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- DictionaryDNA/ˌdē ˌen ˈā/
noun
- 1. a self-replicating material that is present in nearly all living organisms as the main constituent of chromosomes. It is the carrier of genetic information.
4 days ago · DNA, organic chemical of complex molecular structure found in all prokaryotic and eukaryotic cells. It codes genetic information for the transmission of inherited traits. The structure of DNA was described in 1953, leading to further understanding of DNA replication and hereditary control of cellular activities.
- The Editors of Encyclopaedia Britannica
- What does DNA do?Deoxyribonucleic acid (DNA) is an organic chemical that contains genetic information and instructions for protein synthesis. It is found in most ce...
- What is DNA made of?DNA is made of nucleotides. A nucleotide has two components: a backbone, made from the sugar deoxyribose and phosphate groups, and nitrogenous base...
- Who discovered the structure of DNA?The discovery of DNA’s double-helix structure is credited to the researchers James Watson and Francis Crick, who, with fellow researcher Maurice Wi...
- Can you edit DNA?Gene editing today is mostly done through a technique called Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR), adopted from a bac...
- What’s the difference between DNA and RNA?DNA is the master blueprint for life and constitutes the genetic material in all free-living organisms. RNA uses DNA to code for the structure of p...
Deoxyribonucleic acid ( / diːˈɒksɪˌraɪboʊnjuːˌkliːɪk, - ˌkleɪ -/ ⓘ; [1] DNA) is a polymer composed of two polynucleotide chains that coil around each other to form a double helix. The polymer carries genetic instructions for the development, functioning, growth and reproduction of all known organisms and many viruses.
- Overview
- For more information about DNA:
- Topics in the Cells and DNA chapter
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DNA, or deoxyribonucleic acid, is the hereditary material in humans and almost all other organisms. Nearly every cell in a person’s body has the same DNA. Most DNA is located in the cell nucleus (where it is called nuclear DNA), but a small amount of DNA can also be found in the mitochondria (where it is called mitochondrial DNA or mtDNA). Mitochondria are structures within cells that convert the energy from food into a form that cells can use.
The information in DNA is stored as a code made up of four chemical bases: adenine (A), guanine (G), cytosine (C), and thymine (T). Human DNA consists of about 3 billion bases, and more than 99 percent of those bases are the same in all people. The order, or sequence, of these bases determines the information available for building and maintaining an organism, similar to the way in which letters of the alphabet appear in a certain order to form words and sentences.
DNA bases pair up with each other, A with T and C with G, to form units called base pairs. Each base is also attached to a sugar molecule and a phosphate molecule. Together, a base, sugar, and phosphate are called a nucleotide. Nucleotides are arranged in two long strands that form a spiral called a double helix. The structure of the double helix is somewhat like a ladder, with the base pairs forming the ladder’s rungs and the sugar and phosphate molecules forming the vertical sidepieces of the ladder.
An important property of DNA is that it can replicate, or make copies of itself. Each strand of DNA in the double helix can serve as a pattern for duplicating the sequence of bases. This is critical when cells divide because each new cell needs to have an exact copy of the DNA present in the old cell.
DNA is a double helix formed by base pairs attached to a sugar-phosphate backbone.
Credit: U.S. National Library of Medicine
The National Human Genome Research Institute (NHGRI), a part of the National Institutes of Health (NIH), provides a fact sheet Deoxyribonucleic Acid (DNA) that gives an introduction to this molecule.
StatedClearly offers a video introduction to DNA and how it works.
The New Genetics, a publication of the National Institute of General Medical Sciences, part of the NIH, discusses the structure of DNA and how it was discovered.
A basic explanation and illustration of DNA can be found on Arizona State University's "Ask a Biologist" website.
The Virtual Genetics Education Centre, created by the University of Leicester, offers additional information on DNA, genes, and chromosomes.
An overview of mitochondrial DNA is available from the Neuromuscular Disease Center at Washington University in St. Louis.
•What is a cell?
•What is DNA?
•What is a gene?
•What is a chromosome?
•How many chromosomes do people have?
•What is noncoding DNA?
DNA, or deoxyribonucleic acid, is the hereditary material in humans and almost all other organisms. It is a double helix of nucleotides that stores and transfers information for building and maintaining an organism. Learn more about the structure, function, and replication of DNA from MedlinePlus Genetics.
Aug 14, 2019 · DNA is a molecule that contains the instructions for life, growth, and health. It has a double helix structure of sugar-phosphate backbones and nucleotides. DNA is present in all cells and contains genes, proteins, and DNA repair pathways. Learn more about the structure, function, and importance of DNA.
Aug 24, 2020 · Deoxyribonucleic Acid (DNA) Fact Sheet. Deoxyribonucleic acid (DNA) is a molecule that contains the biological instructions that make each species unique. DNA, along with the instructions it contains, is passed from adult organisms to their offspring during reproduction. Where is DNA found?
DNA is a complex molecule that contains all of the information necessary to build and maintain an organism. It is the primary unit of heredity in organisms of all types. This unit explains the structure, function, and discovery of DNA, as well as its smaller elements and how they are arranged.
DNA is a molecule composed of nucleotides, each with a nitrogenous base, a sugar, and a phosphate group. DNA can form double-stranded helices with complementary base pairing, and its sequence determines the traits of living organisms.
