The history of the development of genetics began with the theory of evolution, which was published in 1859 by the English naturalist and traveler Charles Darwin in his book On the Origin of Species.
In 1831, Darwin joined a five-year scientific expedition to study the fossils found in the rocks, evidence of animals that lived millions of years ago. Darwin also noted that the Galapagos Islands maintained their own variety of finches, which were closely related but had minor differences that seemed to be adapted to suit their individual environment.
Upon his return to England, Darwin over the next 20 years proposed the theory of evolution occurring in the process of natural selection. The book On the Origin of Species was the culmination of these efforts, where he argued that living beings are best suited to their environment and are more likely to survive, reproduce, and pass on their characteristics to their offspring. This led to the theory of the gradual change of species over time. His research contains some truths such as the connection between animal and human evolution.
The book that started the history of genetics was highly controversial at the time, as it challenged the dominant view at a time when many people literally thought God created the world in seven days. He also suggested that humans were animals and may have evolved from apes. He noted that after thousands of years of evolution, animals have their bodies adapted to life. If humans evolved from animals over millions of years, certain innate qualities remain today.
1859 - Charles Darwin publishes The Origin of Species.
The science of hereditary variation has led to the development of molecular biology for a deeper understanding of the mechanisms of hereditary variation and the science of genetics.
The initial stage of development of molecular biology
The initial stage of development of molecular biology belongs to the Swiss physiological chemist Friedrich Miescher who in 1869 first identified what he called the "nucleic" nuclei of human white blood cells, which we know today as deoxyribonucleic acid (DNA).
Initially, Friedrich Miescher isolated and characterized the protein components, white blood cells. To do this, he took pus-rich bandages from a local surgical clinic, which he planned to rinse before filtering the white blood cells and isolating their various proteins.
However, in the course of work, I came across a substance that has unusual chemical properties, unlike proteins, with a very high content of phosphorus and resistance to protein digestion. Misher quickly realized that he had discovered a new substance and felt the importance of his discovery. Despite this, it took more than 50 years for the general scientific community to appreciate his work.
1869 Friedrich Miescher isolates "nucleic" acids or DNA
DNA macromolecule provides storage, transmission from generation to generation and implementation of genetic information
The main initial stages in the development of genetics
The main stages in the development of genetics began with the teaching of the synthesis of Darwinism and the mechanisms of the evolution of living things.
In 1866, the unknown monk Austrian biologist and botanist Gregor Mendel was the first person to shed light on the way in which traits are passed down from generation to generation.
Gregor Mendel is now considered the father of genetics.
He enjoyed less fame during his lifetime, and his discoveries were largely not accepted in the scientific community. In fact, he was so ahead of the curve that it took three decades for his discoveries to be taken seriously.
Between 1856 and 1863 Mendel carried out experiments on pea plants, trying to cross and determine the "true" line in a certain combination. He identified seven traits: plant height, pod shape and color, seed shape, flower color and position, and coloration.
He found that when yellow pea and green pea plants were grown together, their offspring were always yellow. However, in the next generation of plants, green peas returned in a 3:1 ratio.
Mendel introduced the terms recessive and dominant in relation to traits in order to explain this phenomenon. So, in the example, the green trait was recessive and the yellow trait was dominant.
1866 - Gregor Mendel discovers the basic principles of genetics
In 1900, 16 years after his death, Gregor Mendel's study of the hereditary traits of peas was finally accepted by the general scientific community.
The Dutch botanist and geneticist Hugo de Vries, the German botanist and geneticist Carl Erich Correns, and the Austrian Erich Czermak-Seisenegg all independently rediscovered Mendel's work and presented hybridization experiments with similar conclusions.
In Britain, the biologist William Bateson became the leading theorist of Mendel's theory, and an enthusiastic group of followers gathered around him. The history of the development of genetics took three decades to sufficiently understand Mendel's theory and find its place in evolutionary theory and introduce the term: genetics as a science that studies hereditary variability.
