Population genetics. Theory of phylembryogenesis. Animal cloning has begun. Biology as a science. Biological (phagocytic) theory of immunity. Biology. Subject and objects of science. Methods biological science. The ability of barley extracts to convert starch into sugar. The term "biology". Development of fly larvae from laid eggs. Endoplasmic chain. The meaning of biology. Sciences are different from each other. New sciences.
“The main stages in the development of biology” - Hugo de Vries. Hippocrates. Creation cell theory. Scientific methods. Renaissance period. Short story biology. The study of a particular phenomenon through experience. "Genetic" period. The principle of “take nothing for granted.” The science. Comparison of facts. Stages of development of biology. Galen. Biology. The emergence of ancient states. Theophrastus. Collection of factual material. Identifying similarities and differences. Aristotle.
“History and methodology of biology” - Aristotle’s teaching about the three kinds of souls. Empedocles. Ionia. Ionian philosophers. Egypt. Herophilus. Aristotle "On the Parts of Animals." Asimov Isaac. Plato and Aristotle. The Greeks and their philosophy. Ideas about relationships between structures various organs and their functions. Anaximander. Aristotle. Aristotle "On the Origin of Animals." A Brief History of Biology. Democritus Aristotle's Ladder of Nature. The doctrine of the natural causes of disease.
“Stages of development of biology” - Hippocrates. Creation of cell theory. Main directions modern biology. Studying. Comparison of facts. The emergence of ancient states. Answer the questions. Fill the table. "Genetic" period. Descriptive science. Renaissance period. Collection of factual material. Scientific methods. Hugo de Vries. Galen. Theophrastus. Identifying similarities and differences between organisms. Sphere of human activity.
“A Brief History of Biology” - Cognitive models of biology. Embryology of invertebrates. Philosophical foundations of classical biology. The emergence of biology. Inductive-empirical method. Paradigms classical genetics. Evolutionary morphology of animals. Scientific schools. Molecular biology and reductionism. Cell theory. Physiology of humans and animals. Archeology of knowledge. Organismic paradigm. Theories of development of natural sciences.
“A brief history of the development of biology” - Ivan Pavlov. Arab scientists. Georges Cuvier. Leonardo da Vinci. Hippocrates. Drawings from the atlas of Vesalius. Charles Darwin. Aristotle. William Harvey. Claudius Galen. Review questions. Jean Baptiste Lamarck. Andreas Vesalius. Matthias Schleiden. Hippocratic Oath. Robert Koch at work. Achievements of modern biology. Drawings from da Vinci's atlas. Gregor Mendel. A brief history of the development of biology. Robert Koch.
Biology as a science, content, research methods. The importance of biology for medicine. Fundamental properties of living things. Evolutionarily determined levels of organization of living things.
Biology- life science. She studies life as special form movement of matter, the laws of its existence and development. The subject of studying biology is living organisms, their structure, functions, and their natural communities. The term “biology” was first proposed in 1802 by J. B. Lamarck. Together with astronomy, physics, chemistry, geology and other sciences that study nature, biology is one of the natural sciences.
Modern biology is a system of sciences about living nature. Biological sciences serve as the theoretical basis of medicine, agronomy, animal husbandry, as well as all those branches of production that are associated with living organisms.
Methods of biological sciences. The main private methods in biology are: descriptive, comparative, historical and experimental.
In order to find out the essence of phenomena, it is necessary first of all to collect factual material and describe it. Collecting and describing facts were the main method of research in the early period of the development of biology, which, however, has not lost its importance at the present time. The oldest of the methods. Made it possible to accumulate and systematize enormous factual material on botany, zoology, and anatomy.
Back in the 18th century. became widespread comparative method allowing, through comparison, to study the similarities and differences of organisms and their parts. Systematics was based on the principles of this method, and one of the largest generalizations was made - the cell theory was created. Application of the comparative method in anatomy, paleontology, embryology, which are often combined under common name the triple method of studying phylogeny, zoogeography, etc. contributed to the establishment of evolutionary concepts. The comparative method has developed into a historical one, but has not lost its significance even now.
Historical method clarifies the patterns of the appearance and development of organisms, the formation of their structure and function. Affirmation in biology historical method science owes Darwin.
Experimental method The study of natural phenomena is associated with active influence on them by setting up experiments (experiments) in precisely taken into account conditions and by changing the course of processes in necessary for the researcher direction. This method allows you to study phenomena in isolation and achieve their repeatability when reproducing identical conditions. The experiment provides not only deeper insight into the essence of phenomena than other methods, but also direct mastery of them. Highest form experiment is the modeling of the processes being studied.
