Which statement about eukaryotic mRNA processing is true?

Which statement about eukaryotic mRNA processing is true?

• A. mRNA is immediately translated without processing.
• B. Splicing occurs in prokaryotes.
• C. capping occurs in mitochondria.
• D. mRNA in eukaryotes undergoes capping, splicing, and polyadenylation.

Answer: (D)

Eukaryotic mRNA must be processed to become functional. The main maturation steps are adding a 5' cap, removing introns by splicing, and adding a poly(A) tail at the 3' end. The 5' cap protects the transcript from degradation and helps recruit the ribosome for translation. Splicing removes noncoding introns and joins together exons, and it can generate different protein products through alternative splicing. The poly(A) tail increases mRNA stability, aids export from the nucleus, and enhances translation efficiency. These processing events are characteristic of eukaryotic mRNA and occur in the nucleus before the message is exported for translation. The other statements aren’t accurate: splicing isn’t a typical feature of prokaryotes, capping isn’t a mitochondria-specific process for standard nuclear-encoded mRNA, and translation generally cannot occur without these processing steps.

Eukaryotic mRNA must be processed to become functional. The main maturation steps are adding a 5' cap, removing introns by splicing, and adding a poly(A) tail at the 3' end. The 5' cap protects the transcript from degradation and helps recruit the ribosome for translation. Splicing removes noncoding introns and joins together exons, and it can generate different protein products through alternative splicing. The poly(A) tail increases mRNA stability, aids export from the nucleus, and enhances translation efficiency. These processing events are characteristic of eukaryotic mRNA and occur in the nucleus before the message is exported for translation. The other statements aren’t accurate: splicing isn’t a typical feature of prokaryotes, capping isn’t a mitochondria-specific process for standard nuclear-encoded mRNA, and translation generally cannot occur without these processing steps.