Ethical problems in the development of medical genetics
Ethical problems in the development of medical genetics have appeared since the beginning of the 1900s, when the science of eugenics (from the Greek - "good kind") was born. The meaning of the science of eugenics is in influencing the reproductive qualities for certain dominant races of people. The science of eugenics is a particularly dark chapter that testifies to the lack of understanding regarding the new discovery at the time. The term "eugenics" was first used around 1883 to refer to the "science" of heredity and breeding.
In 1900, Mendel's theories were rediscovered, who found a regular statistical pattern for characterizing a person as height and color. In the frenzy of research that followed, one thought branched off into the social theory of the science of eugenics. It was a huge popular movement in the first quarter of the 20th century and was presented as a mathematical science that could predict the character traits and characteristics of a human being.
Ethical problems in the development of medical genetics arose when researchers became interested in controlling the reproduction of human beings so that only individuals with the best genes could reproduce and improve the species. This is now being used as a kind of "scientific" racism to convince people that some racial species were superior to others in terms of purity, intelligence, etc. This is indicative of the dangers that come with practicing eugenics science without true respect for humanity in in general.
Many people could see that the discipline was riddled with inaccuracies, assumptions and contradictions, as well as the promotion of discrimination and racial hatred. However, in 1924 the movement received political support when the Immigration Act was passed by a majority in the US House of Representatives and Senate. The law introduced hard quotas on immigration from countries for "inferior" races such as Southern Europe and Asia. When political gain and the convenient science of eugenics joined forces, the ethical problems of the development of medical genetics emerged.
With continued scientific research and the introduction of behaviorism (the science of behavior) in 1913, the popularity of eugenics finally began to decline. The horrors of institutional eugenics in Nazi Germany that came to light during World War II completely destroyed what was left of the movement.
So, from the end of the 19th to the beginning of the 20th century, the history of the development of genetics received the main patterns of the transmission of hereditary traits in plant and animal organisms, which were subsequently applied to humans.
Now there is a science that studies the aging process of the body.
In today's age of integration, it is very difficult to define the boundaries of almost any science. This also applies to genetics. We can of course use the stamped " the science of heredity and variation But this does not convey the whole essence and scope of this discipline. Despite the fact that genetics is present everywhere - medicine, history, forensic science and even sports. And what can we say about modern biology.
However, relatively recently, this young science was almost the most isolated area of biological science. And only in the last third of the last century did its rapid progress begin.
How Genetics Became Comprehensive
A feature of genetics has always been its synthetic methodology, which distinguishes it from the analytical methodology of other areas of biology. So, exploring the object of her study, she did not divide it into parts, but indirectly, observing the whole (the ratio of features during crossings) and, based on mathematics, studied it. Confirmation of the fidelity of her conclusions were living organisms with predicted signs. And how did a separate science come to possibly take center stage in modern biology?
Since the 1950s, another new science, molecular biology, has been rapidly developing. Analytical science is fundamentally opposed to genetics. However, the subjects of these two disciplines overlapped in many ways: they both studied the transmission and implementation of hereditary information, but they moved from opposite directions. Genetics, if I may say so, "outside", molecular biology - "from within".
And finally, at the end of the 20th century, genetics and molecular biology "met", and the speculative objects of genetic research acquired a specific physical and chemical form, and molecular biology became a synthetic science. And it was from that moment that the boundaries of genetics as a science were erased to indistinguishability - it was impossible to determine where molecular biology ends or genetics begins. And to designate the new emerging synthetic science, the name "molecular genetics" appeared.
Where is classical genetics?
The title "classical genetics" began to call the genetics of the premolecular period, together with all its approaches based on the theory of probability and crosses. But along with this title, she was sent to an “honorable retirement”. Classical genetics is a science in which no more discoveries are made, but it is extremely necessary for understanding the basic patterns of heredity and variability, without understanding which many areas of scientific knowledge would not have reached the heights that they have already conquered.
When did genetics begin?
It is customary to say that genetics originated when the Czech Augustinian monk Gregor Mendel conducted his experiments on peas. It is worth noting that the scientific community of that period did not attach importance to the works of Mendel, and they received recognition after more than a dozen years. But scientists have dealt with issues of heredity and variability before him, but their work is very rarely remembered.
