Every one of us, except identical twins or clones, has a unique set of DNA, or a genome, which in part is what makes us separate individuals. Inside each of our cells’ nuclei, we have 23 pairs of chromosomes, and one in each pair is inherited from one of our parents. The thread-like chromosomes contain all our genetic information. DNA (deoxyribonucleic acid) molecules make up most of a chromosome and are the genetic material for all cellular organisms and most viruses. They act as the message carriers of chemical sequences governing the production of proteins. Such patterns are the genes, and all together they make up the blueprint of life.