Final answer:
The primary difference between rho-dependent and rho-independent termination in prokaryotes lies in the formation of a terminator hairpin during rho-independent termination, which disrupts the transcription process without the need for the rho protein.
Step-by-step explanation:
The main distinguishing structure between rho-dependent and rho-independent termination in prokaryotes is the terminator hairpin. Rho-dependent termination is controlled by the rho protein, which causes the RNA polymerase to stall at a run of G nucleotides on the DNA template. Conversely, rho-independent termination involves a DNA sequence that causes the formation of an mRNA hairpin loop structure when transcribed. This hairpin is rich in C-G nucleotides and, followed by a region rich in A-T nucleotides, induces instability that separates the mRNA transcript from the DNA template and the RNA polymerase.
The main structure distinguishing Ə-dependent and Ə-independent termination in prokaryotes is the terminator hairpin. In rho-independent termination, as the RNA polymerase nears the end of the gene being transcribed, it encounters a region rich in C-G nucleotides. The mRNA folds back on itself, forming a stable hairpin that causes the polymerase to stall. This hairpin structure then leads to the dissociation of the RNA polymerase from the DNA template and the release of the newly formed mRNA transcript.