So back in the 18th century, botanists began to experimentally study the inheritance of plant traits. It is worth mentioning Joseph Gottlieb Kelreuter, from 1756 to 1761, who worked at the Academy of Sciences in St. Petersburg. It was there that he conducted the first experiments on artificial hybridization of plants, the results of 136 were published.
In experiments with dope, tobacco and cloves, Kelreitor established the equality of "mother" and "father" in the transfer of traits to descendants, and also proved the existence of sex in plants. But his most important contribution to science was a new method of studying heredity - the method of artificial hybridization. Using it, the Frenchmen Augustin Sazhre and Charles Victor Naudin discovered the phenomenon of dominance in the middle of the 19th century. All the accumulated facts required their comprehension. It is in the comprehension of these facts that the main merit of Gregor Mendel lies.
Modern genetics
Modern genetics has already taken a very far step from the classical teachings of Mendel and is becoming increasingly important in the fields of medicine, biology, agriculture and animal husbandry. Modern genetics is primarily molecular genetics. On its basis, the selection of useful microorganisms, plants and animals is carried out. Genetically modified organisms have useful properties that are not characteristic of their relatives from the "wild" nature. For example, the leaves of genetically modified potatoes are inedible for the Colorado potato beetle - the worst enemy of the potato and those who grow it. The number of genetically modified foods consumed by mankind is growing every year.
Given the fact that a huge number of human diseases are genetically determined, it is impossible to overestimate the importance of genetics for medicine. After the human genome was deciphered at the beginning of the 21st century, methods for preventing hereditary pathologies and combating the negative effects of genes are becoming more effective. For example, the likelihood and risk of developing chronic diseases can be predicted long before the birth of a child, and methods are also emerging to minimize this risk.
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Genetics - science of heredity and variability of living organisms mov. All living organisms (systems), regardless of the level of organization, have two alternative properties: heredity and variability. Heredity It manifests itself in the fact that any individual, population or species as a whole strives to preserve their inherent characteristics and properties in a number of generations. This ability of living organisms to give birth to their own kind underlies the maintenance of a certain conservatism of the species. However, the genetic stability of living systems with a sharp and significant change in the environment, which caused an imbalance in the processes of adaptation, can lead to their death, i.e., disappearance. Under such conditions, the safety of living systems is ensured by their ability to lose old features and acquire new ones, i.e. variability. Multiple variants of hereditary changes serve as material for the natural selection of the most adapted and stable life forms.
The birth of genetics as a science is usually associated with the name of G. Mendel, who in the second half of the 19th century. received the first evidence of the material nature of heredity. However, science officially arose in 1900, when G. De Vries, K. Correns and E. Chermak, independently of each other, discovered the laws of G. Mendel for the second time. And the term "genetics" itself was proposed in 1909 by W. Batson.
In genetics, two essential sections can be distinguished: classical genetics And modern. There are a number of stages in the development of classical genetics:
- 1 - the discovery of the basic laws of heredity, the creation of the theory of mutations and the formation of the first ideas about the gene (1900-1910);
- 2 - creation of the chromosome theory of heredity (1910-1920);
- 3 - discovery of induced mutagenesis, obtaining evidence of the complex structure of the gene, birth population genetics(1920-1940);
- 4 - birth genetics of microorganisms, establishing the genetic role of DNA, solving a number of problems in human genetics (1940-1953).
The period of development of modern genetics began with the decoding of the DNA structure by J. Watson and F. Crick in 1953.
Classical genetics at first was a section of general biology, which took an individual as a unit of life and studied the main patterns of inheritance of traits and variability at the level of the organism. With the integration of genetics with such branches of natural science as cytology, embryology, biochemistry, physics, new directions in science arose, and cells of animals and plants, bacteria, viruses, and molecules became objects of study.
Modern genetics is a complex science that includes a number of separate disciplines: animal genetics, plant genetics, biochemical genetics, radiation genetics, evolutionary genetics, etc.
General genetics studies the organization of hereditary material and the general patterns of heredity and variability characteristic of all levels of organization of the living.
Molecular genetics studies the structure of nucleic acids, proteins and enzymes, primary gene defects and their abnormal products; develops methods for mapping chromosomes; solves problems of genetic engineering.