The importance of biology for medicine:
Scientists of antiquity were outstanding biologists, but biology, as the theoretical basis of medicine, began to take shape in the 19th century.
1 ) Creation of cell theory by Schleiden and Schwann 1838
2 )The works of Pasteur and his followers, who studied microorganisms as causative agents of infectious diseases, laid the scientific foundations of infectious pathologies and accelerated the development of surgery.
3 ) The doctrine of immunity by I.I. Mechnikov 1896
4 ) Advances in genetics have made it possible to develop medical genetic counseling for the purpose of diagnosis, prevention, and treatment of hereditary diseases.
The importance of studying biology for a physician is determined by the fact that biology is, first of all, the basis of medicine. “Medicine, taken in terms of theory, is, first of all, general biology,” wrote one of the greatest theorists of medicine, I. V. Davydovsky (1887-1968). Advances in medicine are associated with biological research, so the doctor must constantly be aware of the latest achievements biology. It is enough to give a few examples from the history of science to be convinced of the close connection between the successes of medicine and discoveries in seemingly purely theoretical areas of biology. The research of L. Pasteur (1822-1895), published in 1862 and proving the impossibility of the spontaneous generation of life in modern conditions, the discovery of the microbial origin of the processes of decay and fermentation revolutionized medicine and ensured the development of surgery. Antiseptics were first introduced into practice (preventing wound infection by chemical substances), and then asepsis (preventing contamination by sterilizing objects that come into contact with the wound). This same discovery served as an incentive to search for the causative agents of infectious diseases, and their discovery is associated with the development of prevention and rational treatment.
The study of physiological and biochemical patterns, the discovery of cells and the study of the microscopic structure of organisms made it possible to better understand the causes of the disease process and contributed to the introduction of new diagnostic and treatment methods into practice. The latest research in the field of patterns of cell division and cell differentiation is directly related to both the problem of regeneration, i.e. restoration of damaged organs, and the problem of malignant growth and the fight against cancer.
Study by I. I. Mechnikov (1845-1916) of digestive processes in the lowest of multicellular organisms led to the discovery of phagocytosis and contributed to the explanation of the phenomena of immunity and the body's resistance to pathogens. AND modern ideas about immunity are based on biological research. Discovering the mechanisms of immunity is also necessary to overcome tissue incompatibility, a problem very important for reconstructive surgery, which is associated with issues of organ transplantation.
Research by I. I. Mechnikov on interspecies struggle in microorganisms were a prerequisite for the discovery of antibiotics used to treat many diseases, and the mass production of antibiotics became possible only through the use of genetic methods to create highly productive strains of antibiotic producers.
Soviet researcher B.P. Tokin discovered volatile substances in plants - phytoncides, which are widely used in medicine.
A large number of diseases are hereditary. Their prevention and treatment require knowledge of genetics. But non-hereditary diseases also develop differently and require different treatment depending on the genetic constitution of the person, which the doctor cannot fail to take into account. Many congenital
anomalies arise due to exposure to unfavorable environmental conditions. To prevent them is the task of a doctor armed with knowledge of the biology of the development of organisms.
Human health largely depends on the state of the environment. Knowledge of biological laws is necessary for a scientifically based attitude towards nature, the protection and use of its resources, including for the purpose of treating and preventing diseases.
Fundamental properties of living things.
The fundamental properties, the totality of which characterizes life, include: self-renewal, associated with the flow of matter and energy; self-reproduction ensuring continuity between successive generations of biological systems associated with the flow of information; self-regulation, based on the flow of matter, energy and information.
The listed fundamental properties determine the main attributes of life: metabolism and energy, irritability, homeostasis, reproduction, heredity, variability, individual and phylogenetic development, discreteness and integrity.
Metabolism and energy. Characterizing the phenomena of life, F. Engels wrote in his work “Dialectics of Nature”: “Life is a way of existence of protein bodies, the essential point of which is constant exchange of substances with the external nature surrounding them, and with the cessation of this metabolism life also ceases, which leads to the decomposition of protein.” At the same time, F. Engels noted that metabolism can also take place between bodies of inanimate nature. However, fundamentally, metabolism as a property of living things is qualitatively different from metabolic processes in non-living bodies. In order to show these differences, let's look at a number of examples.
