Dictionary
the branch of biology that studies heredity and variation in organisms
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Wikipedia
Genetics (from the Greek language Greek genno !γεννώ = give birth) is the science of genes, heredity, and the variation of organisms. The word genetics was first applied to describe the study of inheritance and the science of variation by English scientist William Bateson in a letter to Adam Sedgwick, dated April 18, 1905.Humans began applying knowledge of genetics in prehistory with the domestication and selective breedingbreeding of plants and animals. In modern research, genetics provides important tools for the investigation of the function of a particular gene, e.g., analysis of genetic interactions. Within organisms, genetic information generally is carried in chromosomes, where it is represented in the DNA sequencechemical structure of particular DNA molecules.Genes encode the information necessary for synthesizing the amino-acid sequences in proteins, which in turn play a large role in determining the final phenotype of the organism. In diploid organisms, a dominant allele on one chromosome will mask the expression of a recessive gene on the other.The phrase to code for is often used to mean a gene contains the instructions about how to build a particular protein, as in ''the gene codes for the protein''.The "one gene, one protein" concept is now known to be simplistic. For example, a single gene may produce multiple products, depending on how its transcription (genetics)transcription is regulated. Genes also code for the nucleotide sequences in messenger RNAm-RNA, transfer RNAt-RNA and ribosomal RNAr-RNA, required for protein synthesis.Genetics determines much (but not all) of the appearance of organisms, including humans, and possibly how they act. Environmental differences and randomnessrandom factors also play a part. TwinMonozygotic ("identical") twins, a clone resulting from the early splitting of an embryo, have the same DNA, but different personalitypersonalities and fingerprints. Genetically-identical plants grown in colder climates incorporate shorter and less-saturated fatty acids to avoid stiffness.
History - mainHistory of genetics In his paper "Versuche uber Pflanzenhybriden" ("Experiments in Plant Hybridization"), presented in 1865 to the Brunn Natural History Society, Gregor Mendel traced the inheritance patterns of certain traits in pea plants and showed that they could be described mathematically. Although not all features show these patterns of Mendelian inheritance, his work suggested the utility of the application of statistics to the study of inheritance. Since that time many more complex forms of inheritance have been demonstrated. The significance of Mendel's work was not understood until early in the twentieth century, after his death, when his research was re-discovered by other scientists working on similar problems.Mendel was unaware of the physical nature of the gene. We now know that genetic information is normally carried in DNA. (Retroviruses, including influenza, oncoviruses and HIV, and many plant viruses, store their genetic information in RNA.) Manipulation of DNA can in turn alter the inheritance and features of various organisms.
Timeline of notable discoveries - :1859 Charles Darwin publishes ''The Origin of Species'':1865 Gregor Mendel's paper, ''Experiments on Plant Hybridization'':1903 Chromosomes are discovered to be hereditary units:1905 British biologist William Bateson coins the term "genetics" in a letter to Adam Sedgwick:1910 Thomas Hunt Morgan shows that genes reside on chromosomes:1913 Alfred Sturtevant makes the first genetic map of a chromosome:1918 Ronald Fisher publishes ''On the correlation between relatives on the supposition of Mendelian inheritance'' - the modern synthesis starts.:1913 Gene maps show chromosomes containing linear arranged genes:1927 Physical changes in genes are called mutations:1928 Frederick Griffith discovers a hereditary molecule that is transmissible between bacteria (see Griffiths experiment):1931 Crossing over is the cause of recombination (see Barbara McClintock and cytogenetics):1941 Edward Lawrie Tatum and George Wells Beadle show that genes code for proteins; see the original central dogma of genetics:1944 Oswald Theodore Avery, Colin McLeod and Maclyn McCarty isolate DNA as the genetic material (at that time called transforming principle):1950 Erwin Chargaff shows that the four nucleotides are not present in nucleic acids in stable proportions, but that some general rules appear to hold (e.g., that the amount of adenine, A, tends to be equal to that of thymine, T). Barbara McClintock discovers transposons in maize:1952 The Hershey-Chase experiment proves the genetic information of phages (and all other organisms) to be DNA:1953 DNA structure is resolved to be a double helix by James D. Watson and Francis Crick:1956 Jo Hin Tjio and Albert Levan established the correct chromosome number in humans to be 46:1958 The Meselson-Stahl experiment demonstrates that DNA is semiconservative replicationsemiconservatively replicated:1961 