Human cloning. Conceptual computer artwork of babies emerging from a tunnel, representing human cloning. Human eggs (blue spheres), the face of a man by the Italian artist Leonardo da Vinci (1452- 1519) and a DNA (deoxyribonucleic acid) double helix (grey, upper centre) are seen in the back- ground. A human clone is a person whose genetic material, or DNA, is identical to that of another human being. Human cloning is theoretically capable of producing a limitless number of genetically-identical people, by replacing DNA present in a human egg with adult DNA. DNA is comprised of two spiralling strands (grey) that contain chemical units called nucleotides.