Dna

These are the basic building blocks, each consisting of a sugar, a phosphate, and one of four nitrogenous bases.

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 These are the basic building blocks, each consisting

The National Human Genome Research Institute defines DNA as a , a shape resembling a twisted ladder. The "rungs" are formed by pairs of bases

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 Genetic Code

The "sides" of the ladder are made of alternating sugar (deoxyribose) and phosphate groups.

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