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.

Slipped-strand nucleotide mispairing can generate variation in gene expression. Illegitimate base pairing in regions of repetitive DNA during replication, coupled with inadequate DNA mismatch ...

This is known as the base-pairing rule. A nucleotide consists of 1 phosphate, 1 sugar and 1 base. Each individual's DNA is unique. Apart from identical twins, no one shares the same sequence of bases.