Cytogenetics examines the human karyotype under normal and pathological conditions.
Somatic cell genetics conducts mapping of the human genome using hybridization of cells and nucleic acids.
Immunogenetics studies patterns of inheritance of antigenic specificity and genetic conditioning of immune responses.
Pharmacogenetics explores the genetic basis of drug metabolism in the human body and the mechanisms of hereditary individual response to the administration of drugs.
human genetics studies the phenomena of heredity and variability in human populations, the features of the inheritance of traits in the norm and their changes under the influence of environmental conditions.
population genetics- determines the frequencies of genes and genotypes in large and small populations of people and studies their changes under the influence of mutations, genetic drift, migrations, selection.
Genetics, as an integral part of biology, solves a number of problems:
- 1. The study of the patterns of heredity and variability, the development of methods for their practical use.
- 2. The study of methods of storage and material carriers of information in different organisms (viruses, bacteria, fungi, plants, animals and humans).
- 3. Analysis of the mechanisms and patterns of transmission of hereditary information from one generation of cells and organisms to another.
- 4. Revealing the mechanisms and patterns of realization of hereditary information into specific signs and properties of the organism in the process of ontogenesis.
- 5. The study of the causes and mechanisms of changes in genetic information at different stages of development of the organism under the influence of environmental factors.
- 6. The choice of the optimal system of crossing in breeding work and the most effective method of selection, management of the development of hereditary traits, the use of mutagenesis in breeding.
- 7. Development of measures to protect human heredity from the mutagenic effects of environmental factors.
- 8. Develop ways to correct damaged genetic information.
To solve the above problems, methods have been developed that allow conducting research at different levels of the organization.
hybridological method: allows you to get a versatile quantitative characteristic of the patterns of inheritance, features of the interaction of genes, mechanisms and patterns of hereditary and non-hereditary variability.
Cytological methods: study at the cellular level the dependence of the manifestation of signs on the behavior of chromosomes, variability - on the state of the chromosomal apparatus and other similar problems.
Biochemical methods: allow you to determine the localization of genes that control the synthesis of specific proteins, to find out the mechanisms of regulation of gene activity and the implementation of hereditary information at the molecular level.
Population-statistical method: studies the mechanisms of heredity and variability at the level of communities and groups of individuals, the genetic structure of populations and the nature of the distribution of gene frequencies in them, determines the factors influencing these processes.
Clinical and genealogical method: based on pedigrees, it studies the transmission of a particular trait in a number of generations.
twin method: determines the role of the genotype and environment in the manifestation of the trait.
cytological method: examines the karyotype.
Methods of genetics of somatic cells: study questions of human genetics in the experiment.
Modeling methods: study some issues of genetics, in particular human genetics, using mutant lines of animals with similar disorders, or mathematical models.
Express methods for studying human genetics: Guthrie microbiological inhibitory test; biochemical and microbiological methods; detection of X- and Y-chromatin; dermatoglyphic method.
Methods of prenatal diagnosis of hereditary diseases: determination of alpha-fetoprotein (AFP); ultrasonography (sonography); chorionbiopsy; amniocentesis; fetoscopy.
Meaning of genetics:
- 1. Knowledge of the genetic mechanisms and patterns of formation of the physical and mental sphere of the child, a correct assessment of the role of heredity and external factors, including education, in the process of the formation of his character are necessary for pedagogical specialists.
- 2. Achievements in genetics are used in the study of problems of immunity and transplantation of organs and tissues, in oncology, in the hygienic assessment of the environment, in determining the resistance of microorganisms to drugs, in the production of hormones, enzymes, drugs, in the treatment of hereditary diseases, etc.
- 3. Knowledge of genetics is necessary for a doctor of any specialty and biologists of all profiles to understand the essence of life, the mechanisms of individual development and its disorders, the nature of any disease, a rational approach to the diagnosis, treatment and prevention of diseases.
- 4. The use of the laws of heredity and variability underlies the creation of new highly productive breeds of domestic animals and plant varieties.
- 5. Knowledge of genetics is necessary for the selection of microorganisms that produce antibiotics.
- 6. The use of genetic engineering makes it possible to obtain biologically active substances necessary for a person by biological synthesis in industrial conditions (antibiotics, insulin, interferon, etc.).
