Splicing is a process of
**Core Concept**
Splicing is a post-transcriptional modification process that removes non-coding regions, known as introns, from a pre-mRNA molecule and joins the coding regions, or exons, together to form a mature mRNA molecule. This process is crucial for the production of functional proteins from the genetic information encoded in the DNA.
**Why the Correct Answer is Right**
During splicing, the introns are recognized and removed by a complex enzyme called the spliceosome, which is composed of small nuclear ribonucleoproteins (snRNPs). The spliceosome catalyzes the removal of the introns and the ligation of the exons, resulting in the formation of a mature mRNA molecule. This process is essential for the removal of non-coding regions that would otherwise disrupt the translation of the mRNA into a protein.
**Why Each Wrong Option is Incorrect**
**Option A:** Activation of protein refers to the post-translational modification of a protein, which is a different process from splicing.
**Option C:** Synthesis of protein refers to the process of translation, where the ribosomes read the mRNA and assemble amino acids into a polypeptide chain.
**Option D:** Replication of DNA is the process by which a cell makes an exact copy of its DNA during the cell cycle.
**Clinical Pearl / High-Yield Fact**
The process of splicing is critical for the removal of introns, which are non-coding regions that can disrupt the translation of the mRNA into a protein. The spliceosome is a complex enzyme that recognizes and removes introns, and its dysfunction can lead to genetic disorders such as muscular dystrophy.
✓ Correct Answer: B. Removal of introns