Which process describes the modification of pre-mRNA into mature mRNA?

The modification of pre-mRNA into mature mRNA is accomplished through splicing. After transcription, the primary RNA transcript (pre-mRNA) undergoes several processing steps to become mature mRNA. This includes the removal of non-coding regions called introns, which are interspersed among the coding sequences known as exons. During splicing, the introns are excised, and the exons are joined together to form a continuous coding sequence that can be translated into a protein.

Additionally, other modifications occur alongside splicing, such as the addition of a 5' cap and a poly-A tail at the 3' end of the mRNA, which are important for mRNA stability, export from the nucleus, and translation efficiency. Therefore, splicing is a critical step in transforming the initially synthesized pre-mRNA into a form that can be effectively translated into proteins.