Final answer:
Rho-independent termination in bacterial transcription occurs when the RNA polymerase encounters a region rich in C-G nucleotides near the end of the gene being transcribed, causing the polymerase to stall and the formation of a stable hairpin loop. This loop, along with a weak interaction between the mRNA transcript and the template DNA, leads to the release of the mRNA transcript.
Step-by-step explanation:
Rho-independent termination in bacterial transcription occurs when the RNA polymerase encounters a region rich in C-G nucleotides near the end of the gene being transcribed. At this point, the mRNA folds back on itself, forming a stable hairpin loop with complementary C-G nucleotides binding together. This hairpin loop causes the polymerase to stall, preventing further transcription. A region rich in A-T nucleotides follows the hairpin loop, and the weak interaction between the complementary U-A region of the mRNA transcript and the template DNA, along with the stalled polymerase, induce enough instability for the polymerase to break away and release the newly synthesized mRNA transcript.