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Wednesday, September 1, 2010

PowerPoint Presentation on History of Genetic Engineering

PPT On Genetic Engineering


History of Genetic Engineering Presentation Transcript:
1. Genetic engineering is normally taken to mean recombinant DNA technology -- the artificial addition, deletion or rearrangement of sequences of bases in DNA in order to alter the observable form and function of an organism. However, genetic engineering is sometimes referred to as biotechnology and biotechnologists have been quick to point out that mankind has been doing biotechnology ever since the first farmers some 10,000 years ago started to domesticate wild species by selecting seeds of wild plants for cultivation or selectively breeding wild animals. In this history, therefore, we include any artificial intervention in the reproductive process as well as some landmarks in the development of genetics which has made genetic engineering possible. This will include selection procedures old and new which could influence the genetic outcome of a reproductive event, gene therapy and diagnosis as well as cloning, vegetative reproduction and in vitro (test-tube) reproduction procedures.

2. circa 10,000 years ago The beginnings of agriculture: selection of wild grasses and subsequent breeding in cultivation to form the precursors of modern staples such as wheat, rice and maize. A considerable practical knowledge was developed by breeders over the centuries and selection procedures often achieved from a single wild species a huge difference in form and function: e.g. the Great Dane and Chihuahua dog varieties from the wolf. Furthermore, 'unnatural' hybrids -- i.e. creating breeds across species barriers -- were made in ancient times. For instance the mule, a cross between a jackass or male donkey and a mare has been used as a pack animal in Europe for at least 3,000 years.

3. 1627 Francis Bacon foretells genetic engineering and terminator technology.

4. 1859 Charles Darwin published the first edition of The Origin of the Species which amongst other things gives extensive information on the knowledge of breeding at that time. Download The Origin of the Species from either of the two sites below:

5. 1865 Gregor Mendel's publication of his discoveries with the breeding of peas which became the foundation of modern genetics. MendelWeb - Origins of classical genetics. 1866 Ernst Haeckel proposes that the cell nucleus is the bearer of an organism's heritable characteristics. 1869 Friedrich Miescher discovers nuclein -- a major component of which is DNA -- in the cell nucleus.

6. 1875 Oscar Hertwig using microscopy observes sea urchin sperm entering the egg and the two nuclei fusing. 1890 Birth of a rabbit from an embryo implanted in the uterus of a surrogate. 1900 Hugo de Vries, Carl Correns & Erich von Tschermak rediscover Mendel's principles.

7. 1902 Walter Sutton & Theodor Boveri propose the chromosome theory of inheritance. Archibald Garrod suggested from studies of alcaptonuria, a disease for which one symptom is the appearance of a black pigment in the urine, that a defective gene gave rise to a defective enzyme (a protein which is a biological catalyst in cell processes). 1910 T. H. Morgan demonstrated that the chromosomes are the concrete entities which carry the genes. (Also Clavin Bridges, 1916) 1913 A.H. Sturtevant constructed a genetic map.

8. 1927 H. J. Muller demonstrated that genetic mutation could be induced by X-rays.

9. 1931 Barbara McClintock and Harriet Creighton demonstrate direct physical recombination by examining maize chromosomes microscopically.

10. For more please refer our PPT. Thanks.

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