How does mRNA processing differ between prokaryotes and eukaryotes?

How does mRNA processing differ between prokaryotes and eukaryotes?

• A. Eukaryotes add 5' caps and 3' poly-A tails and undergo splicing; prokaryotes transcribe and translate simultaneously and generally do not process introns.
• B. Prokaryotes add 5' caps and 3' poly-A tails; Eukaryotes transcribe and translate simultaneously.
• C. Both prokaryotes and eukaryotes process introns identically.
• D. Eukaryotes do not process mRNA; prokaryotes do.

Answer: (A)

Eukaryotic mRNA must be matured after transcription to become ready for translation, while prokaryotic mRNA is usually ready to be translated almost immediately and often doesn’t require processing. In eukaryotes, the RNA transcript is made in the nucleus and undergoes several modifications: a 5' cap is added, a 3' poly-A tail is added, and introns are removed by splicing. These steps protect the message, aid export from the nucleus, and help the ribosome recognize the start of translation. In contrast, prokaryotes lack a separate nucleus, so transcription and translation can occur at the same time, and most prokaryotic genes have few or no introns, meaning splicing is generally unnecessary. This combination explains why the statement that eukaryotes add 5' caps and 3' poly-A tails and undergo splicing, while prokaryotes transcribe and translate simultaneously and generally do not process introns, is correct. The other descriptions misstate where processing occurs or what kinds of processing happen.

Eukaryotic mRNA must be matured after transcription to become ready for translation, while prokaryotic mRNA is usually ready to be translated almost immediately and often doesn’t require processing. In eukaryotes, the RNA transcript is made in the nucleus and undergoes several modifications: a 5' cap is added, a 3' poly-A tail is added, and introns are removed by splicing. These steps protect the message, aid export from the nucleus, and help the ribosome recognize the start of translation. In contrast, prokaryotes lack a separate nucleus, so transcription and translation can occur at the same time, and most prokaryotic genes have few or no introns, meaning splicing is generally unnecessary. This combination explains why the statement that eukaryotes add 5' caps and 3' poly-A tails and undergo splicing, while prokaryotes transcribe and translate simultaneously and generally do not process introns, is correct. The other descriptions misstate where processing occurs or what kinds of processing happen.