Biological sciences and their definitions briefly. What are the biological sciences?

Biology (from the Greek words βίος - life and λόγος - science) is a set of sciences about living nature. Biology studies all manifestations of life, the structure and functions of living beings and their communities, the distribution, origin and development of living organisms, their connections with each other and with inanimate nature.

Living nature is characterized by different levels of organization of its structures, between which there is a complex subordination. All living organisms along with environment form a biosphere, which consists of biogeocenoses. These, in turn, include biocenoses consisting of populations. Populations are made up of individuals. Individuals of multicellular organisms consist of organs and tissues formed by various cells. Each level of life organization has its own patterns. Life at each level is studied by the corresponding branches of modern biology.

To study living nature, biologists use various methods: observation, which allows one to describe a particular phenomenon; comparison, which makes it possible to establish patterns common to different phenomena in living nature; experiment, or experiment, when the researcher himself artificially creates a situation that helps to identify certain properties of biological objects. The historical method allows, on the basis of data about the modern organic world and its past, to understand the processes of development of living nature. In addition to these basic methods, many others are used.

Roman physician and naturalist Claudius Galen.

Renaissance scientist, anatomist and surgeon Andreas Vesalius.

The English physician and scientist William Harvey talks about his experiments on blood circulation to the English king Charles I.

Robert Hooke's microscope (60s of the 17th century).

This is what cork sections looked like under R. Hooke’s microscope. This was the first image of cells.

Drawings of plant cells made by a 17th-century Dutch biologist. Anthony van Leeuwenhoek.

Biology has its origins in ancient times. Descriptions of animals and plants, information about the anatomy and physiology of humans and animals were necessary for practical activities of people. Some of the first attempts to comprehend and systematize the phenomena of life, to generalize accumulated biological knowledge and ideas were made by the ancient Greek and later Roman scientists and doctors Hippocrates, Aristotle, Galen and others. These views, developed by Renaissance scientists, laid the foundation for modern botany and zoology, anatomy and physiology, and other biological sciences.

In the XVI-XVII centuries. V scientific research Along with observation and description, experiment began to be widely used. At this time, anatomy achieves brilliant success. In the works of famous scientists of the 16th century. A. Vesalius and M. Servetus laid the foundations for ideas about the structure of the circulatory system of animals. This paved the way for the great discovery of the 17th century. - the doctrine of blood circulation created by the Englishman W. Harvey (1628). A few decades later, the Italian M. Malpighi discovered capillaries using a microscope, which made it possible to understand the path of blood from arteries to veins.

The creation of the microscope expanded the possibilities of studying living beings. Discoveries followed one after another. The English physicist R. Hooke discovered the cellular structure of plants, and the Dutchman A. Leeuwenhoek discovered single-celled animals and microorganisms.

In the 18th century A lot of knowledge about living nature has already been accumulated. There is a need to classify all living organisms and bring them into a system. At this time, the foundations of the science of taxonomy were laid. The most important achievement in this area was the “System of Nature” by the Swedish scientist C. Linnaeus (1735).

Physiology, the science of the vital functions of organisms, their individual systems, organs and tissues, and the processes occurring in the body, received further development.

The Englishman J. Priestley showed in experiments on plants that they emit oxygen (1771-1778). Later, the Swiss scientist J. Senebier established that plants, under the influence of sunlight, absorb carbon dioxide and release oxygen (1782). These were the first steps towards studying the central role of plants in the transformation of substances and energy in the Earth's biosphere, the first step in a new science - plant physiology.

A. Lavoisier and other French scientists discovered the role of oxygen in animal respiration and the formation of animal heat (1787-1790). At the end of the 18th century. Italian physicist L. Galvani discovered “animal electricity,” which later led to the development of electrophysiology. At the same time, the Italian biologist L. Spallanzani conducted precise experiments that disproved the possibility of spontaneous generation of organisms.

In the 19th century In connection with the development of physics and chemistry, new research methods are penetrating biology. The richest material for studying nature was provided by land and sea expeditions to previously inaccessible areas of the Earth. All this led to the formation of many special biological sciences.

