How do bases pair in DNA?

In DNA, adenine (A) pairs with thymine (T), and cytosine (C) pairs with guanine (G) through hydrogen bonds.

DNA, or deoxyribonucleic acid, is the molecule that carries the genetic instructions for the development, functioning, growth, and reproduction of all known living organisms. It is composed of two strands that twist around each other to form a double helix structure. Each strand is made up of a sequence of nucleotides, which are the basic units of DNA. These nucleotides are composed of a sugar, a phosphate group, and a nitrogenous base. The bases are the parts of the nucleotides that pair up to connect the two strands of the DNA.

The bases in DNA are adenine (A), thymine (T), cytosine (C), and guanine (G). These bases pair up in a very specific way, known as complementary base pairing. Adenine always pairs with thymine, and cytosine always pairs with guanine. This is due to the shape and structure of the bases, which allow them to form hydrogen bonds with their complementary base. Adenine and thymine can form two hydrogen bonds, while cytosine and guanine can form three.

This specific base pairing is crucial for the structure and function of DNA. It ensures that the DNA strands are held together stably, and it allows the genetic information to be accurately copied when cells divide. When a cell divides, the DNA strands separate, and new strands are formed based on the sequence of bases in the original strands. Because of the specific base pairing, each new DNA molecule is an exact copy of the original. This is how genetic information is passed on from cell to cell, and from generation to generation.