New protein-coding genes sometimes originate when exons from different ancestral genes are combined through recombination events, producing a novel domain architecture within a single polypeptide. This mechanism of generating new genes is called:

Correct option is A

Correct Answer:  (a)
Explanation: Exon shuffling refers to the evolutionary process by which exons from different genes are recombined to form new genes with novel domain combinations. Because exons often encode functional protein domains, their recombination can generate proteins with new functions. This process commonly occurs via recombination events or transposon-mediated rearrangements during evolution. Hence, exon shuffling best explains the origin of such novel protein-coding genes.
Information Booster
· Exons frequently correspond to discrete functional or structural protein domains.
· Exon shuffling accelerates protein evolution by creating new domain architectures.
· Introns facilitate exon shuffling by serving as recombination-friendly regions.
· Many multidomain proteins in eukaryotes evolved through exon shuffling.
· This mechanism contributes to functional innovation without disrupting existing genes.
Additional Knowledge
Alternative splicing generates multiple isoforms from a single gene but does not create new genes combining exons from different ancestral loci. Retroposition produces gene copies lacking introns and regulatory sequences rather than novel exon combinations. Transposon insertion mainly alters gene regulation or disrupts genes, rather than assembling new coding architectures. Therefore, exon shuffling is the specific mechanism that explains the described origin of new protein-coding genes.