In eukaryotes, what processing does mRNA undergo before translation?

In eukaryotes, what processing does mRNA undergo before translation?

• A. Introns are removed; exons are spliced together and mRNA exits the nucleus.
• B. Exons are removed; introns are spliced together and mRNA exits the nucleus.
• C. The mRNA is translated directly in the nucleus.
• D. Splicing occurs after translation in the cytoplasm.

Answer: (A)

Eukaryotic mRNA is processed in the nucleus by removing introns and joining exons, producing a mature transcript that also receives a 5' cap and a poly-A tail. This mature mRNA then exits the nucleus and is translated in the cytoplasm. Intron removal with exon joining is essential because introns are noncoding sequences that must be removed to create a continuous coding sequence. Translation in the nucleus doesn’t occur, and splicing happens before export and translation, not after.

Eukaryotic mRNA is processed in the nucleus by removing introns and joining exons, producing a mature transcript that also receives a 5' cap and a poly-A tail. This mature mRNA then exits the nucleus and is translated in the cytoplasm. Intron removal with exon joining is essential because introns are noncoding sequences that must be removed to create a continuous coding sequence. Translation in the nucleus doesn’t occur, and splicing happens before export and translation, not after.