What is DNA?

The smaller units that make up DNA are called nucleotides, which are key to forming the double helix. Each nucleotide has three components.

DNA carries all genetic information and contains the instructions that make an individual unique. It stands for deoxyribonucleic acid and is found in nearly all cells.

There are four chemical bases in DNA: adenine (A), thymine (T), cytosine (C), and guanine (G). They always bond specifically: A pairs with T, and C pairs with G. This base pairing rule is crucial for understanding molecular tests in clinical genetics.

The DNA molecule consists of two single strands that bind together to form a double helix, resembling a twisted ladder. DNA is a polymer, meaning it's made of many smaller units.

Two components, a sugar molecule (deoxyribose) and a phosphate, bond to form the backbone (sides of the DNA ladder). The rungs of the ladder are made of weakly bonded chemical bases.