junk DNA

1. segments of DNA that have no apparent genetic function.

junk DNA

noun

1. DNA that consists of repeated sequences of nucleotide and has no apparent function

junk DNA

/ jŭngk /

1. 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.

“junk” DNA

1. Segments of DNA along a chromosome that are not genes , do not code for anything that we know of, and whose purpose we do not understand. Approximately ninety-five percent of the human genome falls into this category. The term junk may be misleading, however, as this DNA may have other functions, such as regulating genes during development.

Notes

Some scientists speculate that junk DNA may be archaic material left over from an earlier stage of evolutionary development.

Word History and Origins

Origin of junk DNA¹

1990–95

Example Sentences

Half a century ago, scientists dismissed this noncoding stuff as “junk DNA,” a term now considered “a reflection of our own ignorance,” Leitch said.

From Los Angeles Times

Until recently, it was assumed that these 'fossil viruses' were simply junk DNA, with no important function in the body.

From Science Daily

The researchers studied junk DNA in a genome that has de-evolved.

From Science Daily

Repeats of DNA sequences, often referred to as "junk DNA" or "dark matter," that are found in chromosomes and could contribute to cancer or other diseases have been challenging to identify and characterize.

From Science Daily

About 40% of the human genome is made up of this "selfish" new DNA, though most of the genes are disabled, so-called junk DNA.

From Science Daily