The human body is a complex biological system. All organs of the human body are interconnected, are in constant interaction and together, are a single self-regulating and self-developing system. The activity of the organism as a whole includes the interaction of the human psyche, its motor and vegetative functions with various environmental conditions.

Physical exercises have a significant impact on the formation of the skeleton (curvature of the spine is corrected, posture improves). Metabolic processes increase, in particular, calcium metabolism, the content of which determines the strength of bones. The skeleton, performing supporting and protective (skull, chest, pelvic bones, etc.) functions, is extremely durable. Individual bones can withstand loads up to 2 tons. Continuous (bones of the skull, etc.) and articular connections of bones make it possible to compose separate blocks, kinematic systems with a large degree of freedom, enabling the links of such systems to move along complex trajectories.

A complex set of interconnected reactions of splitting (dissimilation) and synthesis (assimilation) of organic substances is the basis for the development of the human body.

The human body develops under the influence of the genotype (heredity), as well as factors of the constantly changing external natural and social environment.

Without knowing the structure of the human body, the features of life processes in its individual organs, organ systems and in the whole organism, it is impossible to educate, educate and treat a person, as well as ensure his physical improvement.

Knowing oneself is an important step in solving the problem of the formation of physical culture of the personality of a future specialist, who, when studying this topic, should:

♦ to study the features of the functioning of the human body and its individual systems under the influence of physical exercises and sports in various environmental conditions;

♦ to be able to diagnose the state of one's body and its individual systems, to make the necessary correction in their development by means of physical culture and sports;

♦ be able to rationally adapt physical culture and sports activities to the individual characteristics of the body, working conditions, life, recreation and differentiate the use of physical culture and sports means, taking into account the noted features.

There are over 100 trillion in the human body. (1x10 14) cells. Each cell is at the same time a factory for the processing of substances entering the body; a power plant that generates bioelectric energy; a computer with a large amount of storage and issuance of information. In addition, certain groups of cells perform specific functions inherent only to them (muscles, blood, nervous system, etc.).

The most complex structure is the cells of the central nervous system (CNS) - neurons. There are more than 20 billion of them in the body. Each neuron contains about a thousand enzymes. All neurons of the brain can accumulate over 10 billion units of information in 1 second, i.e. several times more than the most advanced computer system.

The external activity of a person and the internal processes occurring in the body are carried out according to the mechanism of a reflex controlled from the central nervous system.

Each cell, group of cells, organ operate in two modes: excitation (active state) and inhibition (cessation of the active state and recovery). Excitation and inhibition are two opposite processes, the interaction of which ensures the coordinated activity of the nervous system, the coordinated work of the body's organs, the regulation and improvement of the functions of the whole organism.

Movement is the most important property of the human body. Due to the presence of skeletal muscles, a person can move around, perform movements with individual parts of the body. Constant movements also occur in the internal organs, which also have muscle tissue in the form of special “smooth” muscles (intestinal peristalsis, maintaining the tone of arterial blood vessels, etc.). The heart muscle has a complex structure, which continuously, throughout a person’s life, works as a pump, ensuring the movement of blood through the blood vessels.

During the evolutionary development of man in onto- and phylogenesis, motor activity had a significant impact on the morphogenesis of individual organs and systems of the body.

The human body consists of individual organs that perform their own functions. There are groups of organs that perform jointly common functions - organ systems. In their functional activity, organ systems are interconnected.

Many functional systems largely provide human motor activity. These include the circulatory system, respiratory system, musculoskeletal and digestive systems, as well as excretory organs, endocrine glands, sensory systems, nervous system, etc.

Medical science considers the human body in unity with external nature and the social environment.

The external environment in general can be represented by a model consisting of three interacting elements: the physical environment (atmosphere, water, soil, solar energy); biological environment (animal and plant world); social environment (man and human society).

