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What problems does genetics solve? Gene therapy: successes, difficulties, prospects

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FEDERAL STATE EDUCATIONAL INSTITUTION

HIGHER PROFESSIONAL EDUCATION

Faculty of Economics

Department of Philosophy

INDIVIDUAL CONTROL TASK

IN THE DISCIPLINE “CONCEPT OF MODERN NATURAL SCIENCE”

1. The main problems of genetics and the role of reproduction in the development of living things

2. The role of the cell in the development of living things

3. What discovery in natural science occurred in 1955 and what is its essence?

Literature

Question 1. The main problems of genetics and the role inproduction in the development of living things

Genetics (from the Greek genesis - origin), the science of heredity and variability of living organisms and methods of managing them. For thousands of years, humans have used genetic techniques to improve domesticated animals and crops without understanding the mechanisms underlying these techniques. By selecting certain organisms from natural populations and crossing them with each other, man created improved plant varieties and animal breeds that had the properties he needed.

However, only at the beginning of the 20th century. scientists began to fully realize the importance of the laws of heredity and its mechanisms. Although advances in microscopy made it possible to establish that hereditary characteristics are transmitted from generation to generation through sperm and eggs, it remained unclear how the smallest particles of protoplasm could carry the “makings” of that huge variety of characters that make up each individual organism.

The first truly scientific step forward in the study of heredity was made by the Austrian monk Gregor Mendel, who in 1866 published a paper that laid the foundations of modern genetics.

The term “Genetics” was proposed in 1906 by W. Bateson.

Since then, genetics has made great strides in explaining the nature of heredity both at the level of the organism and at the level of the gene. The role of genes in the development of an organism is enormous. Genes characterize all the characteristics of the future organism, such as eye and skin color, size, weight and much more. Genes are carriers of hereditary information on the basis of which an organism develops.

Depending on the object of study, plant genetics, animal genetics, microbial genetics, human genetics, etc. are distinguished, and depending on the methods used in other disciplines - biochemical genetics, molecular genetics, environmental genetics, etc.

Ideas and methods of genetics find application in all areas of human activity related to living organisms. They are of great importance for solving problems in medicine, agriculture, and the microbiological industry. Interest in human genetics is due to several reasons. Firstly, this is a person’s natural desire to know himself. Secondly, after many infectious diseases were defeated - plague, cholera, smallpox, etc. - the relative proportion of hereditary diseases increased. Thirdly, once the nature of mutations and their significance in heredity were understood, it became clear that mutations can be caused by environmental factors that had not previously been given due attention. An intensive study of the effects of radiation and chemicals on heredity began. Every year, more and more chemical compounds are used in everyday life, agriculture, food, cosmetics, pharmacological industries and other areas of activity, among which many mutagens are used.

In this regard, the following main problems of genetics can be identified:

1. Nhereditary diseases and their causes - may be caused by abnormalities in individual genes, chromosomes or sets of chromosomes. For the first time, a connection between an abnormal number of chromosomes and sharp deviations from normal development was discovered in the case of Down syndrome. In addition to chromosomal disorders, hereditary diseases can be caused by changes in genetic information directly in genes.

2. Medical genetic laboratories. Knowledge of human genetics allows us to determine the likelihood of having children suffering from hereditary diseases in cases where one or both spouses are sick or both parents are healthy, but hereditary diseases occurred in their ancestors. In some cases, it is possible to predict the birth of a healthy second child if the first one was sick.

3. Are abilities inherited? Scientists believe that every person has a grain of talent. Talent is developed through hard work. Genetically, a person is richer in his capabilities, but does not fully realize them in his life. There are still no methods for identifying a person’s true abilities in the process of his childhood and youth education, and therefore the appropriate conditions for their development are often not provided.

4. Does natural selection operate in human society? Human history is a change in the genetic structure of populations of a species Homo sapiens under the influence of biological and social factors. Wars and epidemics changed the gene pool of humanity. Natural selection has not weakened over the past 2 thousand years, but only changed: social selection has been layered on top of it.

5. Genetic Engineering uses the most important discoveries of molecular genetics to develop new research methods, obtain new genetic data, as well as in practical activities, in particular in medicine.

6. Gender correction. Gender correction operations in our country began to be performed about 30 years ago strictly for medical reasons.

7. Organ transplant from donors is a very complex operation, followed by an equally difficult period of graft engraftment. Very often the graft is rejected and the patient dies. Scientists hope that these problems can be solved through cloning.

8. Cloning - a method of genetic engineering in which descendants are obtained from the somatic cell of an ancestor and therefore have exactly the same genome. Cloning animals allows us to solve many problems in medicine and molecular biology, but at the same time it gives rise to many social problems.

9. Deformities. The development of a new living being occurs in accordance with the genetic code recorded in DNA, which is contained in the nucleus of every cell in the body. Sometimes, under the influence of environmental factors - radioactive, ultraviolet rays, chemicals - the genetic code is disrupted, mutations and deviations from the norm occur.

10. Genetics and criminology. In judicial practice, there are cases of establishing kinship when children were confused in the maternity hospital. Sometimes this concerned children who grew up in other people's families for more than one year. To establish kinship, biological examination methods are used, which is carried out when the child turns 1 year old and the blood system has stabilized. A new method has been developed - gene fingerprinting, which allows analysis at the chromosomal level. In this case, the age of the child does not matter, and the relationship is established with a 100% guarantee.

All stages in the life of any living creature are important, including for humans. They all boil down to the cyclical reproduction of the original living organism. And this process of cyclical reproduction began about 4 billion years ago.

Let's consider its features. It is known from biochemistry that many reactions of organic molecules are reversible. For example, protein molecules are synthesized from amino acids, which can be broken down into amino acids. That is, under the influence of any influences, both synthesis reactions and splitting reactions occur. In living nature, any organism goes through cyclic stages of splitting the original organism and reproducing from the separated part a new copy of the original organism, which then again produces an embryo for reproduction. It is for this reason that interactions in living nature last continuously for billions of years. The property of reproducing a copy from the split parts of the original organism is determined by the fact that a complex of molecules is transferred to the new organism, which completely controls the process of recreating the copy. The process began with the self-reproduction of molecular complexes. And this path is quite well recorded in every living cell. Scientists have long noticed that in the process of embryogenesis the stages of the evolution of life are repeated. But then you should also pay attention to the fact that in the very depths of the cell, in its nucleus, there are DNA molecules. This is the best evidence that life on Earth began with the reproduction of complexes of molecules that had the property of first splitting the double helix of DNA, and then provided the process of recreating the double helix. This is the process of cyclical recreation of a living object with the help of molecules that were transferred at the moment of splitting and which completely controlled the synthesis of a copy of the original object. Therefore, the definition of life will look like this.

Life is a type of interaction of matter, the main difference of which from known types of interactions is the storage, accumulation and copying of objects, which bring certainty to these interactions and transform them from random to regular, while cyclic reproduction of a living object occurs.

Any living organism has a genetic set of molecules that completely determines the process of recreating a copy of the original object, that is, in the presence of the necessary nutrients, with a probability of one, as a result of the interaction of a complex of molecules, a copy of the living organism will be recreated. But the receipt of nutrients is not guaranteed; harmful external influences and disruption of interactions within the cell also occur. Therefore, the total probability of recreating a copy is always slightly less than one.

So, of two organisms or living objects, the organism that has the greater total probability of carrying out all the necessary interactions will be copied more efficiently. This is the law of evolution of living nature. In other words, it can be formulated this way: the more interactions necessary for copying an object are controlled by the object itself, the greater the likelihood of its cyclic reproduction.

It is obvious that if the total probability of all interactions increases, then this object evolves; if it decreases, then it involutions; if it does not change, then the object is in a stable state.

The most important function of life is the function of self-production. In other words, life activity is the process of satisfying the need for a person to reproduce his living being within the framework of the system in which he is included as an element, i.e. under environmental conditions. Taking as the initial thesis the premise that life activity has the most important need for the reproduction of its subject, as the owner of the human body, it should be noted that reproduction is carried out in two ways: firstly, in the process of consuming matter and energy from the environment, and, secondly , in the process of biological reproduction, that is, the birth of offspring. The first type of realization of the need in the “external environment-organism” link can be expressed as the reproduction of “living things from non-living things”. Man exists on earth thanks to the constant consumption of necessary substances and energy from the environment.