A burning piece of coal is in a state of exchange with the surrounding nature, oxygen is included in chemical reaction and selection carbon dioxide. The formation of rust on the surface of an iron object is a consequence of exchange with the environment. But as a result of these processes inanimate bodies cease to be what they were. On the contrary, for bodies of living nature the exchange with environment is a condition of existence. In living organisms, metabolism leads to the restoration of destroyed components, replacing them with new ones similar to them, i.e., to self-renewal and self-reproduction, or the construction of the body of a living organism through the absorption of substances from the environment.
From the above it follows that organisms exist as open systems. Through each organism there is a continuous flow of matter and a flow of energy. The implementation of these processes is determined by the properties of proteins, especially their catalytic activity. Moreover, despite the continuous renewal of matter, structures in living things are preserved, or rather, continuously reproduced, which is associated with the information contained in nucleic acids. Nucleic acids have the property of storing and reproducing hereditary information, as well as realizing it through protein synthesis. Due to the fact that organisms are open systems, they are in unity with the environment, and the physical, chemical and biological properties of the environment determine the implementation of all life processes.
Irritability. This integral feature, characteristic of all living things, is an expression of one of general properties all bodies of nature - reflection properties. It is associated with the transfer of information from the external environment to any biological system (organism, organ, cell) and is manifested by the reactions of these systems to external influences. Thanks to this property, a balance between organisms and the external environment is achieved: organisms selectively react to environmental conditions, are able to extract from it everything necessary for their existence, and therefore, the metabolism, energy and information so characteristic of living organisms is associated with them. The property of irritability is associated with the chemical structure of the very substrate of life.
Obtaining the necessary information ensures self-regulation in biological systems, which is carried out according to the feedback principle. Waste products can have a strong and strictly specific inhibitory effect on those enzymes that form the initial link in a long chain of reactions. According to principle feedback the processes of metabolism, reproduction, reading of hereditary information, and therefore the manifestation of hereditary properties in individual development, etc. are regulated.
Self-regulation in organisms maintains the constancy of the structural organization - homeostasis. Organisms are characterized by constancy of chemical composition and physical and chemical characteristics. All living beings are characterized by the presence of mechanisms that maintain the constancy of the internal environment. Structural organization in the broad sense, i.e. a certain orderliness, is revealed not only in the study of life activity individual organisms. Organisms of different species, connected to each other by their habitat, constitute biocenoses (historically established communities). In biocenoses as a result of the exchange of substances, energy and information between organisms and their environment inanimate nature a certain biocenotic homeostasis is also maintained: constancy of the species composition and number of individuals of each species.
Biological systems at various levels of organization are characterized by adaptation. Adaptation refers to the adaptation of living things to continuously changing environmental conditions. Adaptation is based on the phenomena of irritability and its characteristic adequate responses. Adaptations have been developed in the process of evolution as a consequence of the survival of the fittest. Without adaptation it is impossible to maintain a normal existence.
Reproduction. Due to the fact that life exists in the form of separate (discrete) biological systems (cells, organisms, etc.) and the existence of each individual biological system is limited in time, maintaining life at any level is associated with reproduction. Any species consists of individuals, each of which will sooner or later cease to exist, but thanks to reproduction (reproduction), the life of the species does not cease. The reproduction of all species inhabiting the Earth maintains the existence of the biosphere. Self play on at the molecular level determines the metabolic characteristics of living organisms compared to nonliving bodies.
At the molecular level, reproduction is carried out on the basis of matrix synthesis. The principle of matrix synthesis is that new molecules are synthesized in accordance with the program inherent in the structure of pre-existing molecules. Matrix synthesis underlies the formation of protein molecules and nucleic acids.
Heredity ensures material continuity (flow of information) between generations of organisms. It is closely related to the reproduction (autoreproduction) of life at the molecular, subcellular and cellular levels. The storage and transmission of hereditary information is carried out by nucleic acids. Thanks to heredity, traits that ensure the adaptation of organisms to their environment are passed on from generation to generation.
Variability - a property opposite to heredity, associated with appearance of signs, different from typical ones. If during reproduction only the continuity of previously existing properties and characteristics were always manifested, then the evolution of the organic world would be impossible; But living nature is characterized by variability. First of all, it is associated with “errors” during reproduction. Newly constructed nucleic acid molecules carry new hereditary information. This new changed information in most cases is harmful to the body, but in some cases, as a result of variability, the body acquires new properties that are useful under given conditions. New characteristics are picked up and fixed by selection. This is how new forms, new species are created. Thus, hereditary variability creates the prerequisites for speciation and evolution, and thereby the existence of life.
