noncoding DNA

In genetics, non-coding DNA describes DNA which does not contain instructions for making proteins (or other cell products such as noncoding RNAs). In eukaryotes, a large percentage of many organisms' total genome sizes is comprised of noncoding DNA (a puzzle known as the "C-value enigma"). Some noncoding DNA is involved in regulating the activity of coding regions. However, much of this DNA has no known function and is sometimes referred to as "junk DNA".
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