After the emergence and spread of life on Earth, its emergence today on the basis of inorganic matter alone is no longer possible. All living systems existing on Earth now arise either on the basis of living things, or through the mediation of living things. Thus, before a living organism reproduces itself materially and energetically, it must be reproduced biologically, that is, be born by another living organism. The reproduction of living things by living things is, first of all, the transfer from one generation to another of genetic material, which determines the appearance of a certain morphophysiological structure in the offspring. It is clear that genetic material is not transmitted from generation to generation by itself; its transmission is also a function of human life.

Question 2. The role of the cell in the development of living things

The name “cell” was first used in the mid-17th century. applied by R. Hooke. Examining a thin section of a cork using a microscope, Hooke saw that the cork consisted of cells - cells.

The cell of any organism is an integral living system. It consists of three inextricably linked parts: the membrane, the cytoplasm and the nucleus. The cell membrane directly interacts with the external environment and interacts with neighboring cells (in multicellular organisms).

The cell membrane has a complex structure. It consists of an outer layer and a plasma membrane located underneath it. Animal and plant cells differ in the structure of their outer layer. In plants, as well as in bacteria, blue-green algae and fungi, a dense membrane, or cell wall, is located on the surface of the cells. In most plants it consists of fiber. The cell wall plays an extremely important role: it is an outer frame, a protective shell, and provides turgor for plant cells: water, salts, and molecules of many organic substances pass through the cell wall.

Separated from the external environment by the plasma membrane, the cytoplasm is the internal semi-liquid environment of cells. The cytoplasm of eukaryotic cells contains the nucleus and various organelles. The nucleus is located in the central part of the cytoplasm. It also contains various inclusions - products of cellular activity, vacuoles, as well as tiny tubes and filaments that form the skeleton of the cell. Proteins predominate in the composition of the main substance of the cytoplasm. The main metabolic processes take place in the cytoplasm; it unites the nucleus and all organelles into one whole, ensures their interaction, and the activity of the cell as a single integral living system.

The entire internal zone of the cytoplasm is filled with numerous small channels and cavities, the walls of which are membranes similar in structure to the plasma membrane. These channels branch, connect with each other and form a network called the endoplasmic reticulum. The main function of the granular endoplasmic reticulum is participation in protein synthesis, which occurs in ribosomes.

Each cell of unicellular and multicellular animals, as well as plants, contains a nucleus. The shape and size of the nucleus depend on the shape and size of the cells. Most cells have one nucleus, and such cells are called mononuclear. There are also cells with two, three, several dozen and even hundreds of nuclei. These are multinucleated cells.

Nuclear juice is a semi-liquid substance that is located under the nuclear envelope and represents the internal environment of the nucleus.

In the middle of the 19th century, based on the already extensive knowledge about the cell, T. Schwann formulated the cell theory (1838). He summarized the existing knowledge about the cell and showed that the cell represents the basic structural unit of all living organisms, that the cells of animals and plants are similar in structure. These provisions were the most important evidence of the unity of origin of all living organisms, the unity of the entire organic world. T. Schwan introduced into science a correct understanding of the cell as an independent unit of life, the smallest unit of life: outside the cell there is no life.

The study of the chemical organization of a cell led to the conclusion that it is chemical processes that underlie its life, that the cells of all organisms are similar in chemical composition, and their basic metabolic processes proceed in the same way. Data on the similarity of the chemical composition of cells once again confirmed the unity of the entire organic world.

Modern cell theory includes the following provisions:

The cell is the basic unit of structure and development of all living organisms, the smallest unit of a living thing;

The cells of all unicellular and multicellular organisms are similar (homologous) in their structure, chemical composition, basic manifestations of life activity and metabolism;

Cell reproduction occurs through cell division, and each new cell is formed as a result of the division of the original (mother) cell;

In complex multicellular organisms, cells are specialized in the function they perform and form tissues;

Organs are made up of tissues, which are closely interconnected and subordinate to nervous and humoral regulatory systems.

The study of the structure, chemical composition, metabolism and all manifestations of cell activity is necessary not only in biology, but also in medicine and veterinary medicine.

Question 3.What event in natural science occurred in 1955 and what was its essence?

In 1955, Severo Ochoa isolated the bacterial enzyme polynucleotide phosphorylase, with which he obtained synthetic ribonucleic acids (RNA) with different compositions of nitrogenous bases. This achievement became the key to deciphering the genetic code.

By the twenties of the last century, it was established that the transmission of hereditary characteristics is controlled by chromosomes consisting of nucleic acids and protein. Later, chemists discovered that nucleic acids and proteins are high-molecular compounds, long-chain polymers.

In 1944 it became known that heredity finds its material or physical expression in the molecular structures of nucleic acids. Hereditary information encoded in chromosomes determines the arrangement of atoms in deoxyribonucleic acid (DNA) molecules. This was established by the American bacteriologist O. Avery, who showed experimentally that hereditary characteristics can be transmitted from one bacterial cell to another using a purified DNA preparation. Since DNA was found in the chromosomes of all cells, Avery's experiments indicated that all genes were made of DNA. Thus, elucidating the chemical structure of these molecules could be an important step toward understanding how genes are reproduced.

It should be noted that the method of DNA formation in cells was at that time one of the central problems of biology and genetics, and scientists from many countries around the world were simultaneously studying it. The discovery of the structure of DNA in 1953 revolutionized biochemistry and led to a huge amount of new research in other areas of science.
With the help of the three-dimensional model created by Watson and Crick, scientists were finally able to study DNA biosynthesis. They discovered that the DNA molecule is folded into a double helix, like a spiral staircase. Outside this helix are two layers of deoxyribose (a five-atom carbohydrate) connected by phosphate bridges. These two layers inside the helix are connected by pairs of nitrogenous bases (“rungs of the ladder”) connected to each other by hydrogen bonds. It turned out that the two halves of the DNA molecule first separate from each other, like a zipper. Next, next to each such half, its mirror image is synthesized. The sequence of nitrogenous bases, or nucleotides (one of the components into which DNA is broken down by nucleases), serves as a template for the synthesis of new molecules.

Thus, it was shown that genes located in the chromosomes of the nucleus of each cell determine the inheritance of physical characteristics and control the synthesis of proteins (enzymes). Clarification of the functions of DNA as the custodian of hereditary information has raised the question of the genetic code.

Protein synthesis occurs when genetic information is transferred to ribonucleic acid, which is similar in structure to DNA. In principle, RNA can form double helices and perform hereditary functions like DNA. But in most organisms, RNA performs its main functions in the form of single-stranded molecules. Three types of RNA are involved in the sequential incorporation of amino acids into a protein molecule: messenger, ribosomal and transport. Thanks to the same properties of complementarity (mutual correspondence in the chemical structure of two macromolecules) of bases, RNA makes copies, or “working templates,” from DNA molecules stored in the cell nucleus.

Thus, by 1957, it was established that the genetic instructions for protein synthesis are encoded in the sequence of nitrogenous bases in DNA and RNA. A few years later, Watson wrote about this situation in biochemistry: “Even after the role of RNA in protein synthesis was largely understood, scientists were not particularly optimistic about the prospects for deciphering the genetic code. It was assumed that the identification of codons (for each individual amino acid) would require an accurate determination of both the sequence of bases in the gene and the sequence of amino acids in the protein product of the gene." The “master key” with which the rapid “breaking” of the code began turned out to be polymers synthesized using the enzyme polynucleotide phosphorylase, discovered in 1955 by Ochoa and co-workers.

Ochoa's work was the first to really show the universality of the genetic code. They became the basis for the development of methods and directions for replication (repetition) of the genetic material of a cell.

In 1959, the scientist was awarded the Nobel Prize in Physiology or Medicine.

Literature

1. Chemical bases of heredity. Per. from English Ed. I.L. Knunyantsa, B.N. Sidorova. M.: Foreign. lit., 1963

2. Ruzavin G.I. The concept of modern natural science: A textbook for universities. - M.: UNITY, 2000.

3. Gaisinovich A.K. The origin and development of genetics. -- M., 1988

4. Gershenzon S.M. Fundamentals of modern genetics. -- Kyiv, 1993

5. Kibernstern F. Genes and genetics. - M.: Publishing house Paragraph, 1995.

1.5. The main stages of the development of genetics…………………………..11

1.6 Genetics and humans…………………………………………….18

Chapter 2. The role of reproduction in the development of living things……………. 23

2.1. Features of cyclic reproduction……………23

Conclusion………………………………………………………...27

Bibliographic list of used literature…………….…29

Introduction

For my work on the subject “Concepts of modern natural science,” I chose the topic “Main problems of genetics and the role of reproduction in the development of living things,” because genetics is one of the main, most fascinating and at the same time complex disciplines of modern natural science.

