Genetics

Genetics

Genetics is a science, and therefore as such, involves "a certain knowledge of things by their principles and causes." So ... What are these things that as a science studying genetics?, Then, the "biological inheritance" and "Changes." And, its principles and causes, are the "laws and principles" governing the "similarities" and "differences" between individuals of the same "species".Ddesglosar try defining genetic explanatory way, and so go up one by one the steps that lead to greater complexity within the same, which is the "manipulation". First, it is necessary to leave it for granted as clear a concept as simple, but is giving up, and then result in as many concepts. AI to speak of the characteristics pertaining to all living matter, it is said that "every living thing arises from another like him", that is, to have "characters" like those of its parent. And then what do we mean by "character"? It's every quirk, every feature, either morphological (shape), functional, biochemical (some authors also include psychological traits) that provides a biological individual.And these "characters" or features do belong to the same "species". ("Species" is a term that, according to the Dictionary of the Royal Spanish Academy, refers to "the set of things similar to each other, having one or more characters in common with each other").So far everything points to the genetic studies similar characters which are transmitted from parents to children, those who make them look like each other. But it happens that also have characters that are not similar, varying, and which in this science are called "variations", and are also transmitted genetically, or are influenced by the environment, which is called " paratype ".What is still dark within this definition, is how they are transmitted from one generation to another, these "characters" and these "variations" appear this is where the concept of "gene", a term which derives the name of this exciting science, which is genetics.

  

The Genetics after Mendel: chromosome theory of inheritance A beginning of this century, when techniques for the study of the cell were sufficiently developed, it was determined that the genes were formed by deoxyribonucleic acid (DNA) and also were within structures that appeared in the cytoplasm just before each cell divisi6n process. These structures are the denomin6 chromosomes, a term that means "colored bodies" by the intensity with which set certain colors to be dyed to be visible under the microscope. Besides these appeared was repeated in the cell forming a certain number of pairs of homologous chromosomes characteristic of each species, one of which was inherited from the father and the other from the mother. Also it was found that the number of pairs of chromosomes did not depend on the complexity of living. Thus, for example, in man there were 23 pairs of chromosomes, whereas in a plant such as wheat could be up to 28 pairs.

Based on these findings and studies conducted in 1906 by the American zoologist Thomas H. Morgan on the chromosomes of the fruit fly (Drosophila melanogaster), we could develop the theory of heredity cromos6mica which stated unequivocally physical localizac16n of genes in the cell. Thanks to this theory it could also give a final explicaci6n to cases where accuracy is not met Mendel's laws as above.Similar to Mendel, Morgan dedic6 a systematic way across different varieties of fruit flies. These flies they offered many advantages over the peas as they have a very short life cycle, produce large offspring, are easy to grow, so s6lo have four chromosomes and have hereditary characteristics easily observable, such as eye color, presence or absence of wings, etcetera.

 Genes and Disease 

With the help of gene probes, policies, doctors can now track the DNA for defective genes responsible for a multitude of ills.Some of these genes have been exposed, isolated and cloned.Here are some with diseases that trigger.
Hemophilia:Deficiency of normal blood clotting.Is caused by the absence of a protein coagulant.The gene was isolated and cloned in 1984. 
Alcoholism:In March 1990, researchers from Utah, USA, announced that a gene located on chromosome 11 could be involved in the development of the disease.

Huntington's chorea:Neurological disorders such as memory loss and uncontrolled movements.The gene is on chromosome 4. 

Sickle Cell Anemia:Injury caused by defective hemoglobin production, unable to carry oxygen in the blood.The mutant gene was isolated in 1980. 

Mucoviscosidosis:Or cystic fibrosis.Abnormal gene found in 1990 on chromosome 7.It affects thousands of children, causing them respiratory and digestive disorders.Congenital HypothyroidismIt affects about 80 children in Chile, causing profound mental retardation if not detected before six months.

Determinant of Sex:In July 1991, British biologists announced that the sex of the embryo is determined by the activation of a gene found in the male chromosome Y.

X Mental Retardation - Fragile:This is the most common inherited cause of mental retardation.Characterized by a sort of breakdown of one arm of chromosome X.They are looking for the corresponding gene.

Duchenne myopathy:Muscle atrophy that occurs about two years of age and leads to total paralysis. 

Manic - Depression:Also called bipolar disorder, affects about 2 percent of the population.The responsible gene was located in 1987, on chromosome 11. 

Schizophrenia:Affects 1 percent of the population.In 1989, psychiatrists at the University of London found the gene of madness in a region of chromosome 5.Lesch NyhanBlindness and paralysis.Occurs at a frequency of 1 in 3000 in the Jewish populations originating in Central Europe.Gene cloned in 1980.ADA deficiencyThere are 100 reported cases in the world, gene therapy, ethics to point to correct the gene.Congenital MalformationsThe risk of a pregnant woman has a child with a malformation gene, tica at birth is four percent.Among the cases m s common are:

Hydrocephalus:Excessive size of the head due to excessive accumulation of fluid inside the skull.

Microcephaly:Generally small and misshapen head, caused by an underdevelopment of the braincase.

Cleft Lip:Presence in the newborn of a cleft lip.

Imperfect Year:Deformity known as imperforate. The baby born without anus.Spina Bifida:Neural tube defect is an abnormality in the closure of one or more vertebra

             

Bibliography

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