At the turn of the century, paleontology emerged, the study of fossil remains of animals and plants - evidence of successive changes - the evolution of life forms in the history of the Earth. Its founder was the French scientist J. Cuvier.

Embryology, the science of the embryonic development of an organism, has received great development. Back in the 17th century. W. Harvey formulated the position: “Everything that lives comes from an egg.” However, only in the 19th century. Embryology became an independent science. Particular credit for this belongs to the natural scientist K. M. Baer, who discovered the egg of mammals and discovered the commonality of the structural plan of the embryos of animals of different classes.

As a result of the achievements of biological sciences in the first half of the 19th century. The idea of the kinship of living organisms and their origin in the course of evolution became widespread. The first holistic concept of evolution - the origin of animal and plant species as a result of their gradual change from generation to generation - was proposed by J. B. Lamarck.

The largest scientific event of the century was the evolutionary doctrine of Charles Darwin (1859). Darwin's theory had a huge impact on everything further development biology. New discoveries are being made that confirm Darwin’s correctness in paleontology (V. O. Kovalevsky), in embryology (A. O. Kovalevsky), in zoology, botany, cytology, and physiology. Spreading evolutionary theory on ideas about the origin of man led to the creation of a new branch of biology - anthropology. Based on evolutionary theory, German scientists F. Müller and E. Haeckel formulated the biogenetic law.

Another outstanding achievement of biology of the 19th century. - creation by the German scientist T. Schwann of the cellular theory, which proved that all living organisms consist of cells. Thus, the commonality of not only the macroscopic (anatomical), but also the microscopic structure of living beings was established. This is how another biological science arose - cytology (the science of cells) and, as a consequence, the study of the structure of tissues and organs - histology.

As a result of the discoveries of the French scientist L. Pasteur (microorganisms cause alcoholic fermentation and cause many diseases), microbiology became an independent biological discipline. Pasteur's work finally refuted the idea of the spontaneous generation of organisms. The study of the microbial nature of avian cholera and mammalian rabies led Pasteur to the creation of immunology as an independent biological science. A significant contribution to its development was made by late XIX V. Russian scientist I. I. Mechnikov.

In the second half of the 19th century. many scientists tried to speculatively solve the riddle of heredity and reveal its mechanism. But only G. Mendel managed to establish experimentally the laws of heredity (1865). This is how the foundations of genetics were laid, which became an independent science already in the 20th century.

At the end of the 19th century. great strides have been made in biochemistry. The Swiss physician F. Miescher discovered nucleic acids (1869), which, as was later established, perform the functions of storing and transmitting genetic information. By the beginning of the 20th century. it was found that proteins consist of amino acids connected to each other, as the German scientist E. Fischer showed, by peptide bonds.

Physiology in the 19th century. develops into different countries peace. Particularly significant were the works of the French physiologist C. Bernard, who created the doctrine of the constancy of the internal environment of the body - homeostasis. In Germany, the progress of physiology is associated with the names of I. Müller, G. Helmholtz, E. Dubois-Reymond. Helmholtz developed the physiology of the sense organs, Dubois-Reymond became the founder of the study of electrical phenomena in physiological processes. Outstanding contribution to the development of physiology in the late 19th - early 20th centuries. contributed by Russian scientists: I. M. Sechenov, N. E. Vvedensky, I. P. Pavlov, K. A. Timiryazev.

Genetics emerged as an independent biological science that studies the heredity and variability of living organisms. It also followed from Mendel’s works that there were material units of heredity, later called genes. This discovery of Mendel was appreciated only at the beginning of the 20th century. as a result of research by H. De Vries in Holland, E. Chermak in Austria, K. Correns in Germany. American scientist T. Morgan, examining the giant chromosomes of the Drosophila fly, came to the conclusion that genes are located in cell nuclei, in chromosomes. He and other scientists developed the chromosomal theory of heredity. Thus, genetics was largely combined with cytology (cytogenetics) and the biological meaning of mitosis and meiosis became clear.

