What modification is typically part of post-transcription processing?

During post-transcription processing of eukaryotic RNA, the addition of a 5' cap and a poly-A tail is a crucial modification that occurs to the RNA transcript. The 5' cap is a modified guanine nucleotide that is added to the beginning of the mRNA molecule. This cap protects the RNA from degradation, aids in the export of the mRNA from the nucleus, and is necessary for the initiation of translation, helping ribosomes recognize and bind to the mRNA.

Additionally, the poly-A tail, consisting of a string of adenosine monophosphate (AMP) residues, is attached to the 3' end of the RNA molecule. This modification further protects the mRNA from enzymatic degradation in the cytoplasm and also enhances the efficiency of translation. Together, these modifications ensure the stability and functionality of the mRNA before it is translated into protein.

Other processes, such as RNA splicing, involve the removal of introns (non-coding regions) while exons (coding regions) are retained and connected together, but they do not involve the addition of the cap or tail. Therefore, the option regarding the addition of a 5' cap and a poly-A tail captures essential aspects of mRNA maturation