Which of the following statements describes the function of the sigma factor in prokaryotic transcription? - it catalyzes the removal of the introns to produce mature mrna to terminate transcription. - it causes the rna polymerase to detach from the mrna to terminate transcription. - it catalyzes the synthesis of mrna in a 5' to 3' direction to implement transcription elongation. - it attaches the amino acid to its cognate trna to initiate translation. - it facilitates the binding of rna polymerase to the promoter to initiate transcription.