An example of prokaryotic gene expression is the lac operon. When a person is , they do not produce the enzyme . Lactase aids in the digestion of lactose, the sugar found in . If a person is lactose intolerant and eats dairy, lactose travels farther down the digestive tract into the large intestine, where the genes in the bacteria, , are turned on. Since the person can’t digest the lactose, E. coli wants to use it as an energy source. The activated genes in E. coli will create the / needed to digest the lactose. In E. coli, when lactose is present, lactose acts as an inducer and binds to the protein, keeping it from attaching to the . When the repressor is blocked from attaching, will attach and the gene by matching up . When lactose is NOT present, the protein binds to the and transcription is blocked. This is an example of gene expression (production of proteins) being controlled at .
Question 1 options:
Please fill in the blanks using the following words:

lactase
repressor
transcribe
dairy products
E. coli
RNA polymerase
operator
transcription
repressor
operator
lactose intolerant
proteins
enzymes
bases