| segments of DNA that have no apparent genetic function. |
| junk DNA n. DNA that does not code for proteins or their regulation but constitutes approximately 95 percent of the human genome. It is postulated to be involved in the evolution of new genes and possibly in gene repair. |
junk DNA  (jŭngk) Pronunciation Key
DNA that serves no known biological purpose, such as coding for proteins or their regulation. Junk DNA makes up the vast majority of the DNA in the cells of most plants and animals, composing, for example, about 95 percent of the human genome. |