Which best describes the order of actions by rna polymerase?
Answer Choice “A.” is the most sequentially correct answer choice from my understanding. Binding must occur before the making of mRNA, so Answer Choices C and D can be eliminated immediately. If the RNA Polymerase would detach from the DNA before, then how would it make mRNA? That’s when we are left with Answer Choice A, which seems like the best Answer Choice.
D. Binds to DNA, makes mRNA from DNA, detaches.
RNA polymerase is an enzyme involved in transcription, a process of copying DNA into messenger RNA (mRNA). In the transcription, RNA polymerase first binds to DNA separating its two strands. Then, it adds ribonucleotides to the complementary nucleotides on DNA strand and, thus, it makes mRNA from DNA. After mRNA is synthesized, RNA polymerase detaches from DNA, freeing the new mRNA.