Currently, genetics is very relevant in the scientific fields for research. The impetus for its development was the well-known teaching of Charles Darwin on the discreteness of heredity, natural selection and mutational changes due to the transmission of the bearing genotype. Having begun its development at the beginning of the last century, genetics, as a science, has reached a wide scale, while the methods of studying human genetics are currently one of the main areas of study of both human nature and wildlife in general.
Consider the fundamental methods of research on genetics that are currently known.
Genealogical methods for studying human genetics are the analysis and determination of typical gene structures during inheritance in pedigrees. The results and information are used to prevent, prevent and identify the likelihood of the studied trait in the offspring - hereditary diseases. The type of inheritance can be autosomal (the manifestation of a trait is possible with equal probability in persons of both sexes) and linked to the chromosomal sexual row of the carrier.
The autosomal method, in turn, is divided into autosomal dominant inheritance (the dominant allele can be realized in both the homozygous and heterozygous state) and autosomal recessive inheritance (the recessive allele can be realized only in the homozygous state). With this type of inheritance, the disease manifests itself through several generations.
Genetically linked inheritance is characterized by localization of the corresponding gene in the homologous and non-homologous regions of the Y or X chromosomes. A hetero- or homozygous woman is determined by the genotypic background, which is localized in the sex chromosomes, but men who have only one X-chromosome row can only be hemizygous. For example, a heterozygous woman can pass the disease by inheritance to both her son and daughters.
The biochemical method for the study of genetics is determined by the study of hereditary diseases transmitted as a result of gene mutations. Such methods of studying human genetics reveal hereditary metabolic defects by determining the structures of protein, enzymes, carbohydrates and other metabolic products that remain in the extracellular fluid of the body (blood, sweat, urine, saliva, etc.).
Twin methods for studying human genetics find out the hereditary condition of the studied signs of the disease. Identical twins (a full-fledged organism develops from two or more crushed parts of a zygote at an early stage of its development) have the identical genotype, which allows one to identify differences as a result of the external influence of the environment on the human phenotype. Multiple twins (fertilization of two or more eggs) have the genotype of people related to each other, which allows us to assess the environmental and hereditary factors in the development of the human genotypic background.
The cytogenetic method for the study of genetics is used to study the morphology of chromosomes and the norm of the karyotype, which makes it possible to diagnose hereditary diseases at the chromosomal level, as well as to investigate the mutagenic effect of chemicals, pesticides, drugs, etc., when identifying genomic and chromosome mutations. This technique is widely used in the analysis and subsequent identification of hereditary anomalies of the body before the birth of a child. Prenatal diagnosis of amniotic fluid makes a diagnosis in the first trimester of pregnancy, which makes it possible to decide on termination of pregnancy.