Individual development. Organisms that appear as a result of reproduction do not inherit ready-made characteristics, but a certain genetic information, the possibility of developing certain signs. This hereditary information is realized during individual development. Individual development is expressed, as a rule, in an increase in mass (height), which, in turn, is based on the reproduction of molecules, cells and other biological structures, as well as differentiation, i.e. the appearance of differences in structure, complication of functions, etc. d.
Phylogenetic development , the main laws of which were established by Ch. Darvino.m, (1809-1882), is based on progressive reproduction, hereditary variability, the struggle for existence and selection. The action of these factors has led to a huge variety of life forms adapted to different environmental conditions. Progressive evolution has passed through a number of stages: precellular forms, unicellular organisms, increasingly complex multicellular organisms up to humans. However, along with the man appeared new form existence of matter - social, higher than biological and not reducible to it. Because of this, man, unlike all other creatures, is a biosocial organism.
Discreteness and integrity. Life is characterized by a dialectical unity of opposites: it is both holistic and discrete. Organic the world is whole, the existence of some organisms depends on others. In a very general and simplified form it can be represented as follows. Predatory animals require the existence of herbivores for their nutrition, and the latter require the existence of plants. During photosynthesis, plants absorb CO 2 from the atmosphere, the release of which into the atmosphere is associated with the vital activity of living organisms. In addition, plants receive a number of minerals from the soil, the amount of which is not depleted due to the decomposition of organic matter carried out by bacteria, etc.
Organic world it is integral, since it forms a system of interconnected parts, and at the same time discrete. It consists of units - organisms, or individuals. Every living organism is discrete, as it consists of organs, tissues, cells, but at the same time, each of the organs, having a certain autonomy, acts as part of the whole. Each cell consists of organelles, but functions as a single whole. Hereditary information is carried out by genes, but none of the genes outside the entire set determines the development of a trait, etc. Life is connected with molecules of proteins and nucleic acids, but only their unity, complete system determines the existence of living things.
Various levels of organization of the organic world are associated with the discreteness of life.
Level of organization of living things. In the middle of the twentieth century. in biology, ideas have developed about the levels of organization as a specific expression of order, which is one of the main properties of living things (biological microsystems: mol., subcellular, cellular; biological.mesosist.: mk., or., org.; biological.macros.: pop.-spec., biocenotic).
Living things on our planet are presented in the form of discrete units - organisms, individuals. Each organism, on the one hand, consists of units of subordinate levels of organization (organs, cells, molecules), on the other hand, it itself is a unit that is part of supraorganismal biological macrosystems (populations, biocenoses, the biosphere as a whole).
At all levels of life, such attributes as discreteness and integrity, structural organization (orderliness), metabolism, energy and information, etc. appear. The nature of the manifestation of the basic properties of life at each level has quality features, orderliness. As is known, as a result of metabolism, energy and information, the unity of living things and the environment is established, but the concept of environment for different levels various. For discrete units of the molecular and supramolecular (subcellular) levels, the environment is the internal environment of the cell; for cells, tissues and organs - the internal environment of the body. External live and inanimate environment at these levels of the organization is perceived through change internal environment, i.e. indirectly. For organisms (individuals) and their communities, the environment consists of organisms of the same and other species and the conditions of inanimate nature.
The existence of life at all levels is prepared and determined by the structure of the lower level. The nature of the cellular level of organization is determined by the molecular and subcellular levels, the organism - cellular, tissue, organ, species (population) - organism, etc. It should be noted that there is a great similarity of discrete units at lower levels and an ever-increasing difference at higher levels.
Molecular level. On molecular level an amazing monotony of discrete units is revealed. The living substrate for all animals, plants, and viruses is only 20 of the same amino acids and 4 of the same nitrogenous bases that make up the nucleic acid molecules. Lipids and carbohydrates have a similar composition. In all organisms, biological energy is stored in the form of energy-rich adenosine phosphoric acids (ATP, ADP, AMP). Everyone's hereditary information is contained in DNA molecules (the only exceptions are RNA-containing viruses), which are capable of self-reproduction. Implementation hereditary information carried out with the participation of RNA molecules synthesized on template DNA molecules. Due to the fact that with molecular structures storage, modification and implementation of hereditary information is associated; this level is sometimes called molecular genetic.
