Final answer:
In eukaryotes, RNA Polymerase II transcribes beyond the end of the gene, and the tail is removed during mRNA processing. RNA Polymerase I requires a specific sequence recognized by a termination protein, while RNA Polymerase III uses an mRNA hairpin for termination. Prokaryotic cells can simultaneously transcribe and translate due to the absence of a nucleus, while eukaryotic cells cannot.
Step-by-step explanation:
In eukaryotes, termination of transcription is different for the three different RNA polymerases. RNA Polymerase II transcribes 1,000-2,000 extra nucleotides beyond the end of the gene. This tail is subsequently removed during mRNA processing. Genes transcribed by RNA polymerase I contain a specific 18- nucleotide sequence that is recognized by a termination protein. The process of termination in RNA polymerase III involves an mRNA hairpin similar to rho-independent termination of transcription in prokaryotes.
Upon termination, the process of transcription is complete. By the time termination occurs, the prokaryotic transcript would already have been used to begin synthesis of numerous copies of the encoded protein because these processes can occur concurrently. The unification of transcription and translation is possible because there is no nucleus in the prokaryotic cell. In contrast, the presence of a nucleus in eukaryotic cells precludes simultaneous transcription and translation.