The influence of the external environment on the human body is very multifaceted. The external natural environment and the social environment can have both beneficial and harmful effects on the body. From the external environment, the body receives all the substances necessary for life and development, at the same time it receives a numerous flow of irritations (temperature, humidity, solar radiation, industrial, professionally harmful effects, etc.), which tends to disrupt the constancy of the internal environment of the body.

The normal existence of a person in these conditions is possible only if the body responds in a timely manner to the effects of the external environment with appropriate adaptive reactions and maintains the constancy of its internal environment.

Environmental problems have a direct or indirect impact on the physical and moral condition of a person.

In the modern world, the problems of ecology - the interaction of the body with the environment - have become seriously aggravated.

According to the World Health Organization, 80% of human diseases are caused by environmental degradation.

A distinctive feature of a person is that he can consciously and actively change both external and social conditions in order to improve health, increase working capacity and prolong life. Undoubtedly, the relationship of society with the environment must be brought under stricter control.

By a corresponding change in external conditions, a person can also affect his own state of health, physical development, physical fitness, mental and physical performance.

Physical training has a versatile effect on mental functions, ensuring their activity and stability.

There are the results of numerous studies on the study of the stability of attention, perception, memory, the ability to verbally count of varying complexity, and other aspects of thinking in trained and untrained individuals. The stability of the studied parameters was assessed by the level of their preservation under the influence of varying degrees of fatigue, as well as by the ability to maintain working capacity at the exact time. It was established that the stability of the parameters of mental activity was directly dependent on the level of versatile physical fitness.

Mental performance deteriorates to a lesser extent under the influence of adverse factors, if, under these conditions, physical exercises are applied appropriately. Optimal physical fitness ensures the preservation of a number of indicators of higher nervous activity, in particular, the stability of the functions of the second signaling system.

Fatigue is a condition that occurs as a result of work with insufficient recovery processes and manifests itself in a decrease in working capacity, a violation of the coordination of regulatory mechanisms and a feeling of fatigue. Fatigue plays an important biological role, serves as a warning signal of a possible overstrain of the working organ or the organism as a whole.

There are two phases of fatigue development: compensated and uncompensated. In the compensated phase, there is no visible decrease in performance. The work is carried out by connecting to the intense activity of other body systems, which before the onset of fatigue did not take an active part in this work.

The impossibility of maintaining the required intensity of work even when the reserve systems of the body are connected means the beginning of an uncompensated phase of fatigue.

When working at a significant intensity that does not correspond to the level of immediate readiness of the body to perform a given load, acute fatigue occurs.

The summation of shifts in the neuromuscular and central nervous system that occur during repeated tedious work causes chronic fatigue.

Systematic continuation of work in a state of fatigue, improper organization of work, physical training, prolonged work associated with excessive mental or physical stress - all this can lead to overwork.

Acute and chronic fatigue, as well as overwork, can lead to diseases of the nervous system, exacerbation of cardiovascular diseases, hypertension and peptic ulcers, and a decrease in body strength. For example, under the influence of long-term (chronic) examination emotional stress, most of the examined students showed significant changes in the intensity of blood filling of blood vessels and the reactivity of brain biopotentials, electrocardiographic and biochemical parameters that did not return to normal within 2-3 days after the exams.

Thus, university students experience prolonged emotional stress twice a year, which is a risk factor.

Mental overwork borders on the disease and has a longer recovery period. It is a consequence of the fact that the human brain, having great compensatory capabilities, is able to work with overload for a long time, without letting us know about our fatigue, which we feel only when the phase of overwork has begun.

The means of restoring the body after fatigue and overwork are: optimal, physical activity, switching to other types of work and combining work with outdoor activities, rational nutrition, establishing a strict hygienic lifestyle. Sufficient in time and full sleep, water procedures, steam bath, massage and self-massage, pharmacological agents and physiotherapy procedures, psychoregulatory training accelerate the recovery process.

The rhythmic flow of physiological processes is an important property of a living organism. Everything in the body - every organ, cell, blood composition, hormones, body temperature, heart rate (HR), blood pressure, respiration and other systems, and indicators of their functions - has its own rhythms, measured in seconds, hours, months and even years.

