9.1 Introduction Figure 9.2 A transcription unit 20-10+1+10+20+30+40 is a sequence of DNA transcribed into a single RNa Startpoint starting at the Promoter proximal distal Terminator promoter and ending at the terminator Upstream Downstream 消当Figure 9.2 A transcription unit is a sequence of DNA transcribed into a single RNA, starting at the promoter and ending at the terminator. 9.1 Introduction