Genetics is a science that studies the patterns of transmission of traits from parent to offspring. This discipline also considers their properties and ability to change. In this case, special structures - genes - act as carriers of information. At present, science has accumulated enough information. It has several sections, each of which has its own tasks and objects of research. The most important of the sections: classical, molecular, and
classical genetics
Classical genetics is the science of heredity. This is the property of all organisms to transmit their external and internal signs to offspring during reproduction. Classical genetics also deals with the study of variation. It is expressed in the instability of signs. These changes accumulate from generation to generation. It is only through this variability that organisms can adapt to changes in their environment.
The hereditary information of organisms is contained in genes. Currently, they are considered from the point of view of molecular genetics. Although these concepts arose long before the appearance of this section.
The terms "mutation", "DNA", "chromosomes", "variability" have become known in the process of numerous studies. Now the results of centuries of experiments seem obvious, but once it all started with random crosses. People sought to obtain cows with greater milk yields, larger pigs and sheep with thick wool. These were the first, not even scientific, experiments. However, it was these prerequisites that led to the emergence of such a science as classical genetics. Up until the 20th century, crossbreeding was the only known and available research method. It is the results of classical genetics that have become a significant achievement of the modern science of biology.
Molecular genetics
This is a section that studies all the patterns that are subject to processes at the molecular level. The most important property of all living organisms is heredity, that is, they are able from generation to generation to preserve the main structural features of their body, as well as the patterns of metabolic processes and responses to various environmental factors. This is due to the fact that at the molecular level, special substances record and store all the information received, and then pass it on to the next generations during the process of fertilization. The discovery of these substances and their subsequent study became possible thanks to the study of the structure of the cell at the chemical level. So nucleic acids were discovered - the basis of genetic material.
Discovery of "hereditary molecules"
Modern genetics knows almost everything about nucleic acids, but, of course, this was not always the case. The first suggestion that chemicals could be somehow related to heredity was put forward only in the 19th century. At that time, the biochemist F. Miescher and the biologist brothers Hertwig were studying this problem. In 1928, the Russian scientist N.K. Koltsov, based on the results of research, suggested that all the hereditary properties of living organisms are encoded and placed in giant "hereditary molecules". At the same time, he stated that these molecules consist of ordered links, which, in fact, are genes. It was definitely a breakthrough. Koltsov also determined that these "hereditary molecules" are packed in cells into special structures called chromosomes. Subsequently, this hypothesis was confirmed and gave impetus to the development of science in the 20th century.
The development of science in the 20th century
The development of genetics and further research led to a number of equally important discoveries. It was found that each chromosome in a cell contains only one huge DNA molecule, consisting of two strands. Its numerous segments are genes. Their main function is that they encode information about the structure of enzyme proteins in a special way. But the implementation of hereditary information into certain traits proceeds with the participation of another type of nucleic acid - RNA. It is synthesized on DNA and makes copies of genes. It also transfers information to the ribosomes, where the synthesis of enzymatic proteins occurs. was elucidated in 1953, and RNA - in the period from 1961 to 1964.
Since that time, molecular genetics began to develop by leaps and bounds. These discoveries became the basis of research, as a result of which the patterns of the deployment of hereditary information were revealed. This process is carried out at the molecular level in cells. Fundamentally new information about the storage of information in genes was also obtained. Over time, it was established how the mechanisms of DNA doubling before (replication), the processes of reading information by an RNA molecule (transcription), and the synthesis of protein enzymes (translation) take place. The principles of changes in heredity were also discovered and their role in the internal and external environment of cells was clarified.
Deciphering the structure of DNA
The methods of genetics have been intensively developed. The most important achievement was the decoding of chromosomal DNA. It turned out that there are only two types of chain sections. They differ from each other in the arrangement of nucleotides. In the first type, each site is original, that is, it has uniqueness. The second one contained a different number of regularly repeating sequences. They were called repetitions. In 1973, the fact was established that unique zones are always interrupted by certain genes. A segment always ends with a repeat. This gap encodes certain enzymatic proteins, it is by them that RNA “orients itself” when reading information from DNA.
