9.2 Transcription 入A is catalyzed by RNA polymerase Figure 9.3 Transcription takes place in a bubble, in which RNa is synthesized 入OO by base pairing with one strand ofdna in the transiently unwound region As the bubble progresses NA the dna duplex reforms behind it. displacing the RNA in the form of a single polynucleotide chain 八AO 消当Figure 9.3 Transcription takes place in a bubble, in which RNA is synthesized by base pairing with one strand of DNA in the transiently unwound region. As the bubble progresses, the DNA duplex reforms behind it, displacing the RNA in the form of a single polynucleotide chain. 9.2 Transcription is catalyzed by RNA polymerase