Since the beginning of our century, the rapid development of biochemical research has begun in many countries of the world. The main attention was paid to the pathways of transformation of substances and energy in intracellular processes. It was found that these processes are, in principle, the same in all living beings - from bacteria to humans. Adenosine triphosphoric acid (ATP) turned out to be a universal mediator in the transformation of energy in the cell. Soviet scientist V.A. Engelhardt discovered the process of ATP formation when cells absorb oxygen. The discovery and research of vitamins, hormones, and the establishment of the composition and structure of all the main chemical components of the cell have brought biochemistry to one of the leading places among the biological sciences.

At the turn of the 19th and 20th centuries. Professor of Moscow University A.A. Kolli raised the question of the molecular mechanism of inheritance of traits. The answer to the question was given in 1927 by the Soviet scientist N.K. Koltsov, putting forward the matrix principle of encoding genetic information (see Transcription, Translation).

The matrix coding principle was developed by the Soviet scientist N.V. Timofeev-Resovsky and the American scientist M. Delbrück.

In 1953, the American J. Watson and the Englishman F. Crick used this principle to analyze the molecular structure and biological functions of deoxyribonucleic acid (DNA). Thus, on the basis of biochemistry, genetics and biophysics, an independent science arose - molecular biology.

In 1919, the world's first Institute of Biophysics was founded in Moscow. This science studies the physical mechanisms of energy and information transformation in biological systems. A significant problem in biophysics is elucidating the role of various ions in the life of a cell. The American scientist J. Loeb and the Soviet researchers N.K. Koltsov and D.L. Rubinstein worked in this direction. These studies led to the establishment of the special role of biological membranes. The nonequilibrium distribution of sodium and potassium ions on both sides of the cell membrane, as shown by English scientists A. L. Hodgkin, J. Eckle and A. F. Huxley, is the basis for the propagation of a nerve impulse.

Significant successes have been achieved by the sciences studying individual development organisms - Ontogenesis. In particular, methods of artificial parthenogenesis were developed.

In the first half of the 20th century. Soviet scientist V.I. Vernadsky created the doctrine of the Earth's biosphere. At the same time, V.N. Sukachev laid the foundations for ideas about biogeocenoses.

The study of the interaction of individuals and their communities with the environment led to the formation of ecology - the science of the patterns of relationships between organisms and their environment (the term “ecology” was proposed in 1866 by the German scientist E. Haeckel).

Ethology, which studies animal behavior, has become an independent biological science.

In the 20th century The theory of biological evolution was further developed. Thanks to the development of paleontology and comparative anatomy, the origin of most large groups of the organic world was clarified, and the morphological patterns of evolution were revealed (Soviet scientist A. N. Severtsov). Of great importance for the development of evolutionary theory was the synthesis of genetics and Darwinism (the work of the Soviet scientist S. S. Chetverikov, English scientists S. Wright, R. Fisher, J. B. S. Haldane), which led to the creation of modern evolutionary teaching. The works of American scientists F. G. Dobzhansky, E. Mayr, J. G. Simpson, the Englishman J. Huxley, Soviet scientists I. I. Shmalhausen, N. V. Timofeev-Resovsky, and the German scientist B. Rensch are dedicated to him.

Plant physiology has made progress in understanding the nature of photosynthesis, studying the pigments involved in it, and above all chlorophyll.

With the exit of a person into space A new science has emerged - space biology. Its main task is to provide life support for people during space flight, to create artificial closed biocenoses on spaceships and stations, to search for possible manifestations of life on other planets, as well as suitable conditions for its existence.

In the 70s a new branch of molecular biology has arisen - genetic engineering, the task of which is the active and targeted restructuring of the genes of living beings, their design, i.e. control of heredity. As a result of this work, it became possible to introduce genes taken from one organism or even artificially synthesized into the cells of other organisms (for example, the introduction of a gene encoding the synthesis of insulin in animals into bacterial cells). Cell hybridization became possible different types- cellular engineering. Methods have been developed that make it possible to grow organisms from individual cells and tissues (see Cell and Tissue Culture). This opens up enormous prospects for the reproduction of copies - clones of valuable individuals.

