Question

A low level of expression of the lac operon occurs at all times. Can you explain the logic behind this phenomenon?

Answer 1

In the complete absence of expression of the lac operon, permease will not be synthesised, which is essential for the transport of lactose from the medium into the cells. And if lactose cannot be transported into the cell, then it cannot act as an inducer; hence, it cannot relieve the lac operon from its repressed state.