Question

The lac operon genes are transcribed together in what order?

a) lacZ, lacY, lacA
b) lacY, lacZ, lacA
c) lacA, lacZ, lacY
d) lacA, lacY, lacZ

Answer 1

The lac operon genes are transcribed together in the order of lacZ, lacY, lacA, which is represented by option a). These genes allow E. coli to utilize lactose by encoding enzymes for its metabolism.

Step-by-step explanation:

The lac operon genes are transcribed together in the order lacZ, lacY, lacA. The lacZ gene encodes ß-galactosidase, which breaks lactose into galactose and glucose. The lacY gene encodes lactose permease, which facilitates the entry of lactose into the cells. Finally, the lacA gene encodes a transacetylase, whose function in lactose metabolism is less understood. These genes are expressed in the presence of lactose, which acts as an inducer to lift repression, allowing transcription to proceed.

The correct order for the transcription of the lac operon genes is: a) lacZ, lacY, lacA.