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Discovery: Natural Selection
Charles Darwin wrote “On the Origin of Species by Means of Natural Selection, or the Preservation of Favored Races in the Struggle for Life.” -
DIscovery: Materials in Nucleos
Ernst Haeckel; Heredity materials was in the nucleus -
Discovery: Heredity Transmitted in Units
Gregor Mendel’s experiments on peas demonstrate that heredity is transmitted in discrete units. The understanding that genes remain distinct entities even if the characteristics of parents appear to blend in their children explains how natural selection could work and provides support for Darwin’s proposal. -
Discovery: DNA Isolated
Frederick Miescher isolates DNA from cells for the first time and calls it “nuclein”. -
Discovery: Material in the Nucleos
The material in the nucleus was determined to be a nucleic acid.
The experiments of Ernst Haeckel proved that the genetic material is indeed located in the nucleus. -
Discovery: Genetic Material in the Nucleos
The experiments of Ernst Haeckel proved that the genetic material is indeed located in the nucleus. -
Cut DNA Mulecules
Isolated the first restriction enzyme, HindII, that could cut DNA molecules within specific recognition sites. Hamilton Smith. -
First account of Mitosis
Schneider provided the first account of mitosis. -
Theory of heredity
Forwarded ¨strip¨ theory of heredity. -
DIscovery: Cause of failure of beer formation
Louis Pasteur found the cause of failure of beer formation was microbes. -
Discovery: Mitosis Described
Walter Flemming describes chromosome behavior during animal cell division. He stains chromosomes to observe them clearly and describes the whole process of mitosis in 1882. -
Discovery: The mitochondria
Kolliker discovered the mitochondria -
Discovery: lamp-brush chromosome
Discovered lamp-brush chromosome -
Develop of: the ¨Idioplasm theory¨
Nageli developed the ¨Idioplasm theory¨ -
Rename of nuclein and nucleic acid
Nageli developed the ¨Idioplasm theory¨ -
Discovery: ¨X-body¨
Henking discovered and termed ¨X-body¨ -
DNA
Altman coined ¨DNA¨ -
Discovery: Viruses
Beijernick discovered viruses. -
Discovery: Rediscovery of Mendel’s work
Botanists DeVries, Correns, and von Tschermak independently
rediscover Mendel’s work while doing their own work on the
laws of inheritance. The increased understanding of cells and
chromosomes at this time allowed the placement of Mendel’s abstract ideas into a physical context. -
Discovery: Chromosome Theory of Inheritance
Walter Sutton observes that the segregation of chromosomes during meiosis matched the segregation pattern of Mendel’s -
Discovery: Orderly Inheritance of Disease
A British physician, Archibald Garrod, observes that the disease alkaptonuria is inherited according to Mendelian rules. This disease involves a recessive mutation, and was among the first conditions ascribed to a genetic cause. -
homologous chromosomes are the same size
Nettie Stevens observed in Tenebrio beetles that all pairs of homologous chromosomes are the same size, except for one pair which determines sex X, Y -
Discovery: The Word Gene is Coined
Wilhelm Johannsen coins the word “gene” to describe the Mendelian unit of heredity. He also uses the terms genotype and phenotype to differentiate between the genetic traits of an individual and its outward appearance. -
Fly genetics and linkage
Thomas H. Morgan went on to make many important discoveries in fly genetics and linkage analysis that apply to all diploid organisms. -
Discovery: sex-linked trait
US scientist Thomas Hunt Morgan is the first to discover a sex-linked trait, while studying the fruit fly Drosophila. The trait for eye colour, on the X chromosome, is also the first gene to be traced to a specific chromosome -
Discovery: Chromosomes Carry Genes
Thomas Hunt Morgan and his students study fruit fly chromosomes. They show that chromosomes carry genes, and also discover genetic linkage. -
Discovery: Types of Nucleid acid
Fuelgen discovered types of Nucleic acid. -
Discovery: One Gene, One Enzyme Hypothesis
George Beadle and Edward Tatum’s experiments on the red bread mold, Neurospora crassa, show that genes act by regulating distinct chemical events. They propose that each gene directs the formation of one enzyme -
Discovery: DNA Has a Regular Periodic Structure
William Astbury, a British scientist, obtains the first X-ray diffraction pattern of DNA, which reveals that DNA must have a regular periodic structure. He suggests that nucleotide bases are stacked on top of each other. -
Discovery: DNA Transforms Cells
Oswald Avery, Colin MacLeod, and Maclyn McCarty show that DNA (not proteins) can transform the properties of cells -- thus clarifying the chemical nature of genes. -