Genetics, which turned the biology of the 20th century into an exact scientific discipline, continuously amazes the imagination of “broad layers” of the scientific and pseudo-scientific community with new directions and more and more new discoveries and achievements. For thousands of years, people have used genetic methods to improve the beneficial properties of cultivated plants and breed highly productive breeds of domestic animals, without having any understanding of the mechanisms underlying these methods.

Only at the beginning of the  century did scientists begin to fully realize the importance of the laws of heredity and its mechanisms. Although the success of microscopy made it possible to establish that hereditary characteristics are transmitted from generation to generation through sperm and eggs, it remained unclear how the smallest particles of protoplasm could carry the “makings” of that huge variety of characteristics that make up each individual organism.

Chapter 1. Subject of genetics

1.1 What genetics studies.

Genetics is the science of heredity and variability of organisms. Genetics is a discipline that studies the mechanisms and patterns of heredity and variability of organisms, methods of controlling these processes. It is intended to reveal the laws of reproduction of living things through generations, the emergence of new properties in organisms, the laws of individual development of an individual and the material basis of historical transformations of organisms in the process of evolution.

Depending on the object of study, plant genetics, animal genetics, microbial genetics, human genetics, etc. are distinguished, and depending on the methods used in other disciplines, biochemical genetics, molecular genetics, environmental genetics, etc.

Genetics makes a huge contribution to the development of the theory of evolution (evolutionary genetics, population genetics). Ideas and methods of genetics find application in all areas of human activity related to living organisms. They are important for solving problems in medicine, agriculture, and the microbiological industry. The latest advances in genetics are associated with the development of genetic engineering.

In modern society, genetic issues are widely discussed in different audiences and from different points of view, including ethical ones, obviously for two reasons.

The need to understand the ethical aspects of using new technologies has always arisen.

The difference between the modern period is that the speed of implementation of an idea or scientific development has increased sharply as a result.

1.2. Modern ideas about the gene.

The role of genes in the development of an organism is enormous. Genes characterize all the characteristics of the future organism, such as eye and skin color, size, weight and much more. Genes are carriers of hereditary information on the basis of which an organism develops.

Just as in physics the elementary units of matter are atoms, in genetics the elementary discrete units of heredity and variability are genes. The chromosome of any organism, be it a bacterium or a human, contains a long (from hundreds of thousands to billions of nucleotide pairs) continuous strand of DNA, along which many genes are located. Establishing the number of genes, their exact location on the chromosome and their detailed internal structure, including knowledge of the complete nucleotide sequence, is a task of exceptional complexity and importance. Scientists successfully solve it using a whole range of molecular, genetic, cytological, immunogenetic and other methods.

1.2. Gene structure.

Coding chain

Regulatory zone

Promoter

Exon 1

Promoter

Intron 1

Exon 2

Promoter

Exon 3

Intron2

Terminator

mRNA

Transcription

Splicing

Mature mRNA

According to modern concepts, the gene encoding the synthesis of a certain protein in eukaryotes consists of several essential elements. (Fig) First of all, this is an extensive regulatory a zone that has a strong influence on the activity of a gene in a particular tissue of the body at a certain stage of its individual development. Next is the promoter, directly adjacent to the coding elements of the gene -

a DNA sequence up to 80-100 nucleotide pairs long, responsible for binding the RNA polymerase that transcribes a given gene. Following the promoter lies the structural part of the gene, which contains information about the primary structure of the corresponding protein. For most eukaryotic genes, this region is significantly shorter than the regulatory zone, but its length can be measured in thousands of nucleotide pairs.

An important feature of eukaryotic genes is their discontinuity. This means that the protein-coding region of the gene consists of two types of nucleotide sequences. Some are exons - sections of DNA that carry information about the structure of a protein and are part of the corresponding RNA and protein. Others, introns, do not encode protein structure and are not included in the mature mRNA molecule, although they are transcribed. The process of cutting out introns - “unnecessary” sections of the RNA molecule and splicing exons during the formation of mRNA is carried out by special enzymes and is called splicing(stitching, splicing). Exons are usually joined together in the same order as they appear in the DNA. However, not absolutely all eukaryotic genes are discontinuous. In other words, some genes, like bacterial ones, have a complete correspondence of the nucleotide sequence to the primary structure of the proteins they encode.

1.3. Basic concepts and methods of genetics.

Let us introduce the basic concepts of genetics. When studying patterns of inheritance, individuals are usually crossed that differ from each other in alternative (mutually exclusive) characters (for example, yellow and green color, smooth and wrinkled surface of peas). Genes that determine the development of alternative traits are called allelic. They are located in identical loci (locations) of homologous (paired) chromosomes. An alternative trait and the corresponding gene, manifested in first-generation hybrids, are called dominant, and those not manifested (suppressed) are called recessive. If both homologous chromosomes contain the same allelic genes (two dominant or two recessive), then such an organism is called homozygous. If different genes of the same allelic pair are localized on homologous chromosomes, then such an organism is usually called heterozygous on this basis. It forms two types of gametes and, when crossed with an organism of the same genotype, produces splitting.

The set of all genes in an organism is called genotype. A genotype is a collection of genes that interact with each other and influence each other. Each gene is influenced by other genes of the genotype and itself influences them, so the same gene can manifest itself differently in different genotypes.

The totality of all the properties and characteristics of an organism is called phenotype. The phenotype develops on the basis of a specific genotype as a result of interaction with environmental conditions. Organisms that have the same genotype may differ from each other depending on conditions.

Representatives of any biological species reproduce creatures similar to themselves. This property of descendants to be similar to their ancestors is called heredity.

Features of the transmission of hereditary information are determined by intracellular processes: mitosis and meiosis. Mitosis is the process of distributing chromosomes to daughter cells during cell division. As a result of mitosis, each chromosome of the parent cell is duplicated and identical copies disperse to the daughter cells; in this case, hereditary information is completely transmitted from one cell to two daughter cells. This is how cell division occurs in ontogenesis, i.e. process of individual development. Meiosis is a specific form of cell division that occurs only during the formation of sex cells, or gametes (sperm and eggs). Unlike mitosis, the number of chromosomes during meiosis is halved; each daughter cell receives only one of the two homologous chromosomes of each pair, so that in half of the daughter cells there is one homologue, in the other half there is another; in this case, chromosomes are distributed in gametes independently of each other. (The genes of mitochondria and chloroplasts do not follow the law of equal distribution during division.) When two haploid gametes merge (fertilization), the number of chromosomes is restored again - a diploid zygote is formed, which received a single set of chromosomes from each parent.

Despite the enormous influence of heredity in the formation of the phenotype of a living organism, related individuals differ to a greater or lesser extent from their parents. This property of descendants is called variability. The science of genetics studies the phenomena of heredity and variability. Thus, genetics is the science of the patterns of heredity and variability. According to modern concepts, heredity is the property of living organisms to transmit from generation to generation features of morphology, physiology, biochemistry and individual development under certain environmental conditions. Variability- a property opposite to heredity is the ability of daughter organisms to differ from their parents in morphological, physiological, biological characteristics and deviations in individual development.

The study of phenotypic differences in any large population shows that there are two forms of variation - discrete and continuous. To study variation in a trait, such as height in humans, it is necessary to measure that trait across a large number of individuals in the population being studied.

Heredity and variability are realized in the process of inheritance, i.e. when transmitting genetic information from parents to offspring through germ cells (in sexual reproduction) or through somatic cells (in asexual reproduction) Today, genetics is a single comprehensive science that uses both biological and physicochemical methods to solve a wide range of major biological problems.

1.4. Problems and methods of genetics research.

The global fundamental issues of modern genetics include the following problems:

1. Variability of the hereditary apparatus of organisms (mutagenesis, recombinogenesis and directed variability), which plays a vital role in selection, medicine and the theory of evolution.

2. Environmental problems associated with the genetic consequences of chemical and radiation pollution of the environment surrounding people and other organisms.

3. Growth and reproduction of cells and their regulation, formation of a differentiated organism from one cell and control of development processes; cancer problem.