The biorhythms of individual organs and systems interact with each other and form an ordered system of rhythmic processes - the organization of the body's activity in time. For example, a daily biorhythm is distinguished, in which a high level of performance in a person is observed from about 8.00 to 12.00 and from 17.00 to 19.00. During these hours, almost all body functions are activated. Significantly reduced psychophysical functions in the periods from 2 to 3 am and from 13.00 to 15.00 hours of the day.

With the manifestation of efficiency, the most productive are Tuesday, Thursday and Friday, and the ineffective ones are Monday and Saturday.

A properly drawn up daily routine, the distribution of work in such a way that the greatest load corresponds to the greatest capabilities of the body, is one of the most important tasks of maintaining health and working capacity.

Violation of biorhythms, the regime of the working day, work, training, nutrition, rest, sleep, physical activity can lead not only to a decrease in working capacity, but also to the development of the disease.

Insufficient motor activity creates special unnatural conditions for human life, negatively affects the structure and functions of all tissues of the human body. Under these conditions, the development of the younger generation is delayed and the aging of the elderly is accelerated.

In the absence of a sufficient dose of daily muscle movements, unwanted and significant changes in the functional state of the brain and sensory systems occur. As a result, there is a decrease in the overall defenses of the body, an increase in the risk of various diseases.

This condition is characterized by increased extreme instability of mood, weakening of self-control, impatience, sleep disturbance, loss of ability for prolonged work or physical exertion. All these symptoms can manifest themselves in varying degrees.

The most effective alternative to hypokinesia and hypodynamia in modern conditions can be physical exercises.

The progress of science and technology has made it necessary for a person to obtain a significant amount of professional knowledge and a large amount of various information. The pace of life has increased immeasurably. All this led to the presentation of high demands on the modern person to his physical condition and significantly increased the load on the mental, mental and emotional spheres.

In connection with the activation of educational work with increasing loads, it is required to improve the conditions and regime of study, life and rest of students using the means of physical culture. The means of physical culture are physical exercises, the healing forces of nature (the sun, air and water) and hygienic factors (sanitary and hygienic conditions, rest, sleep, nutrition).

The use of the healing forces of nature (hardening) strengthens and activates the body's defenses, stimulates metabolism, the activity of the heart and blood vessels, and has a beneficial effect on the state of the nervous system.

Systematic physical training, physical exercises in the conditions of intense educational activity of students are important as a way to relieve nervous tension and maintain mental health. Discharging increased nervous activity through movement is most effective.

The role of exercise is not limited to the beneficial effects on health. Observation of people who regularly exercise has shown that systematic muscular activity increases the mental, mental and emotional stability of the body during prolonged intense mental or physical work.

A person who leads a mobile lifestyle and systematically engages in physical exercises can do much more work than a person who leads a sedentary lifestyle. This is due to the reserve capacity of the body.

The activation of the physiological functions of the body during muscular activity should be considered as the mobilization of reserves. At the same time, a trained organism has large reserves and can use them more fully than an untrained one.

Each organ, organ system and the body as a whole, under the influence of directed physical training, significantly increase the indicators of working capacity, physical reserve.

The metabolism and energy in the human body is characterized by complex biochemical reactions. Nutrients (proteins, fats and carbohydrates) that enter the internal environment of the body with food are broken down in the digestive tract. The cleavage products are carried by the blood to the cells and absorbed by them. Oxygen, penetrating from the air through the lungs into the blood, takes part in the oxidation process that occurs in the cells.

Substances formed as a result of biochemical metabolic reactions (carbon dioxide, water, urea, etc.) are excreted from the body through the lungs, kidneys, and skin.

Metabolism is a source of energy for all vital processes and body functions. When complex organic substances are broken down, the potential chemical energy contained in them is converted into other types of energy (bioelectric, mechanical, thermal, etc.).

The intensity of the metabolic process in the human body is very high. Every second, a huge number of molecules of various substances are destroyed, and at the same time new substances necessary for the body are formed. In 3 months, half of all tissues of the human body are updated.

