Final answer:
Eukaryotic transcriptional termination involves specific signals recognized by termination proteins for RNA polymerase I or hairpin structures for RNA polymerase III. In eukaryotes, transcription and translation are separated by the nuclear membrane, leading to post-transcriptional mRNA processing. Bacterial cells likely won't transcribe a gene with a eukaryotic promoter due to incompatibility.
Step-by-step explanation:
In eukaryotic transcriptional termination, a variety of signals and processes bring about the completion of mRNA synthesis. For genes transcribed by RNA polymerase I, the termination involves a specific 18-nucleotide sequence that is recognized by a termination protein. On the other hand, genes transcribed by RNA polymerase III terminate in a manner similar to rho-independent termination in prokaryotes, involving the formation of an mRNA hairpin structure.
Unlike prokaryotes where transcription and translation are coupled, eukaryotic cells have a nucleus that separates these processes. Consequently, eukaryotic mRNA undergoes several processing steps post-transcription before being used in translation. The presence of the nuclear membrane ensures that transcription must be completely finished and the mRNA fully processed and exported to the cytoplasm before translation begins.
If a scientist inserts a eukaryotic promoter in front of a bacterial gene within a bacterial chromosome, one would not expect the bacterium to transcribe the gene effectively. This is because bacterial RNA polymerase does not recognize eukaryotic promoters, which are substantially different from bacterial promoters.