<P> In genomics and related disciplines, noncoding DNA sequences are components of an organism's DNA that do not encode protein sequences . Some noncoding DNA is transcribed into functional non-coding RNA molecules (e.g. transfer RNA, ribosomal RNA, and regulatory RNAs). Other functions of noncoding DNA include the transcriptional and translational regulation of protein - coding sequences, scaffold attachment regions, origins of DNA replication, centromeres and telomeres . </P> <P> The amount of noncoding DNA varies greatly among species . Often, only a small percentage of the genome is responsible for coding proteins, but a rising percentage is being shown to have regulatory functions . When there is much non-coding DNA, a large proportion appears to have no biological function, as predicted in the 1960s . Since that time, this non-functional portion has controversially been called "junk DNA". </P>

What are three end products encoded by dna that are not proteins