The growth of hair, nails, peeling of the skin - all this is the result of the metabolic process. For 5 years of study, the cornea of ​​the eye of a student is replaced 250 times, and the stomach tissue is updated 500 times.

To maintain energy balance, maintain normal body weight, ensure high mental and physical performance and prevent diseases, it is necessary, with sufficient and nutritious nutrition, to increase energy consumption by increasing physical activity, for example, through regular physical exercises.

Muscular activity. Physical exercise or sports increase the activity of metabolic processes, train and maintain at a high level the mechanisms that carry out the metabolism and energy in the body.

1.13. (addition) Universal properties of biosystems

Despite the specificity of biosystems of different levels, a number of universal properties can be distinguished for them. Let's name some of them.

Certain composition and orderliness. All biosystems are characterized by high orderliness, which can be maintained only due to the processes taking place in them. The composition of all biosystems that lie above the molecular level includes certain organic substances, some inorganic compounds, as well as a large amount of water. The orderliness of the cell is manifested in the fact that it is characterized by a certain set of cellular components, and the orderliness of the biogeocenosis is that it includes certain functional groups of organisms and the inanimate environment associated with them.

Hierarchy of the organization. As discussed in paragraph 1.05, life manifests itself simultaneously at many levels of organization, each of which has its own characteristics.

Metabolism- the most important feature of the functioning of biosystems. This is a set of chemical transformations and movements of substances occurring in them. At the cellular and organismal levels, metabolism is associated with food, gas exchange and highlighting, and, for example, on the biogeocenotic - with the circulation of substances and them moving between different biogeocenoses.

Energy flow through biosystems is closely related to their metabolism. Due to the fact that the atoms of matter do not change during their transformations, matter can cycle in living systems. Energy, in accordance with the second law of thermodynamics, is partially dissipated during transformations (turns into the form of heat), and therefore living systems exist only under conditions of an energy flow flowing through them from an external source. For the biosphere as a whole, such a source is the Sun.

Ability to develop. All biosystems arise and improve in the course of evolution. Evolution at the molecular level has led to the emergence of organisms; due to the evolution of populations, the characteristic properties of organisms and all their constituent systems change. Changes in biogeocenoses and the biosphere are also associated with their ability to evolve. The development of an individual organism is called ontogeny; evolutionary history of the species phylogenesis; development of biocenoses in one area - succession.

Fitness- correspondence between the characteristics of biosystems and the properties of the environment with which they interact. Fitness cannot be achieved once and for all, since the environment is constantly changing (including due to the impact of biosystems and their evolution). Therefore, all living systems are able to respond to environmental changes and develop adaptations to many of them. The result of the ability of living systems to develop adaptations is the amazing perfection and expediency of living organisms and life in general. Long-term adaptations of biosystems are carried out due to their evolution. Short-term adaptations of cells and organisms are provided due to their irritability- the ability to respond to external or internal influences. Biosystems of all other levels also respond in a certain way to changes, which allows us to say that they are in a state of exchange of information with the environment.

Self-regulation. Biosystems are in a state of constant exchange of matter, energy and information with the environment. For example, cells and organisms, thanks to self-regulation, maintain the constancy of their internal environment (homeostasis), and biogeocenoses maintain their species composition and certain properties of the inanimate environment. Maintaining the constancy of the properties of biosystems is ensured by negative feedback, and their change and development - by positive feedback.

Dynamism(a state of continuous change). Vital activity at all levels of organization of biosystems is associated with the exchange of substances and information, as well as the flow of energy. Moreover, each biosystem, starting from the cellular level, is not so much a structure as a process. Thus, the cell remains itself, despite the fact that as a result of metabolism, the substances that form it are replaced. The population exists, despite the fact that the individuals that make up it die and appear. For cells and organisms, a characteristic manifestation of dynamism is mobility - the ability to change the position and shape of the system itself and its parts.