4. The problem of protecting the body, immunity, tissue compatibility during tissue and organ transplantation.

5. The problem of aging and longevity.

6. The emergence of new viruses and the fight against them.

7. Particular genetics of different species of plants, animals and microorganisms, allowing to identify and isolate new genes for use in biotechnology and breeding.

8. The problem of productivity and quality of agricultural plants and animals, their resistance to adverse environmental conditions, infections and pests.

To solve these problems, different research methods are used.

Method hybridological analysis was developed by Gregor Mendel. This method allows us to identify patterns of inheritance of individual characteristics during sexual reproduction of organisms. Its essence is as follows: the analysis of inheritance is carried out according to individual independent characteristics; the transmission of these characteristics over a number of generations can be traced; An accurate quantitative account is taken of the inheritance of each alternative trait and the nature of the offspring of each hybrid separately.

Cytogenetic method allows you to study the karyotype (set of chromosomes) of body cells and identify genomic and chromosomal mutations.

Genealogical method involves the study of the pedigrees of animals and humans and allows us to establish the type of inheritance (for example, dominant, recessive) of a particular trait, the zygosity of organisms and the likelihood of the manifestation of traits in future generations. This method is widely used in breeding and medical genetic consultations.

Twin method is based on the study of the manifestation of traits in identical and fraternal twins. It allows us to identify the role of heredity and the external environment in the formation of specific characteristics.

Biochemical methods Research is based on the study of enzyme activity and the chemical composition of cells, which are determined by heredity. Using these methods, it is possible to identify gene mutations and heterozygous carriers of recessive genes.

Population statistical method allows you to calculate the frequency of occurrence of genes and genotypes in populations.

development and existence. A separate feature is called hairdryer. Phenotypic characteristics include not only external characteristics (eye color, hair, nose shape, flower color, etc.), but also anatomical (stomach volume, liver structure, etc.), biochemical (glucose and urea concentration in blood serum, etc. ) and others.

1.5. The main stages of development of genetics.

The origins of genetics, like any science, should be sought in practice. Genetics arose in connection with the breeding of domestic animals and the cultivation of plants, as well as with the development of medicine. Since man began to use the crossing of animals and plants, he was faced with the fact that the properties and characteristics of the offspring depend on the properties of the parent individuals chosen for crossing.

The development of the science of heredity and variability was especially strongly promoted by Charles Darwin's doctrine of the origin of species, which introduced into biology the historical method of studying the evolution of organisms. Darwin himself put a lot of effort into studying heredity and variation. He collected a huge amount of facts and made a number of correct conclusions based on them, but he was unable to establish the laws of heredity. His contemporaries, the so-called hybridizers, who crossed various forms and looked for the degree of similarity and difference between parents and descendants, were also unable to establish general patterns of inheritance.

First The real scientific step forward in the study of heredity was made by the Austrian monk Gregor Mendel (1822-1884), who in 1866 published an article that laid the foundations of modern genetics. Mendel showed that hereditary inclinations do not mix, but are transmitted from parents to descendants in the form of discrete (separate) units. These units, present in pairs in individuals, remain discrete and are transmitted to subsequent generations in male and female gametes, each of which contains one unit from each pair.

Brief summary of the essence of Mendel's hypotheses

1. Each trait of a given organism is controlled by a pair of alleles.

2. If an organism contains two different alleles for a given trait, then one of them (dominant) can manifest itself, completely suppressing the manifestation of the other trait (recessive).

3. During meiosis, each pair of alleles is separated (split) and each gamete receives one of each pair of alleles (cleavage principle).

4. During the formation of male and female gametes, any allele from one pair can enter each of them along with any other from another pair (the principle of independent distribution).

5.Each allele is passed on from generation to generation as a discrete, unchanging unit.

6.Each organism inherits one allele (for each trait) from each parent.

For the theory of evolution, these principles were of cardinal importance. They revealed one of the most important sources of variability, namely the mechanism for maintaining the fitness of the characteristics of a species over a number of generations. If the adaptive characteristics of organisms that arose under the control of selection were absorbed and disappeared during crossing, then the progress of the species would be impossible.

All subsequent development of genetics was associated with the study and expansion of these principles and their application to the theory of evolution and selection.

On the second stage August Weissmann (1834-1914) showed that germ cells are isolated from the rest of the body and therefore are not subject to influences acting on somatic tissues.

Despite Weismann's convincing experiments, which were easy to verify, Lysenko's supporters, who were victorious in Soviet biology, denied genetics for a long time, calling it Weismannism-Morganism. In this case, ideology defeated science, and many scientists, such as N.I. Vavilov, were repressed.

On the third stage Hugo de Vries (1848-1935) discovered the existence of heritable mutations that form the basis of discrete variability. He suggested that new species arose due to mutations.

Mutations are partial changes in the structure of a gene. Its final effect is a change in the properties of proteins encoded by mutant genes. The trait that appears as a result of mutation does not disappear, but accumulates. Mutations are caused by radiation, chemical compounds, temperature changes and can be simply random.

On the fourth stage, Thomas Maughan (1866-1945) created the chromosome theory of heredity, according to which each biological species has a strictly defined number of chromosomes.

On the fifth stage G. Meller in 1927 established that the genotype can change under the influence of X-rays. This is where induced mutations originate, and what was later called genetic engineering with its enormous possibilities and dangers of interfering with the genetic mechanism.

On the sixth stage J. Beadle and E. Tatum in 1941 identified the genetic basis of biosynthesis.

On the seventh stage, James Watson and Francis Crick proposed a model of the molecular structure of DNA and the mechanism of its replication. They found that each DNA molecule is composed of two polydeoxyribonucleic chains, spirally twisted around a common axis.

In the period from the 40s to the present time, a number of discoveries (mainly on microorganisms) of completely new genetic phenomena have been made, revealing the possibilities of analyzing gene structure at the molecular level. In recent years, with the introduction of new research methods into genetics, borrowed from microbiology, we have come to the solution to how genes control the sequence of amino acids in a protein molecule.

First of all, it should be said that it has now been fully proven that the carriers of heredity are chromosomes, which consist of a bundle of DNA molecules.

Quite simple experiments were carried out: pure DNA was isolated from killed bacteria of one strain with a special external characteristic and transferred to living bacteria of another strain, after which the reproducing bacteria of the latter acquired the characteristic of the first strain. Numerous similar experiments show that DNA is the carrier of heredity.

Currently, approaches have been found to solving the problem of organizing the hereditary code and experimentally deciphering it. Genetics, together with biochemistry and biophysics, has come close to elucidating the process of protein synthesis in a cell and the artificial synthesis of protein molecules. This begins a completely new stage in the development of not only genetics, but all biology as a whole.

The development of genetics to this day is a continuously expanding background of research into the functional, morphological and biochemical discreteness of chromosomes. A lot has already been done in this area, a lot has already been done, and every day the cutting edge of science is approaching the goal - unraveling the nature of the gene. To date, a number of phenomena have been established that characterize the nature of the gene. Firstly, a gene on a chromosome has the property of self-reproduction (autoreproduction); secondly, it is capable of mutational change; thirdly, it is associated with a certain chemical structure of deoxyribonucleic acid - DNA; fourthly, it controls the synthesis of amino acids and their sequences in protein molecules. In connection with recent research, a new idea of the gene as a functional system is being formed, and the effect of the gene on the determination of traits is considered in an integral system of genes - the genotype.

The emerging prospects for the synthesis of living matter attract great attention from geneticists, biochemists, physicists and other specialists.

Over the past decades, there has been a qualitative change in genetics as a science: a new research methodology has emerged - genetic engineering, which has revolutionized genetics and led to the rapid development of molecular genetics and genetic engineering biotechnology.

The modern development of general and specific genetics, molecular genetics and genetic engineering occurs with mutual enrichment of ideas and methods and is compiled through purely genetic analysis, i.e. obtaining mutations and carrying out certain crosses. It was possible to reveal many fundamental laws of life, i.e. Already in the early stages of its development, genetics became an exact experimental science.

Without highly developed general and molecular genetics, there can be no effective progress in virtually any area of modern biology, selection, or protection of people's hereditary health.

Genetics and genetic engineering are no less important in the development of the national economy.

Modern selection uses methods of induced mutations and recombinations, heterosis, polyploidy, immunogenetics, cell engineering, distant hybridization, protein and DNA markers and others. Their implementation in breeding centers is extremely fruitful.