All these achievements are of extremely important practical importance - they became the basis of a new branch of production - biotechnology. The biosynthesis of drugs, hormones, vitamins, and antibiotics is already being carried out on an industrial scale. And in the future, in this way we will be able to obtain the main components of food - carbohydrates, proteins, lipids. The use of solar energy based on the principle of plant photosynthesis in bioengineering systems will solve the problem of providing energy to the basic needs of people.

The importance of biology today has increased immeasurably and in connection with the problem of preserving the biosphere due to the rapid development of industry, Agriculture, the growth of the world's population. An important practical direction of biological research has emerged - the study of the human environment in a broad sense and the organization on this basis of rational methods of managing the national economy and nature conservation.

Another important practical significance of biological research is its use in medicine. It was the successes and discoveries in biology that determined the modern level of medical science. Further progress in medicine is also associated with them. You will read about many tasks of biology related to human health in our encyclopedia (see Immunity, Bacteriophage, Heredity, etc.).

Biology today is becoming a real productive force. By the level of biological research one can judge the material and technical development of society.

The accumulation of knowledge in new and classical areas of biology is facilitated by the use of new methods and instruments, for example, the advent of electron microscopy.

There is a growing number of biological research institutes, biological stations, as well as nature reserves and national parks, which play an important role as “natural laboratories”.

A large number of biologists of various specialties are trained by higher educational institutions (see Biological education). Many of you will in the future join a large team of specialists who are faced with the task of solving important biological problems.

The first major biological science is botany. She studies plants. Botany is divided into many disciplines that can also be considered biological. Algology. Plant anatomy studies the structure of plant tissues and cells, as well as the laws by which these tissues develop. Bryology studies bryophytes, dendrology studies woody plants. Carpology studies the seeds and fruits of plants.

Lichenology is the science of lichens. Mycology is about mushrooms, mycogeorgaphy is about their distribution. Paleobotany is a branch of botany that studies the fossil remains of plants. Palynology studies pollen grains and plant spores. The science of plant taxonomy deals with their classification. Phytopathology studies various plant diseases caused by pathogenic and environmental factors. Floristry studies flora, a collection of plants historically formed in a certain territory.

The science of ethnobotany studies the interactions between people and plants. Geobotany is the science of the Earth's vegetation. plant communities– phytocenoses. The geography of plants studies the patterns of their distribution. Plant morphology is the science of patterns. Plant physiology is about the functional activity of plant organisms.

Zoology and microbiology

Ichthyology is the science of fish, carcinology is of crustaceans, ketology is of cetaceans, conchiology is of mollusks, myrmecology is of ants, nematology is of roundworms, oology is of animal eggs, ornithology is of birds. Paleozoology studies the fossil remains of animals, planktology studies plankton, primatology studies primates, theriology studies mammals and insects, protozoology studies unicellular organisms. Ethology deals with the study.

The third major branch of biology is microbiology. This science studies living organisms invisible to the naked eye: bacteria, archaea, microscopic fungi and algae, viruses. Sections are distinguished accordingly: virology, mycology, bacteriology, etc.

Currently, biology includes a number of sciences that can be systematized according to the following criteria: subject and predominant methods research and on the subject being studied level of organization of living nature. According to the subject of study, biological sciences are divided into bacteriology, botany, virology, zoology, and mycology.

Botany is a biological science that comprehensively studies plants and the Earth's vegetation cover. Zoology- a branch of biology, the science of the diversity, structure, life activity, distribution and relationship of animals with their environment, their origin and development. Bacteriology- biological science that studies the structure and activity of bacteria, as well as their role in nature. Virology- biological science that studies viruses. Main object mycology are mushrooms, their structure and features of life. Lichenology- biological science that studies lichens. Bacteriology, virology and some aspects of mycology are often discussed as part of microbiology- section of biology, the science of microorganisms (bacteria, viruses and microscopic fungi). Taxonomy, or taxonomy,- biological science that describes and classifies into groups all living and extinct creatures.