Integrity(integration) is a necessary condition for considering an object as a system. This is the result of the interconnection and interdependence of parts of biosystems, the basis for the emergence of emergent properties in a system. Systems of different levels differ in the degree of interdependence of their parts. For example, the composition of a cell must include a completely specific composition of components that strictly correspond to each other (if the mitochondria does not synthesize all of its proteins, then the nucleus must necessarily control the synthesis of the missing ones, and quite corresponding to those present in the mitochondria). The body is made up of a set of organs. Biogeocenosis also consists of a certain set of components (for example, autotrophs and heterotrophs), but their composition turns out to be largely replaceable. Since the connections of subsystems in a cell and an organism are more rigid (the properties of one subsystem require strictly defined characteristics of another subsystem) than in a biogeocenosis, the cell and the organism can be considered more integral. At the biogeocenotic and biospheric levels, biosystems include both living and non-living components (however, non-living components, such as dead tissues, can also be part of organisms, as well as biosystems of other levels).

Uniqueness. All biosystems, starting from the cellular level, are unique and differ from similar systems. For example, organisms that have identical hereditary information (identical twins, clones, etc.) have a unique individuality that depends on infinitely diverse features of the influence of the environment on them and self-regulation in the course of development.

Ability to reproduce biosystems ensures the stability of life in time. Biomolecules are synthesized by the cell; cells (and even some eukaryotic cell structures) reproduce by dividing. At the organismal level, reproduction is ensured by reproduction. The continuity of generations at the organismal (as well as at the cellular) level is ensured heredity, and the possibility of evolution - variability. The reproduction of populations, biogeocenoses (and perhaps the biosphere) is ensured not only by the reproduction of organisms, but also due to their ability to settle.

All organisms are made up of cells. At the same time, the cells themselves turn out to be special biosystems that have special properties and exist according to their own specific laws.

It is noteworthy that a number of properties of the cell, as a unit of a special level of organization of living matter, arose through the merging and interaction of the properties of the previous one - the molecular level.

All components of the cell are formed from various molecules, and all biochemical reactions between the molecules of simple and complex chemical compounds take place in the cell. Therefore, many properties of a cell depend on the molecular level - the composition of its components and their role in the cell. For example, DNA molecules carry the genetic code that determines the control of synthesis processes in the cell.

However, the next higher level of organization of living matter (organismal level) also affects the properties of the biosystem at the cellular level. For example, cells have properties that are determined by the performance of certain functions in the body: the cells of the nervous tissue differ in structure and properties from the cells of the excretory or integumentary tissue.

The examples show that the properties of one structural level of life affect the systems of a higher level, but they themselves depend on it. However, both are manifested in some properties of the level, but do not fully reflect them, since each level has its own special properties. If at the molecular level it is possible to consider the process of DNA synthesis, replication, then at the cellular level the significance of these processes is manifested in the life of the cell.

• metabolism of substances (metabolism);
• absorption and, consequently, the inclusion of various chemical elements of the Earth in the content of my living;
• transfer of hereditary information from cell to cell;
• accumulation of changes in the genetic apparatus as a result of interaction with the environment;
• response to irritation when interacting with the external environment.

Thus, the cell, having appeared in the process of evolution billions of years ago, acquired the character of a biosystem representing life. Over the next many millions of years, the cell not only became more complex, but also, having created specialized tissues, turned out to be able to live and actively function as part of multicellular organisms, remaining the main structural unit of life. The cells of a multicellular organism, like a free-living cell, reproduce, transfer their hereditary (genetic) information in this process, replace dead cells in the tissues with new ones, and thereby ensure the longevity of the organism.

Questions about this item:

due to different diets.

Two piglets of the same litter became dissimilar

The whole range of possible changes in a given genotype under different developmental conditions is called the reaction norm. Thus, we can say that it is not the trait that is inherited, but the norm of the genotype reaction.

