In biology, a<unk>  is a regulatory region of DNA generally located upstream (towards the 5' region of the anti-sense strand) of a gene that generally <unk>  transcription of the gene.
The<unk>  contains specific DNA sequences, response elements, that are recognized by proteins known as transcription factors. These factors bind to the<unk>  sequences, recruiting RNA polymerase, the enzyme that synthesizes the RNA from the coding region of the gene.
In prokaryotes, the<unk>  is recognized by RNA polymerase and an associated sigma factor, which in turn are brought to the<unk>  DNA by an activator protein binding to its own DNA sequence nearby.
In eukaryotes, the process is more complicated, and at least seven different factors are necessary for the binding of an RNA polymerase II to the<unk> .<unk> s represent critical elements that can work in concert with other regulatory regions (enhancers, silencers, boundary elements/insulators) to direct the level of transcription of a given gene.
It is worth noting that<unk> s are not DNA specific, and can in fact locate upstream towards the 3' end of an RNA genome, e.g. Respiratory Syncytial Virus (RSV).
Promoter
Cytome
Telomere
Centromere
Open reading frame
Locus 
DNA end
Ribozyme