In turn, each of the listed biological sciences is divided into biochemistry, morphology, anatomy, physiology, embryology, genetics and systematics (plants, animals or microorganisms). Biochemistry is the science of the chemical composition of living matter, the chemical processes occurring in living organisms and underlying their life activity. Morphology- biological science that studies the form and structure of organisms, as well as the patterns of their development. In a broad sense, it includes cytology, anatomy, histology and embryology. Distinguish between the morphology of animals and plants. Anatomy is a branch of biology (more precisely, morphology), a science that studies the internal structure and shape of individual organs, systems and the organism as a whole. Plant anatomy is considered as part of botany, animal anatomy is considered as part of zoology, and human anatomy is a separate science. Physiology- biological science that studies the life processes of plant and animal organisms, their individual systems, organs, tissues and cells. There is physiology of plants, animals and humans. Embryology (developmental biology)- a branch of biology, the science of the individual development of an organism, including the development of the embryo.

Object genetics are the laws of heredity and variability. Currently, it is one of the most dynamically developing biological sciences.

According to the level of organization of living nature being studied, molecular biology, cytology, histology, organology, biology of organisms and superorganismal systems are distinguished. Molecular biology is one of the youngest branches of biology, a science that studies, in particular, the organization of hereditary information and protein biosynthesis. Cytology, or cell biology,- biological science, the object of study of which is the cells of both unicellular and multicellular organisms. Histology- biological science, a branch of morphology, the object of which is the structure of tissues of plants and animals. To the sphere organology include the morphology, anatomy and physiology of various organs and their systems.

Organismal biology includes all sciences that deal with living organisms, e.g. ethology- the science of behavior of organisms.

The biology of supraorganismal systems is divided into biogeography and ecology. Studies the distribution of living organisms biogeography, whereas ecology- organization and functioning of supraorganismal systems at various levels: populations, biocenoses (communities), biogeocenoses (ecosystems) and the biosphere.

According to the prevailing research methods, we can distinguish descriptive (for example, morphology), experimental (for example, physiology) and theoretical biology.

Identifying and explaining the patterns of structure, functioning and development of living nature at various levels of its organization is a task general biology. It includes biochemistry, molecular biology, cytology, embryology, genetics, ecology, evolutionary science and anthropology. Evolutionary doctrine studies the causes, driving forces, mechanisms and general patterns evolution of living organisms. One of its sections is paleontology- a science whose subject is the fossil remains of living organisms. Anthropology- a section of general biology, the science of the origin and development of humans as a biological species, as well as the diversity of modern human populations and the patterns of their interaction.

Applied aspects of biology are included in the field of biotechnology, breeding and other rapidly developing sciences. Biotechnology is the biological science that studies the use of living organisms and biological processes in production. It is widely used in the food (baking, cheese-making, brewing, etc.) and pharmaceutical industries (production of antibiotics, vitamins), for water purification, etc. Selection- the science of methods for creating breeds of domestic animals, varieties of cultivated plants and strains of microorganisms with necessary for a person properties. Selection is also understood as the process of changing living organisms, carried out by humans for their needs.

The progress of biology is closely related to the successes of other natural and exact sciences, such as physics, chemistry, mathematics, computer science, etc. For example, microscopy, ultrasound (ultrasound), tomography and other methods of biology are based on physical laws, and the study of the structure of biological molecules and processes occurring in living systems would be impossible without the use of chemical and physical methods. Application mathematical methods allows, on the one hand, to identify the presence of a natural connection between objects or phenomena, to confirm the reliability of the results obtained, and, on the other hand, to model a phenomenon or process. IN Lately Computer methods, such as modeling, are becoming increasingly important in biology. At the intersection of biology and other sciences, a number of new sciences arose, such as biophysics, biochemistry, bionics, etc.

Biological sciences and the aspects they study. Anatomy is the science of the internal structure of the body. Genetics is about heredity and variability. Embryology is the science of the embryonic development of an organism. Histology is the science of tissue structure. Cytology is the science of the structure of cell life. Morphology is the science of external structure body. Physiology is a science that studies life processes. Zoology is the science of animals. Botany is the science of plants. Microbiology is the science of bacteria and viruses.

Slide 7 from the presentation "Biology". The size of the archive with the presentation is 1990 KB.

