Final answer:
A loss-of-function mutation in the lacI gene can have the same effect as a mutation in the Operator. When the lacI gene is mutated, it results in the lac repressor protein being non-functional, similar to a mutation in the operator sequence. This allows RNA polymerase to transcribe the structural genes of the lac operon, leading to the expression of proteins involved in lactose metabolism.
Step-by-step explanation:
A loss-of-function mutation in the lacI gene can have the same effect as a mutation in the Operator. The lac operon is a genetic regulatory system found in bacteria, specifically E. coli, which controls the expression of genes involved in lactose metabolism. The lacI gene encodes for the lac repressor protein, which binds to the operator sequence and prevents RNA polymerase from transcribing the structural genes. When there is a loss-of-function mutation in the lacI gene, it means that the lac repressor protein is not produced or non-functional, similar to a mutation in the operator sequence. This results in the inability of the lac repressor to bind to the operator, allowing RNA polymerase to transcribe the structural genes and leading to the expression of proteins involved in lactose metabolism.