Several examples of antisense RNA regulating translation in bacterial cells have been discovered Molecular geneticists have also used antisense RNA to artificially control transcription in both bacterial and eukaryotic genes. If you wanted to inhibit the transcription of a bacterial gene with antisense RNA, what sequence might the antisense RNA contain?
A. a sequence that is identical to the gene that codes for RNA polymerase
B. a sequence complementary to the structural gene
C. a sequence complementary to the promoter of the operon
D. a sequence complementary to the 3' UTR
E. a sequence complementary to a 5-UTR

MicroRNAs (miRNAs) and small interfering RNAs (siRNAs) are two major classes of small non-coding RNAs (sncRNAs) that function to control gene expression by binding to complementary RNA transcripts. Antisense oligonucleotides exploit this natural ability of the sncRNAs to regulate target gene expression.

An operon is a procaryotic single-strand DNA that contains a group of genes modulated by one single promoter, which are transcribed together to produce a single polycistronic messenger RNA (mRNA). In this example, the antisense complementary oligonucleotide will bind to the mRNA to modulate its transcription and, consequently, also protein synthesis.