Biology 10th grade

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“Reproduction methods” - Reproduction by spores. Reproduction by division. Formation of germ cells. Types of asexual reproduction. Sporulation. Sexual reproduction. Individuals identical to the original organism. Asexual reproduction. Vegetative propagation. Reproduction. The ability to combine genetic material. The disappearance of sexual reproduction.

“Theories of the origin of living things” - Mine best lesson. Chemical evolution transition diagram. Nebula. The problem of nature. Theories of origin. Rules of judicial ethics. History of performances. Stages of emergence solar system. Lesson structure. History of ideas about the origin of life. Group work in the lesson. The work of judges. Hypotheses about the origin of life. Matter. Lesson stage. Modern hypotheses. Debate. Game regulations. Additional question.

"Inorganic compounds of the cell" - Chemical elements cells. Chemical composition cells. Functions of water. Polarity of membranes of living cells. Included in water. Protein component. Composition of blood plasma. Exercise. Chemical substances. Note the properties of water. Highlight the characteristic properties. Properties of water. Macroelements. Substances. Dipole structure.

“Problems of the emergence of life on Earth” - The emergence of multicellular organisms. Conditions for the emergence of primitive living beings. History of carbon. Coacervate droplets. The emergence of primary organisms. Works by L. Pasteur. Theories of the origin of life. Development of life. History of ideas about the origin of life. The emergence of life on Earth. From carbon to proteins. Representations of ancient and medieval philosophers. Age of the Earth. Possibility of occurrence of complex organic compounds.

“Population dynamics” - A single-celled amoeba divides into two cells every three hours. Rare species. Dictionary. Survival curves. Mathematical and computer modelling. Malthus's Law. Population development models. Environmental strategy. Predator-prey model. Anthropogenic impact on growth types. Types of population growth. Graphs of changes in population numbers. Lesson plan. R-strategists. Population density. Which species have stable population dynamics.

“Viruses in the body” - Due to the high mutability of viruses, the treatment of viral diseases is quite difficult. Viral diseases. Structure and classification of viruses. Viruses are the causative agents of many dangerous diseases of humans, animals and plants. Viruses are hereditary. The first mention of smallpox in Russia dates back to the 4th century. Attempts to use viruses for the benefit of humanity are quite few. Like other organisms, viruses are capable of reproduction.

Biology (from the Greek words bios - life and logos - science) is a set of sciences about living nature. Biology studies all manifestations of life, the structure and functions of living beings and their communities, the distribution, origin and development of living organisms, their connections with each other and with inanimate nature.

Living nature is characterized by different levels of organization of its structures, between which there is a complex subordination. All living organisms, together with the environment, form the biosphere, which consists of biogeocenoses. These, in turn, include biocenoses consisting of populations. Populations are made up of individuals. Individuals of multicellular organisms consist of organs and tissues formed by various cells. Each level of life organization has its own patterns. Life at each level is studied by the corresponding branches of modern biology.

Biology has its origins in ancient times. Descriptions of animals and plants, information about the anatomy and physiology of humans and animals were necessary for the practical activities of people. Some of the first attempts to comprehend and systematize the phenomena of life, to generalize accumulated biological knowledge and ideas were made by the ancient Greek and later Roman scientists and doctors Hippocrates, Aristotle, Galen and others. These views, developed by Renaissance scientists, laid the foundation for modern botany and zoology, anatomy and physiology, and other biological sciences.

In the XVI-XVII centuries. In scientific research, along with observation and description, experiment began to be widely used. At this time, anatomy achieves brilliant success. In the works of famous scientists of the 16th century. A. Vesalius and M. Servetus laid the foundations for ideas about the structure of the circulatory system of animals. This paved the way for the great discovery of the 17th century. - the doctrine of blood circulation created by the Englishman W. Harvey (1628). A few decades later, the Italian M. Malpighi discovered capillaries using a microscope, which made it possible to understand the path of blood from arteries to veins.

In the 18th century A lot of knowledge about living nature has already been accumulated. There is a need to classify all living organisms and bring them into a system. At this time, the foundations of the science of systematics were laid. The most important achievement in this area was the “System of Nature” by the Swedish scientist C. Linnaeus (1735).