The genetic code is arranged in triplets:1964 Howard Temin showed using RNA viruses that Watson's central dogma is not always true:1970 Restriction enzymes were discovered in studies of a bacterium, ''Haemophilius influenzae'', enabling scientists to cut and paste DNA:1977 DNA is sequencingsequenced for the first time by Fred Sanger, Walter Gilbert, and Allan Maxam working independently. Sanger's lab complete the entire genome of sequence of Bacteriophage Phi-X174 phageΦ-X174;.:1983 Kary Banks Mullis discovers the polymerase chain reaction enabling the easy amplification of DNA:1985 Alec Jeffreys discovers genetic finger printing.:1989 The first human gene is sequenced by Francis Collins and Lap-Chee Tsui, it encodes the CFTR protein, defects in this gene cause cystic fibrosis :1995 The genome of ''Haemophilus influenzae'' is the first genome of a free living organism to be sequenced:1996 Saccharomyces cerevisiae is the first eukaryote genome sequence to be released:1998 The first genome sequence for a multicellular eukaryote, ''C. elegans'' is released:2001 First draft sequences of the human genome are released simultaneously by the Human Genome Project and Celera Genomics.:2003 (14 April) Successful completion of Human Genome Project with 99% of the genome sequenced to a 99.99% accuracy genoscope.cns.fr
Areas of genetics -
Classical genetics - Main articles Classical genetics, Mendelian inheritanceClassical genetics consists of the techniques and methodologies of genetics that predate the advent of molecular biology. After the discovery of the genetic code and such tools of Clone (genetics)cloning as restriction enzymes, the avenues of investigation open to geneticists were greatly broadened. Some classical genetic ideas have been supplanted with the mechanistic understanding brought by molecular discoveries, but many remain intact and in use, such as Mendelian inheritanceMendel's laws. Patterns of inheritance still remain a useful tool for the study of genetic diseases.
Clinical Genetics - mainClinical genetics Physicians who are trained as Geneticists diagnose, treat, and counsel patients with genetic disorders or syndromes. These doctors are typically trained in a genetics Residency (medicine)residency and/or fellowship. Although many are pediatricians, some are not.
Molecular genetics - mainMolecular genetics Molecular genetics builds upon the foundation of classical genetics but focuses on the structure and function of genegenes at a Molecule molecular level. Molecular genetics employs the methods of both classical genetics (such as hybridization) and molecular biology. It is so-called to differentiate it from other sub fields of genetics such as ecological genetics and population genetics. An important area within molecular genetics is the use of molecular information to determine the patterns of descent, and therefore the correct scientific classification of organisms: this is called molecular systematics.The study of inherited features not strictly associated with changes in the DNA sequence is called epigenetics.Some take the view that life can be defined, in moleculemolecular terms, as the set of strategies which RNA polynucleotides have used and continue to use to perpetuate themselves. This definition grows out of work on the origin of life, specifically the RNA world hypothesis.
Population, quantitative and ecological genetics - Main articles Population genetics, Quantitative genetics, Ecological geneticsPopulation, quantitative and ecological genetics are all very closely related subfields and also build upon classical genetics (supplemented with modern molecular genetics). They are chiefly distinguished by a common theme of studying populations of organisms drawn from nature but differ somewhat in the choice of which aspect of the organism on which they focus. The foundational discipline is population genetics which studies the distribution of and change in allele frequencyallele frequencies of genes under the influence of the four evolutionary forces: natural selection, genetic drift, mutation and migration. It is the theory that attempts to explain such phenomena as adaptation (biology)adaptation and speciation.The related subfield of quantitative genetics, which builds on population genetics, aims to predict the response to selection given data on the phenotype and relationships of individuals. A more recent development of quantitative genetics is the analysis of quantitative trait loci. Traits that are under the influence of a large number of genes are known as quantitative traits, and their mapping to a location on the chromosome requires accurate phenotypic, pedigree and marker data from a large number of related individuals.Ecological genetics again builds upon the basic principles of population genetics but is more explicitly focused on ecologyecological issues. While molecular genetics studies the structure and function of genes at a molecular level, ecological genetics focuses on wild populations of organisms, and attempts to collect data on the ecological aspects of individuals as well as molecular markers from those individuals.
