In prokaryotes and eukaryotes, how does termination differ?

• A. Prokaryotes use a DNA terminator sequence; Eukaryotes use a polyadenylation signal AAUAA and cleavage
• B. Prokaryotes use a polyadenylation signal; Eukaryotes use a Rho-dependent termination
• C. Both rely on the same terminator mechanism
• D. Termination is not needed in transcription

Answer: (A)

The main idea is that transcription termination in bacteria is driven by signals encoded in the DNA that cause the RNA polymerase to stop, either through intrinsic terminators or via the Rho factor. In contrast, termination for eukaryotic RNA polymerase II transcripts is tied to RNA processing: the pre-mRNA is cleaved at a polyadenylation site marked by the AAUAAA signal, and a poly(A) tail is added, with this processing helping to end transcription. So describing prokaryotes as using a DNA terminator sequence and eukaryotes as using a polyadenylation signal with cleavage captures the essential differences. The other options mix up which system uses which mechanism or wrongly claim termination isn’t needed.