theory of evolution of living organisms



Charles Darwin, the developer of the theory of evolution of living organisms, yet was not able to answer the question of how is securing changes in the structure and function of the body's offspring.Darwin's book came out in the press, when Gregor Mendel in the Czech Republic has set a new experiments, the conclusions of which was the beginning of further development of the science of heredity.

In Germany, at the same time worked as a scientist and zoologist August Weismann, who was able to prove that some properties of the parents passing by inheritance, directly dependent on the ability to send the first of a certain substance.What do you think Weissman, the substance concealed in the chromosomes.

American scientist Thomas M
organ also put a huge amount of experiments.He and his colleagues have designed the basic tenets of the theory of chromosomal inheritance.


How to Open DNA



Biochemist Miescher in 1869 identified a substance having certain properties of the acid.Then the chemist by the name of Levin was able to prove that in the acid secretion has deoxyribose.It is this fact, and gave the name of a molecule of DNA - deoxyribonucleic acid.Levin also identified four nitrogenous bases that form a part of the molecule.

In 1950 biochemist Chargaf conclusion Levin added, when he received the results of tests which showed that the DNA molecule has four bases, two of them are equal in number to the other two.

structure of DNA



In 1953, scientists from Cambridge, Watson and Crick, announced that they discovered the structure of DNA.They found that the DNA molecule - the spiral, which is composed of two chains, which have a base sugar phosphate.It was determined the sequence of the nitrogenous base.That she was a so-called code to transmit genetic information.In 1953 scientists published an article, entitled "The molecular structure of nucleic acids."This article presents the results of studies that showed that DNA is indeed a double helix.

Opening this level has been recognized by scientists around the world and became a "starting point" for further research.In 1962, Watson and Crick received the Nobel for his research prize.