Genomics - mainGenomics A more recent development is the rise of genomics, which attempts the study of large-scale genetic patterns across the genome for (and in principle, all the DNA in) a given species. Genomics depends on the availability of whole genome sequences, and computational tools developed in the field of bioinformatics for analysis of large set of data.
Closely-related fields - The science which grew out of the union of biochemistry and genetics is widely known as molecular biology.The term "genetics" is often widely conflated with the notion of genetic engineering, where the DNA of an organism is modified for some kind of practical end, but most research in genetics is aimed at understanding and explaining the effect of genes on phenotypes and in the role of genes in populations (see population genetics and ecological genetics), rather than genetic engineering.
See also - List of genetics-related topics
See also - Central dogma of molecular biologyGene regulatory networkGenetic counselingGenetic screenGenetic testingList of publications in biology#Genetics Important publications in geneticsList of genetics research organizationsList of geneticists & biochemistsMitochondrial geneticsReprogenetics
Publications - ''Genetics (journal)Genetics''''Journal of Genetics''''Annals of Human Genetics''''Heredity (journal)Heredity''
External links - bookGenetics
Related publications - ''Advanced Genetics''journals.uchicago.edu - ''American Journal of Human Genetics''''Annual Reviews of Genetics''nature.com - ''European Journal of Human Genetics''''genesdev.org - Genes and Development''hmg.oupjournals.org - ''Human Molecular Genetics''''jhered.oupjournals.org - Journal of Heredity''nature.com - ''Nature Genetics''''Nature Reviews Genetics'' (nature.com - journal home)nature.com - ''Nature Genome Gateway''jpharmacogenetics.com - ''Pharmacogenetics''''Journal of Medical Genetics''
Other - jbpub.com - Exploring the Way Life Worksgslc.genetics.utah.edu - Genetic Science Learning Centerjic.bbsrc.ac.uk - Letter to Adam Sedgwick in 1905 from William Batesonornl.gov - The Virtual Library on Geneticsgene-watch.org - Council for Responsible GeneticsGenetics-footer Biology-footer Category:Academic !disciplinesCategory:Genetics!*af:Genetikabn:জিনতত ্ত্বcs:Genetikada:Gene tikde:Genetiket:Geneetikaes:Ge néticaeo:Genetikofr:Génétiq ueko:유전학io:Genetikoid:Ge netikais:Erfðafræðihe:גנ יקהhu:Genetikalt:Genetikal b:Genetikms:Genetiknl:Genetica ja:遺伝学no:Genteknologipl: Genetykapt:Genéticaru:Ген тикаsimple:Geneticssl:Gen etikafi:Perinnöllisyystiedesv :Genetikta:மரபியல th:พันธุศาส ร์tl:Henetikavi:Di? truyền !họctr:Genetikzh:遗传学
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Websites
Chromosome Help-Station
For people with rare chromosome disorders.
http://www.chromosomehelpstation.com/
Research Study on the Cause for Keloid Scars
A research study, conducted by Dr. Reichenberger at the University of Connecticut Health Center, is recruiting individuals or families with keloids to help understand the formation of keloid scars. Keloids are thick, raised, firm, scars that may develop after an injury or surgery and expand over beyond the original margin of the wound for a prolonged period of time. For more information please visit our web site.
http://www.keloids.org/
Max F. Perutz Laboratories
The Max F. Perutz Laboratories at the Campus Vienna Biocenter were established to form a new research institute in the field of biotechnology with groups from the University of Vienna and the Medical University of Vienna.
http://www.mfpl.ac.at/
Art, Science & Biotechnology
In 1999, under the name ‘Meat Factory’, Jan Willem Wartena (1960) started producing art works inspired by clones and the designer organism, since when his work has evolved from abstract organic to transgenic human.
http://www.artxs.org/
GenoTerra
Informational and Analytical Edition of Genetics GenoTerra.ru
http://www.genoterra.ru/
Genetics Online
Publishes the results of original research in genetics, biochemistry and molecular biology. Includes article abstracts. Full text requires subscription.
http://www.genetics.org
Nature
Nature, International weekly journal of science.
http://www.nature.com/
Oak Ridge National Laboratory (ORNL)
ORNL conducts basic and applied research and development to create scientific knowledge and technological solutions.
http://www.ornl.gov/
Human Molecular Genetics Online
Concentrates on full-length research papers covering a wide range of topics in all aspects of human molecular genetics. Subscription required for full-text papers.
http://hmg.oupjournals.org/
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