How does transcription termination differ in prokaryotes vs eukaryotes?

How does transcription termination differ in prokaryotes vs eukaryotes?

• A. Prokaryotes use rho-dependent/independent termination; eukaryotes rely on polyadenylation signals and transcription termination processes
• B. Prokaryotes use polyadenylation; eukaryotes use rho termination
• C. Both use the same termination mechanism via hairpin loops
• D. Termination occurs only during translation

Answer: (A)

Transcription termination shows a clear difference because bacteria and eukaryotes handle the end of transcription with different partners and processes. In bacteria, termination can happen through a rho-dependent mechanism, where the Rho helicase binds the RNA and uses energy to chase down RNA polymerase and cause release, or through an intrinsic (rho-independent) route, which relies on a GC-rich region forming a hairpin in the RNA followed by a string of uracils that destabilizes the transcription complex. In eukaryotes, termination is tightly linked to RNA processing: the primary transcript is cleaved and polyadenylated at a polyadenylation signal, and termination of RNA polymerase II transcription is coordinated with this 3' end processing, often via a torpedo-like mechanism. So the best answer captures that prokaryotes use rho-dependent or intrinsic signals, while eukaryotes rely on polyadenylation signals and processing-linked termination. The other statements misstate the roles—prokaryotes don’t terminate via polyadenylation, eukaryotes don’t terminate via rho, and termination isn’t limited to translation.

Transcription termination shows a clear difference because bacteria and eukaryotes handle the end of transcription with different partners and processes. In bacteria, termination can happen through a rho-dependent mechanism, where the Rho helicase binds the RNA and uses energy to chase down RNA polymerase and cause release, or through an intrinsic (rho-independent) route, which relies on a GC-rich region forming a hairpin in the RNA followed by a string of uracils that destabilizes the transcription complex. In eukaryotes, termination is tightly linked to RNA processing: the primary transcript is cleaved and polyadenylated at a polyadenylation signal, and termination of RNA polymerase II transcription is coordinated with this 3' end processing, often via a torpedo-like mechanism. So the best answer captures that prokaryotes use rho-dependent or intrinsic signals, while eukaryotes rely on polyadenylation signals and processing-linked termination. The other statements misstate the roles—prokaryotes don’t terminate via polyadenylation, eukaryotes don’t terminate via rho, and termination isn’t limited to translation.