DNA is fundamental to the biology of all life on Earth, but how many of us actually know what it is or what it's made of?

DNA consists of four chemical units, called nucleotide bases: adenine (A), thymine (T), guanine (G), and cytosine (C). These bases pair up with each other (A with T and C with G) to form units called ...

A sugar molecule, a base, and a phosphate molecule group together to make up a nucleotide ... Cytosine (C) will "pair" to guanine (G), and adenine (A) will "pair" to thymine (T).

also called base pairs. Two types of base pairing occur: nucleotide A pairs with T, and nucleotide C pairs with G.

One goal of the project was to accurately sequence the 3 billion nucleotide base pairs in the human genome. A second goal was to map and identify all of the human genes present in the DNA sequence.

Each nucleotide consists of alternating sugar and phosphate sections with one of the four different bases attached to the sugar.