The "rungs" are formed by pairs of bases held together by hydrogen bonds. They follow strict pairing rules: Adenine (A) always pairs with Thymine (T) . Guanine (G) always pairs with Cytosine (C) . The Genetic Code
These are the basic building blocks, each consisting of a sugar, a phosphate, and one of four nitrogenous bases. The "rungs" are formed by pairs of bases
The National Human Genome Research Institute defines DNA as a , a shape resembling a twisted ladder. The Genetic Code These are the basic building
DNA () is the hereditary molecule that carries the genetic "instruction manual" for the development, survival, and reproduction of nearly all living organisms . It functions as a stable repository of information, stored in every cell's nucleus, that dictates physical traits and biological functions. Molecular Structure It functions as a stable repository of information,
The specific sequence of these four bases (A, T, C, and G) creates a biological alphabet that MedlinePlus Genetics compares to letters in a sentence. What is DNA?: MedlinePlus Genetics
The "sides" of the ladder are made of alternating sugar (deoxyribose) and phosphate groups.