Currently, industrial microbiological synthesis of a number of products necessary for medicine, agriculture and industry is carried out using genetic engineering. The synthesis of other valuable products is carried out in cell cultures.

The development of microbial genetics largely determines the efficiency of the microbiological industry.

Now a new stage in the development of genetic engineering is being outlined - the transition to the use of plants and animals with genes responsible for the synthesis of the corresponding products transplanted into them as sources of valuable products, i.e. creation and use of transgenic plants and animals. By creating transgenic organisms, the problems of obtaining new plant varieties and animal breeds with increased productivity, as well as resistance to infectious diseases and unfavorable environmental conditions will be solved.

The development of genetic engineering has created a fundamentally new basis for constructing DNA sequences needed by researchers. Advances in experimental biology have made it possible to create methods for introducing such artificially created genes into the nuclei of eggs or sperm. As a result, it became possible to obtain transgenic animals, those. animals that carry foreign genes in their bodies.

One of the first examples of the successful creation of transgenic animals was the production of mice in which the rat growth hormone was built into their genome. Some of these transgenic mice grew rapidly and reached sizes significantly larger than control animals.

The world's first monkey with a modified genetic code was born in America. The male, named Andy, was born after the jellyfish gene was inserted into his mother's egg. The experiment was carried out with the rhesus monkey, which is much closer in its biological characteristics to humans than any other animal that has so far been subjected to genetic modification experiments. Scientists say the technique will help them develop new treatments for diseases such as breast cancer and diabetes. However, as the BBC reports, the experiment has already drawn criticism from animal welfare groups who fear the research will lead to the suffering of many primates in laboratories.

Creation of a human-pig hybrid. The nucleus is removed from a human cell and implanted into the nucleus of a pig egg, which has previously been freed from the animal’s genetic material. The result was an embryo that lived for 32 days until scientists decided to destroy it. Research is carried out, as always, for a noble goal: finding cures for human diseases. Although attempts to clone human beings are frowned upon by many scientists and even those who created Dolly the sheep, such experiments will be difficult to stop since the principle of the cloning technique is already known to many laboratories.

Currently, there is great interest in transgenic animals. This is due to two reasons. Firstly, wide opportunities have arisen for studying the operation of a foreign gene in the genome of the host organism, depending on the location of its insertion into a particular chromosome, as well as the structure of the gene’s regulatory zone. Secondly, transgenic farm animals may be of practical interest in the future.

Of great importance for medicine is the development of methods for prenatal diagnosis of genetic defects and those structural features of the human genome that contribute to the development of serious diseases: cancer, cardiovascular, mental and others.

The task has been set to create national and global genetic monitoring, i.e. tracking the genetic load and gene dynamics in people's heritage. This will be of great importance for assessing the influence of environmental mutagens and monitoring demographic processes.

The development of methods for correcting genetic defects through gene transplantation (hemotherapy) began and will develop in the 90s.

Advances in the field of studying the functioning of various genes will make it possible in the 90s to approach the development of rational methods of treating tumor, cardiovascular, and a number of viral and other dangerous diseases of humans and animals.

1.6 Genetics and humans.

In human genetics, the direct connection of scientific research with ethical issues is clearly visible, as well as the dependence of scientific research on the ethical meaning of their final results. Genetics has advanced so much that man is on the threshold of such power that allows him to determine his biological destiny. That is why the use of all the potential possibilities of medical genetics is possible only with strict adherence to ethical standards.

Human genetics, rapidly developing in recent decades, has provided answers to many of the questions that have long interested people: what determines the sex of a child? Why do children look like their parents? Which signs and diseases are inherited and which are not, why are people so different from each other, why are closely related marriages harmful?

Interest in human genetics is due to several reasons. Firstly, this is a person’s natural desire to know himself. Secondly, after many infectious diseases were defeated - plague, cholera, smallpox, etc. - the relative proportion of hereditary diseases increased. Thirdly, once the nature of mutations and their significance in heredity were understood, it became clear that mutations can be caused by environmental factors that had not previously been given due attention. An intensive study of the effects of radiation and chemicals on heredity began. Every year, more and more chemical compounds are used in everyday life, agriculture, food, cosmetics, pharmacological industries and other areas of activity, among which many mutagens are used.

In this regard, the following main problems of genetics can be identified.

Hereditary diseases and their causes. Hereditary diseases can be caused by disorders in individual genes, chromosomes or chromosome sets. For the first time, a connection between an abnormal number of chromosomes and sharp deviations from normal development was discovered in the case of Down syndrome.

In addition to chromosomal disorders, hereditary diseases can be caused by changes in genetic information directly in genes.

There are no effective treatments for hereditary diseases yet. However, there are treatment methods that alleviate the condition of patients and improve their well-being. They are based mainly on compensation for metabolic defects caused by disturbances in the genome.

Medical genetic laboratories. Knowledge of human genetics allows us to determine the likelihood of having children suffering from hereditary diseases in cases where one or both spouses are sick or both parents are healthy, but hereditary diseases occurred in their ancestors. In some cases, it is possible to predict the birth of a healthy second child if the first one was sick. Such forecasting is carried out in medical genetic laboratories. The widespread use of medical genetic consultations will save many families from the misfortune of having sick children.

Are abilities inherited? Scientists believe that every person has a grain of talent. Talent is developed through hard work. Genetically, a person is richer in his capabilities, but does not fully realize them in his life.
There are still no methods for identifying a person’s true abilities in the process of his childhood and youth education, and therefore the appropriate conditions for their development are often not provided.

Does natural selection operate in human society? The history of mankind is a change in the genetic structure of populations of the species Homo sapiens under the influence of biological and social factors. Wars and epidemics changed the gene pool of humanity. Natural selection has not weakened over the past 2 thousand years, but only changed: social selection has been layered on top of it.

Genetic Engineering uses the most important discoveries of molecular genetics to develop new research methods, obtain new genetic data, as well as in practical activities, in particular in medicine.

Previously, vaccines were made only from killed or weakened bacteria or viruses that could induce immunity in humans due to the formation of specific antibody proteins. Such vaccines lead to the development of lasting immunity, but they also have disadvantages.

It is safer to vaccinate with pure proteins of the shells of viruses - they cannot multiply, because they do not have nucleic acids, but cause the production of antibodies. They can be obtained using genetic engineering methods. Such a vaccine has already been created against infectious hepatitis (Botkin's disease), a dangerous and difficult-to-treat disease. Work is underway to create pure vaccines against influenza, anthrax and other diseases.

Gender correction. Gender correction operations in our country began to be performed about 30 years ago strictly for medical reasons.

Organ transplantation. Organ transplantation from donors is a very complex operation, followed by an equally difficult period of graft engraftment. Very often the graft is rejected and the patient dies. Scientists hope that these problems can be solved through cloning.

Cloning- a method of genetic engineering in which descendants are obtained from the somatic cell of an ancestor and therefore have exactly the same genome.

Cloning animals allows us to solve many problems in medicine and molecular biology, but at the same time it gives rise to many social problems.

Scientists see the prospect of reproducing individual tissues or organs of seriously ill people for subsequent transplantation - in this case there will be no problems with transplant rejection. Cloning can also be used to obtain new drugs, especially those obtained from tissues and organs of animals or humans.

However, despite the attractive prospects, the ethical side of cloning raises concerns.

Deformities. The development of a new living being occurs in accordance with the genetic code recorded in DNA, which is contained in the nucleus of every cell in the body. Sometimes, under the influence of environmental factors - radioactive, ultraviolet rays, chemicals - the genetic code is disrupted, mutations and deviations from the norm occur.

Genetics and criminology. In judicial practice, there are cases of establishing kinship when children were confused in the maternity hospital. Sometimes this concerned children who grew up in other people's families for more than one year. To establish kinship, biological examination methods are used, which is carried out when the child turns 1 year old and the blood system has stabilized. A new method has been developed - gene fingerprinting, which allows analysis at the chromosomal level. In this case, the age of the child does not matter, and the relationship is established with a 100% guarantee.

Chapter 2. The role of reproduction in the development of living things.

