Genetics - from ancient times to the present day

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Genetics - field of biology that studies the genes, heredity and the laws and principles of the variation of organisms.In principle, a certain degree of genetic roots can be traced back to the early days of human civilization when man accidentally discovered that living beings can inherit traits from their ancestors and, of course, parents.The benefit of such a fact revealed very quickly, and so appeared as a selective breeding of cereals and animals.However, as modern genetics began in the mid-nineteenth century, with the work of Gregor Mendel.Even despite the fact that the very physical foundations of Mendelian heredity were unknown, he was able to observe that organisms inherit certain traits through special discrete units of heredity.It is these units today and we call genes.

essentially genes - are sites in the DNA, and DNA - a molecule comprised of four different types of nucleotides, which sequence is heritable genetic information of organisms.The genetic code, in turn, is the relationship between nucleotide sequence and amino acid sequence responsible for the protein function.

However, genetics, although it plays an extremely important role in the emergence and development, the operation and behavior of an organism, not only defines, so to speak, "the end result of" development.Except for the genetics involved in this and the conditions in which the development of the organism.Relatively speaking, heredity may play an important role in the formation of, for example, high-growth, but especially the environment, diet, amount of physical activity and even the execution of specific exercises - all of which can significantly affect the above characteristics (growth).

number of diseases can be transmitted at the exact same model.Such diseases are called "hereditary diseases", or disease occurrence and development of which is caused by defects in the cells.This should not be confused polietiologichesky diseases and a narrower group of genetic diseases group.How is the inheritance of genetic diseases?The basis of hereditary diseases is nothing but mutations inheritable information - whether genetic, chromosomal or mitochondrial mutations.Hereditary diseases account for more than six thousand.

According to statistics, about five or six hundred children from newborns is born with a certain genetically determined disease is usually a disease with a genetic predisposition.It should be noted that a number of such illnesses can be attributed to congenital malformations, as well as certain violations in the intellectual development of the child.However, at the same include other genetic diseases which might arise as the first time, and to be inherited from the parents (or one of them).The probability of having a child with this or that genetically caused disease depends on several facts, among which:

  1. age parents.As with age cells accumulate more and more minor mutations, increases with age and risk of having a child with genetic anomalies;

  2. closely link.Relatives can be carriers of the same genes of patients, which clearly adversely affect the offspring;

  3. previously met in the family of genetic abnormality.This may be in the form of a family of chronic diseases, and in the presence of patients already born children;

  4. belonging to certain ethnic groups.

Alas, the best way to treat genetic diseases is their preventive maintenance, which is considered to be consultation genetics and genetic testing - even before conception.