Physiology, the science of the vital functions of organisms, their individual systems, organs and tissues, and the processes occurring in the body, received further development.

The Englishman J. Priestley showed in experiments on plants that they release oxygen (1771 -1778). Later, the Swiss scientist J. Senebier established that plants, under the influence of sunlight, absorb carbon dioxide and release oxygen (1782). These were the first steps towards studying the central role of plants in the transformation of substances and energy in the Earth's biosphere, the first step in a new science - plant physiology.

Embryology, the science of the embryonic development of an organism, has received great development. Back in the 17th century. W. Harvey formulated the position: “Everything that lives comes from an egg.” However, only in the 19th century. Embryology became an independent science. Particular credit for this belongs to the natural scientist K. M. Baer, who discovered the egg of mammals and discovered the common structure of the embryos of animals of different classes.

The largest scientific event of the century was the evolutionary doctrine of Charles Darwin (1859). Darwin's theory had a huge influence on the entire further development of biology. New discoveries are being made that confirm Darwin’s correctness in paleontology (A. O. Kovalevsky), in embryology (A. O. Kovalevsky), in zoology, botany, cytology, and physiology. The extension of evolutionary theory to ideas about human origins led to the creation of a new branch of biology - anthropology. Based on evolutionary theory, German scientists F. Müller and E. Haeckel formulated biogenetic law.

Another outstanding achievement of biology of the 19th century. - the creation by the German scientist T. Schwann of the cellular theory, which proved that all living organisms are composed of cells. Thus, the commonality of not only the macroscopic (anatomical), but also the microscopic structure of living beings was established. This is how another biological science arose - cytology (the science of cells) and, as a consequence, the study of the structure of tissues and organs - histology.

He made a significant contribution to its development at the end of the 19th century. Russian scientist I. I. Mechnikov.

In the second half of the 19th century. Many scientists tried to speculatively solve the riddle of heredity and reveal its mechanism. But only G. Mendel managed to establish experimentally the laws of heredity (1865). This is how the foundations of genetics were laid, which became an independent science already in the 20th century.

At the end of the 19th century. Mitosis was discovered - cell division with precise and equal division of chromosomes between daughter cells and meiosis - the formation of haploid germ cells from diploid cells with a double set of chromosomes - gametes with a single set of chromosomes.

The discovery of viruses by the Russian scientist D.I. Ivanovsky (1892) was of great importance.

Physiology in the 19th century. is developing in different countries of the world. Particularly significant were the works of the French physiologist C. Bernard, who created the doctrine of the constancy of the internal environment of the body - homeostasis. In Germany, the progress of physiology is associated with the names of I. Müller, G. Helmholtz, E. Dubois-Reymond. Helmholtz developed the physiology of the sense organs, Dubois-Reymond became the founder of the study of electrical phenomena in physiological processes. Outstanding contribution to the development of physiology in the late 19th - early 20th centuries. contributed by Russian scientists: I.M. Sechenov, N.E. Vvedensky, I.P. Pavlov, K.A. Timiryazev.

Genetics emerged as an independent biological science that studies the heredity and variability of living organisms. It also followed from Mendel’s works that there are material units of heredity, later called genes. This discovery of Mendel was appreciated only at the beginning of the 20th century. as a result of research by H. de Vries in Holland, E. Chermak in Austria, K. Correns in Germany. American scientist T. Morgan, studying the giant chromosomes of the Drosophila fly, came to the conclusion that genes are located in cell nuclei, in chromosomes. He and other scientists developed the chromosomal theory of heredity. Thus, genetics was largely combined with cytology (cytogenetics) and the biological meaning of mitosis and meiosis became clear.

At the turn of the 19th and 20th centuries. Professor of Moscow University A.A. Kolli raised the question of the molecular mechanism of inheritance of traits. The answer to the question was given in 1927 by the Soviet scientist N.K. Koltsov, putting forward the matrix principle of coding genetic information (see Transcription, Translation).

The matrix coding principle was developed by the Soviet scientist N.V. Timofeev-Resovsky and the American scientist M. Delbrück.

