Nuclear DNA the bases are held together by hydrogen bonds. Nuclear DNA and mitochondrial DNA differ in many ways, starting with location and structure. Nuclear DNA is located within the nucleus of eukaryote cells and usually has two copies per cell while mitochondrial DNA is located in the mitochondria and contains 100-1,000 copies per cell. The structure of nuclear DNA chromosomes is linear with open ends and includes 46 chromosomes containing 3 billion nucleotides. Mitochondrial DNA chromosomes usually have closed, circular structures, and contain for example 16,569 nucleotides in human. Nuclear DNA is diploid, ordinarily inheriting the DNA from two parents, while
DNA synthesis artificially stimulate the replication of naturally occurring DNA, or to create artificial gene sequences. The process of DNA replication occurs typically as part of cell division, during interphase. A polymerase chain reaction is a form of enzymatic DNA synthesis in the laboratory, using cycles of repeated heating and cooling of the reaction for DNA melting and enzymatic replication of the DNA. Artificial gene synthesis is the process of synthesizing a gene "in vitro" without the need for initial template DNA samples. In 2010 J. Craig Venter and his team were the first to use entirely synthesized DNA to create a