What is DNA (Deoxyribonucleic Acid)? Definition, Meaning & Example
A molecule that carries genetic instructions for all known organisms, structured as a double helix of nucleotides.
TL;DR: A molecule that carries genetic instructions for all known organisms, structured as a double helix of nucleotides.
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DNA (Deoxyribonucleic Acid): A molecule that carries genetic instructions for all known organisms, structured as a double helix of nucleotides.
Explanation
DNA is the hereditary material in all living cells. It is composed of four nucleotide bases: adenine, thymine, guanine, and cytosine. These bases pair specifically (A with T, G with C), allowing DNA to replicate accurately. DNA is located in the cell nucleus and in small amounts in mitochondria. The sequence of bases provides instructions for making proteins. Watson and Crick discovered the double helix structure of DNA in 1953, earning them the Nobel Prize. DNA testing is used in forensics, ancestry, and medicine. Understanding DNA is fundamental to modern biology and genetics.
Example
Your DNA contains about 3 billion base pairs organized into 46 chromosomes. This DNA is in almost every cell of your body and determines your traits.
Frequently Asked Questions
What is the structure of DNA?
DNA is a double helix made of two strands of nucleotides twisted around each other. The bases pair specifically: A with T and G with C.
How does DNA carry instructions?
The sequence of bases in DNA carries instructions. Groups of three bases code for amino acids that form proteins.
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