Deoxyribonucleic acid single-copy

With the exception of certain viruses, the blueprint for all organisms is contained in code by deoxyribonucleic acid (DNA), a giant macro-molecule whose structure allows a vast amount of information to be stored accurately. We have all arisen from a single cell, the fertilized ovum containing two sets of DNA (packaged with protein to form chromatin), one set from our mother, resident in the nucleus of the unfertilized ovum, the second set from our father via the successful sperm. Every cell in the adult has arisen from this one cell and (with the exception of the germ cell and specialized liver cells) contains one copy of these original chromosome sets. 

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