What is the primary difference between RNA editing and alternative splicing?

What is the primary difference between RNA editing and alternative splicing?

• A. RNA editing chemically alters nucleotides after transcription; alternative splicing changes which exons are included in the final mRNA.
• B. RNA editing occurs during DNA replication; alternative splicing changes intron removal.
• C. RNA editing only occurs in prokaryotes; alternative splicing only in eukaryotes.
• D. RNA editing is the same as alternative splicing.

Answer: (A)

RNA editing and alternative splicing are both post-transcriptional RNA processes, but they affect RNA in different ways. RNA editing chemically changes specific nucleotides within an RNA molecule after it has been transcribed, such as converting one base to another, which can alter codons and regulatory sites without changing the actual order of exons. Alternative splicing, on the other hand, changes which exons are included in the mature mRNA, by removing introns and joining different exons, so the nucleotide sequence of the included exons stays the same but the exon composition varies. So the main distinction is that editing modifies bases, while splicing rearranges which exons are present in the final transcript. The other statements don’t fit because editing is not tied to DNA replication and does not involve removing exons, splicing is not about editing nucleotide identities, and the two processes are distinct, not the same.

RNA editing and alternative splicing are both post-transcriptional RNA processes, but they affect RNA in different ways. RNA editing chemically changes specific nucleotides within an RNA molecule after it has been transcribed, such as converting one base to another, which can alter codons and regulatory sites without changing the actual order of exons. Alternative splicing, on the other hand, changes which exons are included in the mature mRNA, by removing introns and joining different exons, so the nucleotide sequence of the included exons stays the same but the exon composition varies. So the main distinction is that editing modifies bases, while splicing rearranges which exons are present in the final transcript. The other statements don’t fit because editing is not tied to DNA replication and does not involve removing exons, splicing is not about editing nucleotide identities, and the two processes are distinct, not the same.