Which step(s) are required to produce a mature FL-SMN transcript?Addition of multiple adenine nucleotides to the 3′ end of SMN1 pre-mRNARemoval of the 7-methylguanosine cap from mature mRNADNA polymerase binding to the SMN1 geneA.I onlyB.I and III onlyC.II and III onlyD.I, II, and III

The steps required to produce a mature FL-SMN transcript include:

1. DNA polymerase binding to the SMN1 gene: This is the first step in the process of transcription where the enzyme DNA polymerase binds to the specific gene that needs to be transcribed.

2. Addition of multiple adenine nucleotides to the 3′ end of SMN1 pre-mRNA: This process is known as polyadenylation. It is a crucial step in the maturation of pre-mRNA into mRNA. It helps in the stability of the mRNA and also aids in the export of the mRNA from the nucleus to the cytoplasm.

3. Removal of the 7-methylguanosine cap from mature mRNA: This is not a step in the production of a mature FL-SMN transcript. The 7-methylguanosine cap is added to the 5' end of the pre-mRNA during the process of transcription and it remains there in the mature mRNA. It helps in the stability of the mRNA and also aids in the initiation of translation.

So, the correct answer is B. I and III only.