2.1. Features of cyclic reproduction.

The process began with the self-reproduction of molecular complexes. And this path is quite well recorded in every living cell. Scientists have long noticed that in the process of embryogenesis the stages of the evolution of life are repeated. But then you should also pay attention to the fact that in the very depths of the cell, in its nucleus, there are DNA molecules. This is the best evidence that life on Earth began with the reproduction of complexes of molecules that had the property of first splitting the double helix of DNA, and then provided the process of recreating the double helix. This is the process of cyclical recreation of a living object with the help of molecules that were transferred at the moment of splitting and which completely controlled the synthesis of a copy of the original object. Therefore, the definition of life will look like this. Life is a type of interaction of matter, the main difference of which from known types of interactions is the storage, accumulation and copying of objects that bring certainty to these interactions and transfer them from random to regular, while cyclic reproduction of a living object occurs.

Any living organism has a genetic set of molecules that completely determines the process of recreating a copy of the original object. That is, in the presence of the necessary nutrients, with a probability of one, as a result of the interaction of a complex of molecules, a copy of a living organism will be recreated. But the receipt of nutrients is not guaranteed; harmful external influences and disruption of interactions within the cell also occur. Therefore, the total probability of recreating a copy is always slightly less than one. So, of two organisms or living objects, the organism that has the greater total probability of carrying out all the necessary interactions will be copied more efficiently. This is the law of evolution of living nature. In other words, it can be formulated this way: the more interactions necessary for copying an object are controlled by the object itself, the greater the likelihood of its cyclic reproduction.

It is obvious that if the total probability of all interactions increases, then this object evolves; if it decreases, then it involutions; if it does not change, then the object is in a stable state.

The most important function of life is the function of self-production. In other words, life activity is the process of satisfying the need for a person to reproduce his living being within the framework of the system in which he is included as an element, i.e. under environmental conditions. Taking as the initial thesis the premise that life activity has the most important need for the reproduction of its subject, as the owner of the human body, it should be noted that reproduction is carried out in two ways: firstly, in the process of consuming matter and energy from the environment, and secondly, in the process of biological reproduction, that is, the birth of offspring. The first type of realization of the need in the “external environment-organism” link can be expressed as the reproduction of “living things from non-living things”. Man exists on earth thanks to the constant consumption of necessary substances and energy from the environment.

IN AND. Vernadsky, in his famous work “Biosphere,” presented the process of life on Earth as a constant cycle of matter and energy, in which humans must be included, along with other creatures. Atoms and molecules of physical substances that make up the Earth's biosphere have been included in and out of its circulation millions of times during the existence of life. The human body is not identical to the substance and energy consumed from the external environment; it is the object of its life activity transformed in a certain way. As a result of the realization of the needs for substances, energy, and information, another object of nature arises from one object, possessing properties and functions that are not at all inherent in the original object. This reveals a special, necessarily inherent type of human activity. Such activity can be defined as a need aimed at material and energy reproduction. The content of the realization of this need is the extraction of means of life from the environment. Extraction in the broad sense includes both extraction itself and production.

This type of reproduction is not the only one necessary for the existence of life. V.I. Vernadsky wrote that a living organism, “dying, living and collapsing, gives its atoms to it and continuously takes them from it, but a living substance embraced by life always has a beginning in the living.” The second type of reproduction is also necessarily inherent in all life on Earth. Science has proven with sufficient certainty that the direct generation of living things from non-living matter is impossible at this stage of the Earth’s development.

Conclusion.

Genetics is the science of heredity and variability of organisms. Genetics is a discipline that studies the mechanisms and patterns of heredity and variability of organisms, and methods for controlling these processes. It is intended to reveal the laws of reproduction of living things through generations, the emergence of new properties in organisms, the laws of individual development of an individual and the material basis of historical transformations of organisms in the process of evolution. The objects of genetics are viruses, bacteria, fungi, plants, animals and humans. Against the background of species and other specificities, general laws are revealed in the phenomena of heredity for all living beings. Their existence shows the unity of the organic world.

In modern society, genetic issues are widely discussed in different audiences and from different points of view, including ethical ones, obviously for two reasons.

Firstly, genetics affects the most primary properties of living nature, as if key positions in life manifestations. Therefore, the progress of medicine and biology, as well as all expectations from it, often focus on genetics. In many ways, this focus is justified.

Secondly, in recent decades genetics has been developing so rapidly that it gives rise to both scientific and pseudo-scientific promising forecasts. This is especially true for human genetics, the progress of which raises ethical issues more acutely than in other areas of biomedical science.

In human genetics, the direct connection of scientific research with ethical issues is clearly visible, as well as the dependence of scientific research on the ethical meaning of their final results. Genetics has advanced so much that man is on the threshold of such power that allows him to determine his biological destiny. That is why the use of all the potential possibilities of genetics is possible only with strict adherence to ethical standards.

Genetics occupies a very important place in the system of modern sciences, and, perhaps, the most important achievements of the last decade of the past century are associated precisely with genetics. Now, at the beginning of the 21st century, prospects are opening up before humanity that captivate the imagination. Will scientists be able to realize the gigantic potential inherent in genetics in the near future? Will humanity receive the long-awaited deliverance from hereditary diseases, will man be able to prolong his too short life and gain immortality? At present we have every reason to hope for this.

Bibliographic list of used literature:

Artyomov A. What is a gene. - Taganrog: Publishing house “Red Page”, 1989.

Biological encyclopedic dictionary. - M.: Sov. encyclopedia, 1989.

Vernadsky V.I. Chemical structure of the Earth’s biosphere and its environment. - M.: Nauka, 1965.

consciousness and cognitive processes in the formation alive... which are aimed at development And reproduction relationships with certain... population ecology and genetics, mathematical genetics. "New... Therefore these three basic Problems and demand...
Genetics. Lecture notes
Abstract >> Biology
... role genetics V development medicine. Main sections of modern genetics are: cytogenetics, molecular genetics, mutagenesis, population, evolutionary and ecological genetics ...

The textbook complies with the Federal State Educational Standard of Secondary (complete) general education, is recommended by the Ministry of Education and Science of the Russian Federation and is included in the Federal List of Textbooks.

The textbook is addressed to 10th grade students and is designed to teach the subject 1 or 2 hours a week.

Modern design, multi-level questions and assignments, additional information and the ability to work in parallel with an electronic application contribute to the effective assimilation of educational material.

What is the importance of microbial selection for industry and agriculture?

Biotechnology – is the use of organisms, biological systems or biological processes in industrial production. The term "biotechnology" has become widespread since the mid-70s. XX century, although since time immemorial mankind has used microorganisms in baking and winemaking, in the production of beer and in cheese making. Any production that is based on a biological process can be considered biotechnology. Genetic, chromosomal and cellular engineering, cloning of agricultural plants and animals are various aspects of modern biotechnology.

Biotechnology not only makes it possible to obtain products important for humans, such as antibiotics and growth hormone, ethyl alcohol and kefir, but also to create organisms with predetermined properties much faster than using traditional breeding methods. There are biotechnological processes for wastewater treatment, waste processing, removal of oil spills in water bodies, and production of fuel. These technologies are based on the characteristics of the life activity of certain microorganisms.

Emerging modern biotechnologies are changing our society, opening up new opportunities, but at the same time creating certain social and ethical problems.

Genetic Engineering. Convenient objects of biotechnology are microorganisms that have a relatively simply organized genome, a short life cycle and a wide variety of physiological and biochemical properties.

One of the causes of diabetes is a lack of insulin, a pancreatic hormone, in the body. Injections of insulin isolated from the pancreas of pigs and cattle save millions of lives, but lead to allergic reactions in some patients. The optimal solution would be to use human insulin. Using genetic engineering methods, the human insulin gene was inserted into the DNA of Escherichia coli. The bacterium began to actively synthesize insulin. In 1982, human insulin became the first pharmaceutical drug produced using genetic engineering methods.

Rice. 107. Countries growing transgenic plants. Almost the entire area sown with transgenic crops is occupied by genetically modified varieties of four plants: soybeans (62%), corn (24%), cotton (9%) and rapeseed (4%). Varieties of transgenic potatoes, tomatoes, rice, tobacco, beets and other crops have already been created

Growth hormone is currently obtained in a similar way. A human gene embedded in the genome of bacteria provides the synthesis of a hormone, injections of which are used in the treatment of dwarfism and restore the growth of sick children to almost normal levels.

Just like in bacteria, using genetic engineering methods it is possible to change the hereditary material of eukaryotic organisms. Such genetically rearranged organisms are called transgenic or genetically modified organisms(GMO).

