Final answer:
The statement is false, as human cell transcriptional termination is not solely dependent on a stem-loop structure in DNA. In eukaryotes, termination involves a complex set of proteins and processes beyond the formation of a stem-loop structure in the transcribed RNA. The process in eukaryotes typically also includes RNA cleavage and polyadenylation.
Step-by-step explanation:
The statement that transcriptional termination in human cells occurs when a stem-loop structure forms on DNA and creates a physical barrier is false. In human cells, transcriptional termination involves a complex set of proteins and is not simply caused by the formation of a stem-loop structure on DNA. While it is true that in prokaryotes, such as bacteria, transcription can be terminated by the formation of a stem-loop structure that leads to the dissociation of RNA polymerase, in eukaryotic cells like humans, the process is more complex and involves additional factors. Specifically, in Rho-independent termination, the RNA polymerase transcribes a region rich in C-G nucleotides leading to the formation of a RNA hairpin followed by a sequence of weakly bonded A-T (or in RNA, A-U) nucleotides. The formation of this hairpin and the weakly bonded region causes the destabilization necessary for the dissociation of the RNA polymerase and the release of the newly formed mRNA transcript. However, in eukaryotes, such as human cells, the termination process also involves cleavage of RNA and polyadenylation of the transcript, among other factors.