Significant successes have been achieved in the sciences that study the individual development of organisms - ontogenesis. In particular, methods of artificial parthenogenesis were developed.

Ethology, which studies animal behavior, has become an independent biological science.

Soviet scientist N.I. Vavilov, based on the achievements of evolutionary theory and genetics and as a result of his own many years of research, created the theory of centers of origin of cultivated plants. A.I. Oparin extended evolutionary ideas to the “pre-biological” period of the Earth’s existence and put forward a theory of the origin of life.

Zoologists and botanists in the 20th century. continued studying the life of animals and plants in different conditions a habitat. Great progress has been made in the study of certain groups of animals and plants - ornithology (birds), entomology (insects), herpetology (reptiles), algology (algae), lichenology (lichens), etc. An outstanding contribution to the development of zoology was made by Soviet scientists M.A. Menzbier, S. I. Ognev, A. N. Formozov, V. A. Dogel, L. A. Zenkevich, K. I. Scriabin, M. S. Gilyarov and others; botany - M. I. Golenkin, K. I. Meyer, A. A. Uranov, L. I. Kursanov, V. L. Komarov and others.

Animal physiology developed under the strong influence of the works of Soviet scientists I. P. Pavlov, L. A. Orbeli, A. A. Ukhtomsky, A. F. Samoilov, the English scientist C. Sherrington and many others.

The main attention was paid to the physiology of the central nervous system, mechanisms of signal transmission along the nerve and from nerve to muscle.

As a result of studying the regulation of the formation, growth and development of animals, endocrinology, the science of hormones, which is important for medicine, became a separate biological discipline.

The Soviet scientist M. M. Zavadovsky put forward the concept of interaction between endocrine organs based on the principle of feedback (see Endocrine system).

Plant physiology has made progress in understanding the nature of photosynthesis, studying the pigments involved in it, and above all chlorophyll.

With the entry of man into outer space, a new science appeared - space biology. Its main task is to provide life support for people during space flight, to create artificial closed biocenoses on spaceships and stations, to search for possible manifestations of life on other planets, as well as suitable conditions for its existence.

In the 70s A new branch of molecular biology has emerged - genetic engineering, the task of which is the active and purposeful restructuring of the genes of living beings, their design, i.e. control of heredity. As a result of this work, it became possible to introduce genes taken from one organism or even artificially synthesized into the cells of other organisms (for example, the introduction of a gene encoding the synthesis of insulin in animals into bacterial cells). Hybridization of cells of different types has become possible - cell engineering. Methods have been developed that make it possible to grow organisms from individual cells and tissues (see Cell and Tissue Culture). This opens up enormous prospects for the reproduction of copies - clones of valuable individuals.

All these achievements are of extremely important practical importance - they have become the basis of a new branch of production - biotechnology. The biosynthesis of drugs, hormones, vitamins, and antibiotics is already being carried out on an industrial scale. And in the future, in this way we will be able to obtain the main components of food - carbohydrates, proteins, lipids. The use of solar energy based on the principle of plant photosynthesis in bioengineering systems will solve the problem of providing energy to the basic needs of people.

The importance of biology today has increased immeasurably in connection with the problem of preserving the biosphere due to the rapid development of industry, agriculture, and the growth of the Earth's population.

An important practical direction of biological research has emerged - the study of the human environment in a broad sense and the organization on this basis of rational methods of managing the national economy and nature conservation.

Another important practical significance of biological research is its use in medicine. It was the successes and discoveries in biology that determined the modern level of medical science. Further progress in medicine is also associated with them. You will read about many tasks of biology related to human health in our book (see Immunity, Bacteriophage, Heredity, etc.).

Biology today is becoming a real productive force. By the level of biological research one can judge the material and technical development of society.

The accumulation of knowledge in new and classical areas of biology is facilitated by the use of new methods and instruments, for example, the advent of electron microscopy.

In our country, the number of biological research institutes, biological stations, as well as nature reserves and national parks, which play an important role as “natural laboratories,” is growing.

A large number of biologists of various specialties are trained in higher educational institutions (see Biological education in the USSR). Many of you will in the future join a large team of specialists who are faced with the task of solving important biological problems.