Non-hereditary (paratypic modification) phenotypic changes are the reaction of a particular genotype to different environmental conditions. Under different environmental conditions, the same genotype will be expressed by different phenotypes.

biological system(in psychophysiology) - a set of functionally related elements or processes combined into a whole to achieve a biologically significant result. The most complete content of B. s. is revealed in the principles of a functional system (P.K. Anokhin). The main property of B. with. - Obtaining a useful adaptive result. B. s. refers to dynamic systems. One and the same biological object can act both as an integral system and as a subordinate one. B. s. has a number of properties: 1) the result as a system-forming factor; 2) the presence of connections and relationships (considerable attention is paid to backbone connections); 3) existence of structure and organization; 4) hierarchy of links; 5) self-regulation; 6) sustainability; 7) emergence (the system has a property or properties that its components do not have); 8) multiparametric regulation, etc.

An essential feature of B. with. is the hierarchy of its structure, connections, organization, management, etc. B. s. is a complex dynamic system. A biological object can simultaneously act as an integral system, and as a subsystem of a higher level. For example, the respiratory system as a self-regulating homeostatic system for regulating the exchange of gases in the body is at the same time a subsystem in the system of the whole organism, the latter is a subsystem of the population biosystem, etc. A system of a higher rank subordinates systems of a lower rank to its laws. Hierarchy of the structure, connections, organization of management of B. s. - the result of a long evolutionary development of organisms. According to the theory of functional systems (P.K. Anokhin), the interaction between B. s. of different rank is carried out through the result (principle of the hierarchy of results). The result of the activity of the lower hierarchical B. s. is included as a component in the result of the activity of a higher hierarchical B. s.

In contrast to the classical sciences, which relied in their constructions mainly on substratum concepts (weight, mass, etc.), in the system approach, conceptual concepts are based on qualitatively different concepts - "correlation", "organization", "management", etc. connections in B. with. leads to the concept of "structure" and "organization" that ensure the orderliness of B. s. The system approach directs the attention first of all to identification in the whole of the organization B. of page. through the study of its connections, relationships and management. The development of the concept of "organization" makes it necessary to introduce such concepts as "management", "goal setting", "result", etc. The concept of "organization" is most fully disclosed in the principles of a functional system

Fundamental properties of living systems.

All levels of organization of living systems are characterized by properties that distinguish living matter from non-living matter. The main, fundamental properties of living things include:

1. Consumption from the environment and conversion of nutrients (subsystems) with low entropy (metabolism ). This is necessary to maintain the structural integrity of the biosystem, its growth and reproduction.

2. Exchange of matter and energy with the environment. In this way, the influx of the structural elements of living matter necessary for life, their transformation, utilization, and the release of products with high entropy and thermal energy are ensured.

3. Regulation . Maintaining the structural and functional organization of a biological system requires the orderliness of the flow of metabolic processes. To do this, highly organized organisms form special regulatory mechanisms that modulate the activity of individual organs and systems, the intensity of the processes occurring in them. The mechanisms of regulation ensure the adaptation of the system to changing environmental conditions.

4. Irritability and reactivity . Various chemical and physical environmental factors are a kind of signals or sources of information to which a living organism reacts in one form or another. Structures intended for the perception and processing of relevant information use the incoming irritation, which allows the body to adequately respond to it.

5. Reproduction . This property ensures the maintenance or increase in the number of biological objects of all kinds and types. Reproduction is based on the process of cell division. In the course of cell division, the transfer of DNA (genetic material) of mother cells to daughter cells is carried out, and due to this, subsequent reproduction of all other components of the living is ensured. The preservation of information about the properties of previous generations, encrypted in DNA molecules (genes), transmitted from generation to generation is the essence of heredity.

6. Homeostasis. This is self-renewal and self-maintenance of the internal environment of the body.

7. Heredity is the ability of organisms to transmit their characteristics, properties and developmental features from generation to generation.

8. Variability - this is the ability of organisms to acquire new signs and properties; it is based on changes in biological matrices - DNA molecules.