Discovery: Jumping Genes
Barbara McClintock, using corn as the model organism, discovers that genes can move around on chromosomes. This shows that the genome is more dynamic than previously thought. These mobile gene units are called transposons and are found in many species. -
Discovery: Genes Are Made of DNA
Alfred Hershey & Martha Chase show that only the DNA of a virus needs to enter a bacterium to infect it, providing strong support for the idea that genes are made of DNA -
Discovery: DNA Double Helix
Francis H. Crick and James D. Watson described the double helix structure of DNA. They receive the Nobel Prize for their work in 1962. -
Discovery: 46 Human Chromosomes
Joe Hin Tjio defines 46 as the exact number of chromosomes in
human cells. -
Discovery: DNA copying enzyme
Arthur Kornberg and colleagues isolated DNA polymerase, an enzyme that would later be used for DNA sequencing. -
Discovery: Cause of Disease Traced to Alteration
Vernon Ingram discovers that a specific chemical alteration in a hemoglobin protein is the cause of sickle cell disease. -
Discovery: Semiconservative Replication of DNA
Matthew Meselson and Franklin Stahl demonstrate that DNA replicates semiconservatively: each strand from the parent DNA molecule ends up paired with a new strand from the daughter generation. -
Discovery: Chromosome Abnormalities Identified
Jerome Lejeune and his colleagues discover that Down Syndrome is caused by trisomy 21. There are three copies, rather than two, of chromosome 21, and this extra chromosomal material interferes with normal development. -
Discovery: First Screen for Metabolic Defect in Newborns
Robert Guthrie develops a method to test newborns for the metabolic defect, phenylketonuria (PKU). -
Discovery: mRNA Ferries Information
Sydney Brenner, François Jacob and Matthew Meselson discover that mRNA takes information from DNA in the nucleus to the protein-making machinery in the cytoplasm. -
Discovery: Genetic Code Cracked
Marshall Nirenberg and others figure out the genetic code that allows nucleic acids with their 4 letter alphabet to determine the order of 20 kinds of amino acids in proteins. -
Discovery: First Restriction Enzyme Described
Scientists describe restriction nucleases, enzymes that recognize and cut specific short sequences of DNA. The resulting fragments can be used to analyze DNA, and these enzymes later became an important tool for mapping genomes. -
Discovery: First recombinant DNA
Scientists produce recombinant DNA molecules by joining DNA from different species and subsequently inserting the hybrid DNA into a host cell, often a bacterium. -
Discovery: First animal gene cloned
Researchers fuse a segment of DNA containing a gene from the African clawed frog Xenopus with DNA from the bacterium E. coli and placed the resulting DNA back into an E. coli cell. There, the frog DNA was copied and the gene it contained directed the production of a specific frog protein. -
Discovery: DNA Sequencing
Two groups, Frederick Sanger and colleagues, and Alan Maxam and Walter Gilbert, both develop rapid DNA sequencing methods. The Sanger method is most commonly employed in the lab today, with colored dyes used to identify each of the four nucleic acids that make up DNA. -
Discovery: First Genetic Engineering Company
Herbert Boyer founds Genentech. The company produces the first human proteinin a bacterium, and by 1982 markets the first recombinant DNA drug, human insulin. -
Discovery: Introns Discovered
Richard Roberts’ and Phil Sharp’s labs show that eukaryotic genes contain many interruptions called introns. These non- coding regions do not directly specify the amino acids that make protein products. -
Discovery: First Transgenic Mice and Fruit Flies
Scientists successfully add stably inherited genes to laboratory animals. The resulting transgenic animals provide a new way to test the functions of genes. -
The international Human Genome Project begins
The international Human Genome Project begins, with the goal of sequencing the entire human genetic code. Gene therapy is used successfully for the first time, to treat a four-year-old girl with the rare hereditary immune disorder adenosine deaminase deficiency -
Gnetically modified pet
A tropical fish that fluoresces bright red becomes the first genetically modified pet to go on sale in the US -
Structure of telomerase decoded
Structure of telomerase, an enzyme that conserves the ends of chomosomes, was decoded -
Experiments with mice
Experiments with mice showed that azacytidine treatment enhanced the responsiveness of tumors to anti–CTLA-4 therapy. -
Mutation
Rare mutation of gene called Serpine 1 discovered to protect against biological ageing process by Baldridge.