[[Image:FirstSketchOfDNADoubleHelix.jpg|right|thumb|160px|Francis Crick's first sketch of a DNA double helix.]]
=== MolecularМолекул geneticsгенетик ===
AlthoughХромосом chromosomesнь wereгениүдийг knownагуулдаг toмөн containхромосом genes,нь chromosomesпротейн wereболон composedДНХ ofхоёулангаас bothнь proteinбүрэлддэг andболохыг DNAмэддэг —байсан itч wasчухам unknownаль whichнь wasудамшилын criticalзүй forтогтолд heredityчухал orнөлөөтөй howэсвэл theхэрхэн processудамших occurred.процесс Inявагддаг 1928,болох [[Frederickнь Griffith]]тодорхойгүй publishedбайсан hisюм. discovery1928 ofонд the[[Фредерик phenomenonГриффит]] ofөөрийн нээсэн [[TransformationХувиралт (geneticsгенетик)|transformationхувирах]] (seeүзэгдлийн тухай хэвлүүлсэн ([[Griffith'sГриффитийн experimentтуршилт]]ыг үзнэ үү.);. sixteenҮүнээс years16 later,жилийн inдараа 1944, онд [[OswaldОсвальд TheodoreТеодор AveryАвери]], [[ColinКолин McLeodМаклеод]] and, [[MaclynМэклин McCartyМаккарти]] usedнар thisэнэхүү phenomenonүзэгдлийг toашиглан isolateхувиралтанд andчухал identifyүүрэгтэй theбайдаг moleculeмолекул responsible for transformation asбуюу [[DNAДНХ]]-г тусгаарлаж, илрүүлж чадсан байна.<ref name=Avery_et_al>{{cite journal| author=Avery OT, MacLeod CM, and McCarty M| title=Studies on the Chemical Nature of the Substance Inducing Transformation of Pneumococcal Types: Induction of Transformation by a Desoxyribonucleic Acid Fraction Isolated from Pneumococcus Type III| journal=Journal of Experimental Medicine| year=1944| volume=79| issue=1| pages=137-58}}[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=33226 35th anniversary reprint available]</ref> The [[Hershey-Chase experiment]] in 1952 identified DNA (rather than protein) as the genetic material of viruses, further evidence that DNA was the molecule responsible for inheritance.
[[James D. Watson]] and [[Francis Crick]] resolved the structure of DNA in 1953, using the [[X-ray crystallography]] work of [[Rosalind Franklin]] that indicated the molecule had a helical structure. Their double-helix model paired a sequence of nucleotides with a "complement" on the other strand. This structure not only provided a physical explanation for information contained within the order of the nucleotides, but also a physical mechanism for duplication through separation of strands and the reconstruction of a partner strand based on the nucleotide pairings. Although the structure explained the process of inheritance, it was still unknown how DNA influenced the behavior of cells. In the following years many scientists sought to understand how DNA controls the process of [[protein]] production within [[ribosome]]s, eventually discovering the transcription of DNA into [[messenger RNA]] and uncovering the [[genetic code]] which links the nucleotide sequence of [[messenger RNA]] to the [[amino acid]] sequence of protein.
