Final answer:
The claim about the lac operon's operator locations is false; one is upstream, while the remaining two are within structural genes. This contributes to the inducible nature of the operon, which is regulated by lactose and glucose levels.
Step-by-step explanation:
The statement that two of the three lac operon operators are upstream of the transcriptional start site is false. In the lac operon, one operator is upstream of the promoter site (the O1 site), and the other two operator sites, O2 and O3, are located within the structural genes themselves.
O2 is within the lac z gene, and O3 is within the lac I gene. These operator regions are involved in regulating the transcription of the lac operon in response to the presence of lactose and absence of glucose, making the lac operon an inducible operon.