What is RNA splicing?

• A. The degradation of RNA
• B. The replication of RNA
• C. The translation of RNA
• D. The removal of introns and joining of exons

Answer: (D)

RNA splicing is the removal of introns and joining of exons in the initial RNA transcript to produce mature messenger RNA. In eukaryotic cells, the first RNA made from a gene (pre-mRNA) contains both coding regions (exons) and noncoding regions (introns). The spliceosome recognizes splice sites, removes introns, and wires the exons together so the mRNA has a continuous coding sequence that can be read by ribosomes during translation. This step is essential for proper gene expression and can even generate different protein variants through alternative splicing.

Other processes listed don’t fit: degrading RNA is RNA turnover, not editing the transcript; replication of RNA is making a copy of RNA itself; translation is the process of converting mRNA into a polypeptide.