The first discoveries in genetic engineering
Emerging new methods of genetics led to further discoveries. A unique property of all living matter was revealed. We are talking about the ability to repair damaged areas in the DNA chain. They can arise as a result of various negative influences. The ability to self-repair has been called "the process of genetic repair". At present, many eminent scientists are expressing hopes, sufficiently backed by facts, that it will be possible to "snatch" certain genes from the cell. What can it give? First of all, the ability to eliminate genetic defects. Genetic engineering is the study of such problems.
Replication Process
Molecular genetics studies the processes of transmission of hereditary information during reproduction. Preservation of the invariance of the record encoded in the genes is ensured by its exact reproduction during cell division. The whole mechanism of this process has been studied in detail. It turned out that immediately before cell division occurs, replication takes place. This is the process of DNA duplication. It is accompanied by an absolutely exact copying of the original molecules according to the rule of complementarity. It is known that there are only four types of nucleotides in the DNA strand. These are guanine, adenine, cytosine and thymine. According to the rule of complementarity, discovered by scientists F. Crick and D. Watson in 1953, in the structure of the double strand of DNA, thymine corresponds to adenine, and guanyl corresponds to the cytidyl nucleotide. During the replication process, each strand of DNA is copied exactly by substitution of the desired nucleotide.
Genetics is a relatively young science. The process of replication was only studied in the 1950s. At the same time, the enzyme DNA polymerase was discovered. In the 1970s, after many years of research, it was found that replication is a multi-stage process. Several different types of DNA polymerases are directly involved in the synthesis of DNA molecules.
Genetics and health
All information related to the point reproduction of hereditary information during processes is widely used in modern medical practice. Thoroughly studied patterns are characteristic of both healthy organisms and in cases of pathological changes in them. For example, it has been proven and confirmed by experiments that the cure of some diseases can be achieved with external influence on the processes of replication of genetic material and division, especially if the pathology of the body's functioning is associated with metabolic processes. For example, diseases such as rickets and impaired phosphorus metabolism are directly caused by inhibition of DNA replication. How can you change this state from the outside? Already synthesized and tested drugs that stimulate the oppressed processes. They activate DNA replication. This contributes to the normalization and restoration of pathological conditions associated with the disease. But genetic research does not stand still. Every year more and more data is received that helps not only to cure, but to prevent a possible disease.
Genetics and drugs
Molecular genetics deals with a lot of health issues. The biology of some viruses and microorganisms is such that their activity in the human body sometimes leads to a failure of DNA replication. It has also already been established that the cause of some diseases is not the inhibition of this process, but its excessive activity. First of all, these are viral and bacterial infections. They are due to the fact that pathogenic microbes begin to multiply rapidly in the affected cells and tissues. This pathology also includes oncological diseases.
Currently, there are a number of drugs that can suppress DNA replication in the cell. Most of them were synthesized by Soviet scientists. These drugs are widely used in medical practice. These include, for example, a group of anti-tuberculosis drugs. There are also antibiotics that inhibit the processes of replication and division of pathological and microbial cells. They help the body quickly cope with foreign agents, preventing them from multiplying. These drugs provide excellent treatment for most serious acute infections. And these funds are especially widely used in the treatment of tumors and neoplasms. This is a priority direction chosen by the Institute of Genetics of Russia. Every year there are new improved drugs that prevent the development of oncology. This gives hope to tens of thousands of sick people around the world.
Transcription and translation processes
After experimental laboratory tests on genetics were carried out and results were obtained on the role of DNA and genes as templates for protein synthesis, for some time scientists expressed the opinion that amino acids are assembled into more complex molecules right there, in the nucleus. But after receiving new data, it became clear that this was not the case. Amino acids are not built on sections of genes in DNA. It was found that this complex process proceeds in several stages. First, exact copies are made from the genes - messenger RNA. These molecules leave the cell nucleus and move to special structures - ribosomes. It is on these organelles that the assembly of amino acids and protein synthesis take place. The process of making copies of DNA is called transcription. And the synthesis of proteins under the control of messenger RNA is “translation”. The study of the exact mechanisms of these processes and the principles of influence on them are the main modern tasks in the genetics of molecular structures.
