Illustration of DNA
- A molecular model
- 1 hydrogen
- 2 oxygen
- 3 carbon in the helical phosphate ester chains
- 4 carbon and nitrogen in the cross-linked purine and pyrimidine bases
- 5 phosphorus
- B double helix
DNA
noun
: any of various nucleic acids that are usually the molecular basis of heredity, are constructed of a double helix held together by hydrogen bonds between purine and pyrimidine bases (see base entry 1 sense 6b) which project inward from two chains containing alternate links of deoxyribose and phosphate, and that in eukaryotes are localized chiefly in cell nuclei compare recombinant dna
Examples of DNA in a Sentence
Recent Examples on the Web
James Watson, who co-discovered the double-helix structure of DNA in 1953, has died at age 97.
—
Sophia Compton, FOXNews.com, 8 Nov. 2025
Under the rule, the agency could ask for facial images, iris scans, finger and palm prints, voice prints and even DNA.
—Jude Joffe-Block, NPR, 8 Nov. 2025
In May, more than a decade after the fingerprint match, investigators again looked at Wayne’s clothes for a DNA sample, and the Colorado Bureau of Investigation found and tested DNA on Wayne’s jeans that had a high likelihood of belonging to Saathoff.
—Katie Langford, Denver Post, 8 Nov. 2025
Using what was known about biology at the time and X-ray images, the two determined that DNA had a double-helix structure - like a twisted ladder, with each rung made up of a pair of chemicals.
—Reuters, USA Today, 7 Nov. 2025
See All Example Sentences for DNA
Examples are automatically compiled from online sources to
show current usage.
Read More
Opinions expressed in the examples do not represent those of Merriam-Webster or its editors.
Send us feedback.
Sophia Compton, FOXNews.com, 8 Nov. 2025
Under the rule, the agency could ask for facial images, iris scans, finger and palm prints, voice prints and even DNA.
—Jude Joffe-Block, NPR, 8 Nov. 2025
In May, more than a decade after the fingerprint match, investigators again looked at Wayne’s clothes for a DNA sample, and the Colorado Bureau of Investigation found and tested DNA on Wayne’s jeans that had a high likelihood of belonging to Saathoff.
—Katie Langford, Denver Post, 8 Nov. 2025
Using what was known about biology at the time and X-ray images, the two determined that DNA had a double-helix structure - like a twisted ladder, with each rung made up of a pair of chemicals.
—Reuters, USA Today, 7 Nov. 2025
See All Example Sentences for DNA
Cite this Entry
“DNA.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/DNA. Accessed 11 Nov. 2025.
Copy CitationKids Definition
DNA
noun
: any of various nucleic acids that are located especially in cell nuclei, are usually the chemical basis of heredity, and are composed of two nucleotide chains held together by hydrogen bonds in a pattern resembling a flexible twisted ladder compare rna
Medical Definition
DNA
noun
: any of various nucleic acids that are usually the molecular basis of heredity, are constructed of a double helix held together by hydrogen bonds between purine and pyrimidine bases which project inward from two chains containing alternate links of deoxyribose and phosphate, and that in eukaryotes are localized chiefly in cell nuclei
called also deoxyribonucleic acid
see recombinant dnaLove words? Need even more definitions?
Merriam-Webster unabridged
Share