Question
Which of the following statements are correct with reference to a transcription unit ? A. A transcription unit in DNA is defined primarily by three regions : promoter, structural gene and terminator. B. The promoter is said to be located towards the 5'-end of the structural gene. C. The promoter is a DNA sequence that provides binding site for RNA polymerase. D. The promoter defines the template and coding strands. E. The terminator is located towards the 3'-end of the coding strand and it defines the end of the process of transcription. Choose the correct answer from the options given below :
Step-by-step solution
Statement A is correct as a transcription unit in DNA is primarily defined by three regions: a promoter, a structural gene, and a terminator. Statement B is correct because the promoter is located towards the 5'-end (upstream) of the structural gene, with reference to the polarity of the coding strand. Statement C is correct as the promoter is a specific DNA sequence that provides a binding site for RNA polymerase to initiate transcription. Statement D is correct because the presence and position of the promoter in a transcription unit define which strand acts as the template and which as the coding strand. Statement E is correct as the terminator is located towards the 3'-end (downstream) of the coding strand and marks the end of the transcription process. Since all statements A, B, C, D, and E are correct, the correct option includes all of them. Answer: A, B, C, D and E