Significance of transcription and translation mechanisms in medicine
In recent years, it has become apparent that scrupulous consideration of all stages of transcription and translation is of great importance for modern health care. The Institute of Genetics of the Russian Academy of Sciences has long confirmed the fact that with the development of almost any disease, there is an intensive synthesis of toxic and simply harmful proteins for the human body. This process can proceed under the control of genes that are normally inactive. Or it is an introduced synthesis, for which pathogenic bacteria and viruses that have penetrated into human cells and tissues are responsible. Also, the formation of harmful proteins can stimulate actively developing oncological neoplasms. That is why a thorough study of all stages of transcription and translation is currently extremely important. So you can identify ways to deal not only with dangerous infections, but also with cancer.
Modern genetics is a continuous search for the mechanisms of the development of diseases and drugs for their treatment. Now it is already possible to inhibit the processes of translation in the affected organs or the body as a whole, thereby suppressing inflammation. In principle, it is on this that the action of most known antibiotics, for example, tetracycline or streptomycin, is built. All of these drugs selectively inhibit translation processes in cells.
Significance of the study of genetic recombination processes
Of great importance for medicine is also a detailed study of the processes of genetic recombination, which is responsible for the transfer and exchange of sections of chromosomes and individual genes. This is an important factor in the development of infectious diseases. Genetic recombination underlies the penetration into human cells and the introduction of foreign, more often viral, material into DNA. As a result, there is a synthesis on the ribosomes of proteins that are not “native” to the body, but pathogenic for it. According to this principle, the reproduction of whole colonies of viruses occurs in the cells. The methods are aimed at developing means to combat infectious diseases and to prevent the assembly of pathogenic viruses. In addition, the accumulation of information on genetic recombination made it possible to understand the principle of gene exchange between organisms, which led to the emergence of genetically modified plants and animals.
Importance of molecular genetics for biology and medicine
Over the past century, discoveries, first in classical and then in molecular genetics, have had an enormous, and even decisive, impact on the progress of all biological sciences. Medicine has advanced a lot. Advances in genetic research have made it possible to understand the once incomprehensible processes of inheritance of genetic traits and the development of individual characteristics of a person. It is also noteworthy how quickly this science grew from a purely theoretical into a practical one. It has become essential to modern medicine. A detailed study of molecular genetic regularities served as a basis for understanding the processes occurring in the body of both a sick and a healthy person. It was genetics that gave impetus to the development of such sciences as virology, microbiology, endocrinology, pharmacology and immunology.
from the Greek genesis - origin) - the doctrine of development; genetic - related to the emergence and development, considered from the point of view of development, evolutionary-historical (eg, genetic psychology).
Great Definition
Incomplete definition ↓
GENETICS
usually defined as a science that studies the patterns of heredity and variability of living organisms. The formal birth year of genetics is considered to be 1900, although its foundations were actually formulated as early as the 19th century. Austrian monk and scientist G. Mendel (1822-1884). It was Mendel, on the basis of his classical experiments on plant hybrids, already in his work in 1865, who formulated the main ideas of all classical genetics of the 20th century: the materiality and discreteness of heredity (the existence of special units, factors of heredity) and the random-combinatorial mechanism of their transmission through the generations of living organisms. Due to the central role of genetic structures in the implementation of almost all the most important processes of life, genetics in the XX century. occupied a special - pivotal - place in the entire system of biological knowledge about wildlife, including man as part of it. Starting in 1900 with the rediscovery of Mendel's laws, genetics in the 20th century. passed a rapid path of development from the formal identification of genes (as Mendelevsky's "factors" of heredity were called at the beginning of the century) with certain sections of nuclear chromosomes to the elucidation of their true chemical nature (1944) in the form of a special class of chemical biopolymers - deoxyribonucleic acids (DNA); from the disclosure of the structure of DNA in the form of the now famous and well-known double helix (1953) to the decoding of the code of hereditary information (1961); and from the discovery of methods for fast reading, determination (or, as scientists say, sequencing) of long DNA nucleotide sequences (1977) to decoding (more precisely, sequencing) of the human genome (2000).
