Which stage is characterized by RNA polymerase binding to the promoter?

The stage characterized by RNA polymerase binding to the promoter is known as initiation. During this phase of transcription, RNA polymerase attaches to the promoter region of a gene, which is a specific DNA sequence that marks the beginning of the gene. This binding is crucial because it allows the enzyme to unwind the DNA strands and start synthesizing RNA.

The initiation phase is the first step in the process of transcription, which ultimately leads to the production of RNA from a DNA template. It is during this stage that various transcription factors may also be involved, assisting in the recruitment of RNA polymerase to the promoter and ensuring that transcription begins at the correct location.

In contrast, elongation is the stage where RNA polymerase moves along the DNA, adding RNA nucleotides to the growing RNA strand. Termination marks the end of the transcription process when RNA polymerase stops synthesizing RNA, and splicing refers to the modification of the newly synthesized RNA transcript by removing introns and joining exons together. Therefore, initiation is specifically defined by the binding of RNA polymerase to the promoter, making it the defining characteristic of this crucial phase in gene expression.