Cellular level. At the cellular level, the same type of all living organisms is also noted. The cell is the basic independently functioning elementary biological unit, characteristic of all living organisms. In all organisms, the biosynthesis and implementation of hereditary information is not possible only at the cellular level. The cellular level in unicellular organisms coincides with the organismal level. There was a period in the history of life on our planet (the first half of the Archean era) when all organisms were at this level of organization. All species, biocenoses and the biosphere as a whole consisted of such organisms.
Tissue level. A collection of cells with the same type of organization constitutes a tissue. The tissue level arose along with the emergence of multicellular animals and plants with differentiated tissues. In multicellular organisms it develops during ontogenesis. Great similarity between all organisms remains at the tissue level. Cells that function together and belong to different tissues make up organs. Only 5 main tissues are part of the organs of all multicellular animals, and 6 main tissues form the organs of plants.
Organismal (ontogenetic) level. On organismal level a difficult-to-see variety of forms is revealed. The diversity of organisms belonging to different species, and even within the same species, is not a consequence of the diversity of discrete units of a lower order, but of their increasingly complex spatial combinations, which determine new qualitative features. Currently, more than a million species of animals and about half a million species of higher plants live on Earth. Each species consists of separate individuals.
An individual - an organism as a whole - is an elementary unit of life. Life does not exist outside of individuals in nature. Ontogenesis processes occur at the organismal level, therefore this level is also called ontogenetic. The nervous and humoral systems carry out self-regulation in the body and determine a certain homeostasis.
Population-species level. A set of organisms (individuals) of the same species inhabiting a certain territory, interbreeding freely with each other, constitutes a population. Population is an elementary unit evolutionary process; the processes of speciation begin in it. The population is part of biogeocenoses.
Biocenotic and biosphere levels. Biogeocenoses are historically established stable communities of populations of different species, connected with each other and with the surrounding inanimate nature by metabolism, energy and information. They are elementary systems in which the material-energy cycle occurs, determined by the vital activity of organisms. Biogeocenoses make up the biosphere and determine all the processes occurring in it.
Only with a comprehensive study of the phenomena of life at all levels can one obtain a holistic understanding of the special (biological) form of existence of matter.
The idea of the levels of organization of life is directly related to the basic principles of medicine. It forces us to look at the healthy and sick human body as an integral, but at the same time complex, hierarchically subordinate system of organization. Knowledge of the structures and functions of each of them helps to reveal the essence of the disease process. Taking into account the human population to which a given individual belongs may be required, for example, when diagnosing a hereditary disease. To reveal the characteristics of the course of the disease and the epidemic process, it is also necessary to take into account the characteristics of the biocenotic and social environment. Whether a doctor is dealing with an individual patient or a human group, he is always based on a complex of knowledge obtained at all levels of biological micro-, meso- and macrosystems.
Ionizing radiation as a factor in the environment. Kinds ionizing radiation. Penetrating and ionizing ability of ionizing radiation. Biological effects ionizing radiation. Radiation hormesis.
Solar radiation is one of the most important abiotic factors environment and is one of the factors that played a key historical role in the evolution of the biosphere. This evolution, according to figuratively Yu. Odum, was aimed at “taming” the incoming solar radiation, the use of its beneficial components, the weakening of harmful ones and protection from them. Thus, light is not only a vitally important factor, but also a limiting one, both at the maximum and minimum levels.
Sunlight is electromagnetic radiation with various wavelengths from 0.05 to 3000 nm and more. This flow can be divided into several areas that differ physical properties and environmental significance for various groups organisms:
<150 нм зона ионизирующей радиации
150 – 400 nm ultraviolet radiation
400 - 800 nm visible light
800 – 1000 nm infrared radiation
>1000 nm is the so-called far-infrared radiation zone – a powerful factor thermal regime environment.
The science that studies the responses of biological objects and systems to the action of ionizing radiation is called radiobiology.
Its founders were:
X-ray V.K. 1895 cathode rays (X-rays) cause the barium cyanoplatinite-coated screen to fluoresce. First x-ray of your hand
Becquerel A.A. spontaneous emission of penetrating radiation invisible to the eye (α-, β- and γ-radiation) emanating from uranium salts; 1900 radioactive rays partially composed of electrons
Marie Skladovskaya-Curie, Pierre Curie thorium emits “Becquerel rays”, 2 new radioactive elements (polonium and radium) 1898; emission of "Becquerel rays" - radioactivity