Mutations occurring in the body, leading to the formation of certain abnormalities.Depending on in which cells and at what stage they occur, may manifest genetic variation, i.e.such changes are transmitted, followed by hereditary cells.Changes are subject to certain signs of the body, depending on the genotype.They can persist for generations, and in some cases there is an accumulation of such deviations.
Hereditary variability can be expressed in concrete transformations serious enough to immediately identify them.Albinism is an example of the body's genetic mutations and changes here also include the lack of tail or horns pets and other similar signs.The vegetation similar phenomenon also happens - deviations in size or petals plant height, other obvious abnormalities.All this is a consequence of mutations and is included in the concept of genetic changes in the body.
Mechanisms of
In any group of individuals that coexist within a certain period of time, formed a spontaneous mutation.They are combined at random on the basis of existing hereditary traits.The greater the deviation, the greater the likelihood of the emergence of new changes that further depart from the norm.
mutations occur during cell formation.At the stage of gamete fusion gene recombination occurs, which is the main cause of variability.The reason may be a discrepancy of chromosomes or their random combination during meiosis and fertilization.Because of the manifestations at this early stage is formed by genetic variation.
However, mutations do not occur spontaneously or by chance, they are due to the influence of certain factors.Mutagens can be radiation exposure, biological or viral effect chemicals.
If the cell in which the mutation occurred, retains the ability to reproduce, it is likely that genetic variation is formed.Changes may be gene, genomic or chromosomal depending on where they occur.
Mutations in evolution
Hereditary variability in the course of evolution have a marked effect on the body.Its value is large enough, and the first time this phenomenon and its mechanisms began to be studied in the 18th century.
Charles Darwin said that every organism is subject to individual variability.Its main characteristics he called an accident, the relative rarity and non-directional in nature.This significantly complicates the prediction process or attempt any predictions.
However, mutations also lead to the formation of a reserve of genetic variation, the formation of different genotypes.However, naturally a function basically performs combinative variability - during sexual reproduction occurs recombination of chromosomes.This changes the compatibility of the genes and their interaction in the genotype, but the genes themselves do not change, therefore there is no abnormality.
These processes help to better understand how genetic variation and Modification.From an evolutionary perspective value individual variation.When it comes to the manifestation of genetic changes, it takes into account not only the presence of abnormal genes, but their combination with other genes belonging to the genotype, moreover, may, anyway, to influence the environmental conditions and the direct development of the organism.
On the one hand, it is important accurate transmission of genetic material from one generation to another, but on the other hand, conservation of the information contained in the genes can be extremely harmful to the organism.