In nature, there is a bacterium that produces a toxin that kills many harmful insects. The gene responsible for the synthesis of this toxin was isolated from the bacterial genome and inserted into the genome of cultivated plants. To date, pest-resistant varieties of corn, rice, potatoes and other agricultural plants have already been created. Growing such transgenic plants that do not require the use of pesticides has enormous advantages, because, firstly, pesticides kill not only harmful but also beneficial insects, and secondly, many pesticides accumulate in the environment and have a mutagenic effect on living organisms (Fig. 107).

One of the first successful experiments on the creation of genetically modified animals was carried out on mice in whose genome the rat growth hormone gene was inserted. As a result, the transgenic mice grew much faster and ended up being twice the size of normal mice. If this experience had exclusively theoretical significance, then the experiments in Canada already had obvious practical application. Canadian scientists introduced a gene from another fish into the salmon's genetic material, which activated the growth hormone gene. This caused the salmon to grow 10 times faster and gain weight several times higher than normal.

Cloning. The creation of multiple genetic copies of one individual through asexual reproduction is called cloning. In a number of organisms, this process can occur naturally; remember vegetative propagation in plants and fragmentation in some animals (). If a piece of a ray is accidentally torn off from a starfish, a new full-fledged organism is formed from it (Fig. 108). In vertebrates this process does not occur naturally.

The first successful animal cloning experiment was carried out by researcher Gurdon in the late 60s. XX century at Oxford University. The scientist transplanted a nucleus taken from an epithelial cell of the intestine of an albino frog into an unfertilized egg of an ordinary frog, whose nucleus had previously been destroyed. From such an egg, the scientist managed to grow a tadpole, which then turned into a frog, which was an exact copy of the albino frog. Thus, for the first time it was shown that the information contained in the nucleus of any cell is sufficient for the development of a full-fledged organism.

Rice. 108. Regeneration of a starfish from one ray

Subsequent research conducted in Scotland in 1996 led to the successful cloning of Dolly the sheep from the mother's mammary gland epithelial cell (Fig. 109).

Cloning appears to be a promising method in animal husbandry. For example, when breeding cattle, the following technique is used. At an early stage of development, when the cells of the embryo are not yet specialized, the embryo is divided into several parts. From each fragment placed in an adoptive (surrogate) mother, a full-fledged calf can develop. In this way, it is possible to create many identical copies of one animal with valuable qualities.

For specific purposes, individual cells can also be cloned, creating tissue cultures that can grow indefinitely in suitable media. Cloned cells serve as a substitute for laboratory animals because they can be used to study the effects of various chemicals, such as drugs, on living organisms.

Plant cloning takes advantage of a unique feature of plant cells. In the early 60s. XX century it was shown for the first time that plant cells, even after reaching maturity and specialization, under suitable conditions are capable of giving rise to a whole plant (Fig. 110). Therefore, modern methods of cell engineering make it possible to select plants at the cellular level, i.e., select not adult plants that have certain properties, but cells from which full-fledged plants are then grown.

Rice. 109. Cloning Dolly the Sheep

Ethical aspects of biotechnology development. The use of modern biotechnologies poses many serious questions to humanity. Could a gene embedded in transgenic tomato plants, when the fruit is eaten, migrate and be integrated into the genome of, for example, bacteria living in the human intestine? Could a transgenic crop plant resistant to herbicides, diseases, drought and other stress factors, when cross-pollinated with related wild plants, transfer these same properties to weeds? Will this not result in “super weeds” that will very quickly colonize agricultural lands? Will giant salmon fry accidentally end up in the open sea and will this upset the balance in the natural population? Is the body of transgenic animals able to withstand the load that arises in connection with the functioning of foreign genes? And does a person have the right to remake living organisms for his own good?

These and many other issues related to the creation of genetically modified organisms are widely discussed by experts and the public around the world. Special regulatory bodies and commissions created in all countries claim that, despite existing concerns, no harmful effects of GMOs on nature have been recorded.

Rice. 110. Stages of plant cloning (using the example of carrots)

In 1996, the Council of Europe adopted the Convention on Human Rights in the Use of Genomic Technologies in Medicine. The document focuses on the ethics of using such technologies. It is argued that no individual can be discriminated against based on information about the characteristics of his genome.

Introducing foreign genetic material into human cells can have negative consequences. Uncontrolled integration of foreign DNA into certain parts of the genome can lead to disruption of gene function. The risk of using gene therapy when working with germ cells is much higher than when using somatic cells. When genetic constructs are introduced into germ cells, an undesirable change in the genome of future generations may occur. Therefore, international documents from UNESCO, the Council of Europe, and the World Health Organization (WHO) emphasize that any change in the human genome can only be made on somatic cells.

But perhaps the most serious questions arise in connection with the theoretically possible human cloning. Research in the field of human cloning is today prohibited in all countries, primarily for ethical reasons. The formation of a person as an individual is based not only on heredity. It is determined by the family, social and cultural environment, therefore, with any cloning, it is impossible to recreate a personality, just as it is impossible to reproduce all those conditions of upbringing and training that formed the personality of its prototype (nucleus donor). All major religious denominations in the world condemn any interference in the process of human reproduction, insisting that conception and birth must occur naturally.

Animal cloning experiments have raised a number of serious questions for the scientific community, the solution of which will determine the further development of this field of science. Dolly the sheep was not the only clone obtained by Scottish scientists. There were several dozen clones, and only Dolly remained alive. In recent years, improvements in cloning technology have allowed the percentage of surviving clones to increase, but their mortality rate is still very high. However, there is a problem that is even more serious from a scientific point of view. Despite Dolly's victorious birth, her real biological age, associated health problems and relatively early death remained unclear. According to scientists, the use of a cell nucleus from a middle-aged six-year-old donor sheep affected Dolly’s fate and health.

It is necessary to significantly increase the viability of cloned organisms, to find out whether the use of specific techniques affects the life expectancy, health and fertility of animals. It is very important to minimize the risk of defective development of the reconstructed egg.

The active introduction of biotechnology into medicine and human genetics has led to the emergence of a special science - bioethics. Bioethics– the science of ethical attitude towards all living things, including humans. Ethics standards are now coming to the fore. Those moral commandments that humanity has used for centuries, unfortunately, do not provide for the new opportunities brought into life by modern science. Therefore, people need to discuss and adopt new laws that take into account the new realities of life.

Review questions and assignments

1. What is biotechnology?

2. What problems does genetic engineering solve? What are the challenges associated with research in this area?

3. Why do you think the selection of microorganisms is becoming of paramount importance nowadays?

4. Give examples of the industrial production and use of waste products of microorganisms.

5. What organisms are called transgenic?

6. What is the advantage of cloning over traditional breeding methods?

Think! Do it!

1. What prospects does the use of transgenic animals offer in the development of the national economy?

2. Can modern humanity do without biotechnology? Organize an exhibition or make a wall newspaper “Biotechnology: past, present, future.”

3. Organize and lead a discussion on the topic “Cloning: pros and cons.”

4. Give examples of foods in your diet that were created using biotechnological processes.

5. Prove that biological water treatment is a biotechnological process.

Work with computer

Refer to the electronic application. Study the material and complete the assignments.

Cellular engineering. In the 70s In the last century, cell engineering began to actively develop in biotechnology. Cellular engineering makes it possible to create a new type of cell based on various manipulations, most often hybridization, i.e., the fusion of original cells or their nuclei. A nucleus belonging to a cell of another organism is placed in one of the cells being studied. Conditions are created under which these nuclei fuse, and then mitosis occurs, and two mononuclear cells are formed, each containing mixed genetic material. For the first time such an experiment was carried out in 1965 by the English scientist G. Harris, connecting human and mouse cells. Subsequently, entire organisms were obtained, which were interspecific hybrids obtained by cell engineering. Such hybrids differ from hybrids obtained sexually in that they contain the cytoplasm of both parents (remember that during normal fertilization, the cytoplasm of the sperm does not penetrate the egg). Cell fusion is used to produce hybrids with beneficial properties between distant species that do not normally interbreed. It is also possible to obtain plant cell hybrids that carry cytoplasmic genes (i.e., genes located in mitochondria and plastids), which increase resistance to various harmful influences.

Your future profession

1. What is the subject of study of the science of gerontology? Evaluate how developed this science is in our country. Are there specialists in this field in your region?

2. What personal qualities do you think people working in medical genetic consultations should have? Explain your point of view.

