What occurs during transcription elongation?

During transcription elongation, RNA polymerase is actively synthesizing the RNA strand by adding nucleotides to the growing chain. This process occurs after the initiation phase, where RNA polymerase assembles at the promoter region and unwinds the DNA strands. As it progresses along the DNA template strand, RNA polymerase incorporates ribonucleotides that are complementary to the DNA template, extending the RNA transcript in the 5' to 3' direction.

This addition of nucleotides is a crucial aspect of gene expression, as it allows for the formation of a complete RNA molecule that ultimately may be translated into a protein or functional RNA, depending on the gene being expressed. The elongation phase continues until RNA polymerase encounters a termination signal, leading to the end of transcription.

In contrast, the other options relate to different aspects of transcription or its regulation. Termination happens after elongation, while the reformation of the DNA double helix is not a highlight of elongation itself; instead, it occurs naturally as RNA polymerase moves along the DNA and the region behind it closes up. Positive regulatory factors may influence the initiation of transcription but are not specifically released during the elongation phase.