Twentieth Century Inventions
Throughout the twentieth century there were several inventions and discoveries, among which we highlight the following:
Airplane. The Wright brothers carefully studied what was known aeronautics so far, reaching their own conclusions. They began their experiments with gliders in 1900, but the December 17, 1903 when they finish building its first aircraft engine with four-cylinder petrol and 12 horses. Piloted by Orville and moving on a railway track was raised three feet and ran head after about 30 meters in 12 seconds, after falling to the ground, depending on the version of the interested parties and their eyewitnesses. In 1905, Wright traveled a little over 40 miles, flying for 30 minutes without touching the ground. Later, scientists such as Henri Farman, improved the brainchild of brothers Wright.
Other inventions:
Penicillin. is an antibiotic that revolutionized modern medicine. The use of this substance can treat various diseases, well into the twentieth century, is considered incurable. Admittedly, the fact that it is possible to use penicillin in the present is not due solely to Alexander Fleming, but was the result of efforts by various researchers. The British bacteriologist, discovered the antibiotic in 1928, studying a bacterial culture that had a state lysis due to accidental contamination with a fungus. In fact, initiated the era of penicillin antibiotics, substances that have increased the life expectancy rates in virtually all the world. In fact, the model of preparation of antibiotics derived from penicillin.
structure of DNA. In the fifties, the field of biology was convulsed by the development of the model of the structure of DNA. James Watson and Francis Crick in 1953 showed that consists of a double helix formed by two chains.
DNA is a nucleic acid consisting of nucleotides. Each nucleotide consists of three components: a sugar: deoxyribose in this case (in the case of RNA, or ribonucleic acid, a sugar that is a ribose), a phosphate and a nitrogenous base.
If only the sugar molecule is attached to the nitrogenous base is then called a nucleoside.
nitrogenous bases that are part of DNA are: adenine (A), guanine (G), cytosine (C) and thymine (T). These form hydrogen bonds between them, respecting strict complementarity: A only pairs with T (and vice versa) through two hydrogen bonds, and G only with C (and vice versa) by 3 hydrogen bonds.
Source:
http://www.kalipedia.com/geografia-peru/tema/cronologias-principales-inventosdescubrimientos.html?x1 = & x = 20070417klpgeogra_160.Kes 20070417klpgeogra_1.Res
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