You Have Set Up a Cell-Free Transcription System in a Test

Essay

You have set up a cell-free transcription system in a test tube.By mixing DNA,RNA polymerase,sigma factors,ribonucleotides and other essential substances,you are able to make mRNAs identical to those made under a variety of conditions in the cells from which these components were isolated.What would happen if you were able to remove the sigma factor first added to the tube and replace it with another sigma factor?