3. What do you know about the professions related to the material in this chapter? Find the names of several professions on the Internet and prepare a short (no more than 7-10 sentences) message about the profession that most impressed you. Explain your choice.

4. Using additional sources of information, find out what the embryologist studies. Where can you acquire such a specialty?

5. What knowledge should specialists involved in breeding work have? Explain your point of view.

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Genetic engineering - problems and achievements

Topic 4. Problems of fundamental science in ecology and environmental management

Modern problems of ecology as a science

Modern problems of geosciences

Geology

Geography

3.3. Soil science

1. Modern problems of biology as a science

Genetic engineering - problems and achievements

Genetic Engineering ( is stated according to... ). See also Appendix

Work on genetic reconstruction, or genetic engineering, began around the 70s of the 20th century, and the first reports of the production of modified genetically engineered eukaryotic organisms appeared in the middle. 80s

One of the main areas of biotechnology is the production and use of transgenic plants, i.e. forms that carry in their genome foreign genes inserted by genetic engineering methods that work normally in the new genome. The genes of animals, humans, bacteria, and other plants are integrated into the plant genome, which produce new products. In the future, this direction will be one of the most promising in terms of significantly improving the traits necessary for selection.

Improvement of plants through transgenesis proceeds in the following directions. The problem is most successfully solved herbicide resistance, which is important for combating weeds that clog fields and reduce the yield of cultivated plants. Herbicide-resistant varieties of cotton, corn, rapeseed, soybeans, sugar beets, wheat and other plants have been obtained and used.

It is around this direction of transgenesis that serious discussions have currently unfolded about the negative consequences of the transfer of herbicide resistance genes into cultivated plants. The possibility of spontaneous transfer of these genes into weeds is discussed, since hybridization and, consequently, gene transfer can occur between cultivated species and their accompanying wild relatives under certain conditions.

Plant resistance to insect pests– another problem successfully solved thanks to the introduction of transgenic plants. Most of the work on this problem is devoted to the protein deltaendotoxin, produced by different strains of the bacterium Bacillus turingensis. This protein is toxic to many species of insects and is safe for mammals, including humans. In a genome foreign to them, the bacterial genes began to function normally and produce a toxin, which, when the plants are eaten by insects, leads to their death.

One of the first commercial products of plant genetic engineering was the famous transgenic tomatoes with an almost unlimited shelf life. They were obtained in two companies using different methods. In the first case, a gene blocker (antisense construct) for an enzyme that plays a major role in the process of decomposition of tomato fruits was introduced into tomatoes. In another case, the gene for the synthesis of ethylene, a phytohormone that regulates fruit ripening, was blocked. The fruits of such transgenic plants can be stored indefinitely, up to forced treatment with ethylene, when it is necessary to obtain ripe fruits. (Has the release and consumption of these tomatoes so far not caused any negative consequences?)

Research aimed at obtaining proteins, antibodies, vaccines and other unique components of animal origin for medicine and veterinary medicine through transgenic plants is very promising. In these cases, human or animal genes are inserted into the plant genome, controlling the synthesis of protein components necessary for medicine. Thus, the plant turns into a kind of factory for the production of the products we need. In the same regard, work is underway to transform animals into donors of proteins, enzymes, hormones, antibodies, vaccines, etc. necessary for medicine and veterinary medicine. However, work on transgenic animals is fraught with great difficulties due to the specifics of the object and is so far less effective than work by plants.

If we evaluate the latest achievements of biotechnology from a methodological aspect, then we are undoubtedly talking about a serious intervention in the evolutionarily established genomes of plants, animals, and even humans themselves. All transgenesis, i.e. the introduction of foreign genes into the genome and their work in it is a serious genetic reconstruction, leading to the emergence of new functions, new genome products, which introduce a significant imbalance into the evolutionarily established mechanisms of interaction of both intragenomic and external systems. But man is forced to look for new approaches to creating fundamentally new organisms that meet his needs, since he is threatened by food shortages, as there is a threat to his health and environmental well-being. Having exhausted natural resources, man will have to begin creating artificial biological systems that provide him with the necessary components, but do not upset the ecological balance. All disputes and discussions lie precisely in this plane. They are aggravated by the fact that we do not yet know the consequences of our intervention in the genome, although research in this direction is being intensively conducted.

If it is possible to transfer individual genes of systematically distant species and make them work successfully, then why cannot larger genetic blocks – parts of chromosomes or entire chromosomes – be transferred. The field of cytogenetics, where these problems are solved, is called chromosome engineering. Methods and approaches to chromosome engineering have been successfully developed for a relatively long time on plants as the most convenient object for these purposes. The transfer of chromosomes or parts thereof from one genome to another is an even larger-scale reorganization of genomes. So far this has been successful only in plants, but attempts, already successful, are being made on animals. In this case, we are not talking about individual products of transferred genes, but about obtaining organisms that combine many characteristics of different species.

One of the most significant problems of modern natural science is problem of biology and genetics of organism development. A mystery for researchers are the mechanisms that form different types of cells, tissues, organs, i.e. responsible for the differentiation of body systems functioning as a single whole. Many researchers are working on this problem, focusing on the genetic aspects of differentiation. Hypotheses have emerged and interesting factual material has been accumulated. However, it appears that this problem is so complex that it will take many years to solve. The result of its solution - management of development processes can be extremely important.

Malignant formations are deviations in the normal development process due to the systems that control development, primarily genetic ones, going out of control. If we know the mechanisms of action of these systems, we will be able to control them and make the necessary correction at those stages that determine the normal type of development. There is every reason to believe that the most significant discoveries await us in this area of biology.

The next promising direction in the development of modern biology is the study complex physiological and genetic functions of the body. For plants this is photosynthesis, nitrogen fixation, etc., for animals - behavior, stress reactivity, etc. There is no need to explain what photosynthesis means for plants. Cells of green plants, some algae and bacteria are capable of synthesizing organic compounds using light energy. It is through photosynthesis that the process of self-reproduction of a significant part of biological resources occurs. Currently, many laboratories around the world are studying this complex process, dividing it into individual units, in order to then understand and reproduce this complex system as a whole. The genetics of photosynthesis is being studied especially intensively; about a hundred genes are already known that control individual parts of the process.

Another example of a complex physiological-genetic trait is animal behavior. The Institute of Cytology and Genetics of the SB RAS has been conducting an experiment on the domestication of foxes for 50 years. In the original population, animals were differentiated by types of behavior: aggressive, cowardly, calm towards humans, with subsequent selection from generation to generation. As a result, over 50 generations of selection, a new behavioral population of animals was created. This experiment reproduces in a condensed form the process of domestication of wild animals, which lasted thousands of years. It became clear that the most powerful selection factor in the domestication of wild animals was their behavior towards humans. The work carried out has shown that today it is extremely important to model the links of the evolutionary process in order to get closer to the reorganization of complex physiological functions - behavior, stress resistance, etc.

Narrow specialization in biology has now led to some weakening of cross-level research, and thereby to difficulties in understanding experimental data at the evolutionary-population level. This is a very serious drawback, since against the backdrop of enormous factual material, especially molecular genetic data, the evolutionary meaning of the phenomena being studied is often lost. It is very important to preserve the traditions of complex research, also because in addition to the main line of development of biology (molecule – cell – organism – population), there are many problems that arise at the intersection with other sciences. Interpretation of the data obtained in this case is even more complex and requires general natural science approaches. Examples of such interscientific integration programs may be the following:

1) assessment of anthropogenic (radiation, chemical, etc.) impacts on living systems over a large time range. Naturally, to study this problem, the efforts of biologists, doctors, physicists, chemists, etc. are needed;

2) ancient DNA research from archaeological samples several thousand years old in order to study several aspects of the evolution and variability of the human genome. Such a program is carried out by geneticists in collaboration with archaeologists and paleontologists;

3) creation of bioinformation technologies to study the structure and function of the genome. This work, carried out by biologists together with mathematicians, is acquiring priority importance today. Decoding the genomes of humans, animals and plants are multi-volume genetic texts, and it is possible to comprehend them and bring them into the state of fragments corresponding to genes only with the help of computer programs.

4) study of hereditary diseases(today more than 2 thousand of them are known), the genetic component of a person’s predisposition to the most common cancer, cardiovascular and many other diseases. This is also the task of many sciences.

The list of related problems and interdisciplinary, interscientific programs could be continued.