points of control: the negative and positive gene regulation.