5.1 Introduction of DNA

The DNA — the deoxyribonucleic acid: the heredity's molecule (the double helix — the Watson- and-Crick discovery); the genome's code (the 3-billion base pairs; the 99.9% shared — the 0.1% unique); the forensic's regions (the non-coding STRs — the repeating units' variation between persons); the cell's sources (the nucleus's DNA — almost every cell; the mitochondria's mtDNA — the maternal line).