The Promotion of the Lac Operon in Bacteria is ________________________

Question

The promotion of the lac operon in bacteria is ________________________.  
A) activated by a repressor protein
B) dependent on lactose concentration
C) dependent on glucose concentration
D) regulated by RNA polymerase
E) regulated by mRNA

Accepted Answer

The lac operon in bacteria is promoted by the presence of lactose, as it acts as an inducer that binds to a regulatory protein, known as the lac repressor, causing it to release its hold on the promoter region. This allows RNA polymerase to transcribe the genes of the lac operon, including the genes that code for enzymes involved in lactose metabolism. Glucose concentration is also an important factor in regulating the lac operon, as it acts as a catabolite repressor, meaning it prevents the transcription of the lac operon genes in the presence of glucose, even if lactose is also present. However, this does not directly promote the lac operon. RNA polymerase and mRNA are also involved in the process of gene expression, but they are not directly responsible for promoting the lac operon.