9. Growth and development . Growth- a process that results in a change in the size of an organism (due to the growth and division of cells). Development- a process that results in a qualitative change in the body. Under development living nature - evolutions understand the irreversible, directed, regular change of objects of living nature, which is accompanied by the acquisition of adaptation (adaptations), the emergence of new species and the extinction of pre-existing forms. The development of a living form of the existence of matter is represented by individual development, or ontogeny, and historical development, or phylogenesis.

10. Fitness. This is the correspondence between the characteristics of biosystems and the properties of the environment with which they interact. Fitness cannot be achieved once and for all, since the environment is constantly changing (including due to the impact of biosystems and their evolution). Therefore, all living systems are able to respond to changes in the environment and develop adaptations to many of them. The result of the ability of living systems to develop adaptations is the amazing perfection and expediency of living organisms and life in general. Long-term adaptations of biosystems are due to their evolution. Short-term adaptations of cells and organisms are provided due to their irritability.

11. Discretion (dividing into parts). A separate organism or other biological system (species, biocenosis, etc.) consists of separate isolated, i.e., isolated or delimited in space, but, nevertheless, connected and interacting with each other, forming a structural and functional unity. Cells consist of individual organelles, tissues - from cells, organs - from tissues, etc. This property allows the replacement of a part without stopping the functioning of the whole system and the possibility of specializing different parts for different functions.

12 . Integrity(integration) is a necessary condition for considering an object as a system. This is the result of the interconnection and interdependence of parts of biosystems, the basis for the emergence of emergent properties in a system. Systems of different levels differ in the degree of interdependence of their parts. So, a cell and an organism are relatively more integral biosystems than a biogeocenosis. This is manifested in the fact that the composition of the parts of the cell and the body is less variable than the composition of the biogeocenosis. At the biogeocenotic and biospheric levels, biosystems include both living and non-living components (moreover, non-living components, such as dead tissues, can be re-integrated

The fundamental properties of living things are closely related, inseparable phenomena. Nevertheless, the primary effects of highly toxic compounds are sometimes associated with a selective violation of certain fundamental properties of living things - metabolism, plastic metabolism, energy metabolism, regulation, irritability, reproduction, homeostasis. The more toxic the compound, the more pronounced this selectivity.

Substances necessary for the body: - enzymes (biological catalysts, regulate metabolic processes); - vitamins (necessary for all living organisms for metabolism); - hormones (coordinators of metabolism).

Haeckel's biogenetic law - each organism during the period of embryonic development repeats the stages that its species had to go through in the process of evolution. That is, as an individual passes through the stages of the embryo and early fetus, his body repeats or re-passes the evolutionary history of its species. For example, a human embryo in nine months spent in the uterus goes through many stages - from invertebrate to fish, then to amphibian, to reptile, to mammal, to primate, to the likeness of hominids and to man as such. The universality of this law has been refuted by modern biologists.

Introduction

Ecology is currently called the science of a person's "own home" - the biosphere, its features, interaction and relationship with a person, and a person with the whole human society. Ecology is not only an integrated discipline, where physical and biological phenomena are connected, it forms a kind of bridge between natural and social sciences.

The main purpose of the test is to study the subject of ecology.

For this you need:

• - to reveal the concept of the Earth's biosystem and the stages of its development, to reveal the organization of biosystems and their properties;
• - consider the characteristics of species related to the r-model of population dynamics;
• - define environmental pollution, reveal the main types and types of pollution, their sources and the degree of impact on the environment;
• - to study the sanitary and hygienic regulation of the environment, to reveal the basic principles of sanitary and hygienic regulation, as well as the shortcomings of the system of sanitary and hygienic regulation.

Biosystems of the Earth, steps of the hierarchy of biosystems

Biosystems are biological systems in which biotic components of different levels of organization interact in an orderly manner with the surrounding physical environment, i.e. with abiotic components (energy and matter), constituting a single whole. There are seven main levels: - molecular; - cellular; - tissue; - organism; - population-species; biogeocenotic; - biospheric. The hierarchical organization of biosystems illustrates the continuity and discreteness of the evolution of life. Development is a continuous process, but also discrete, since changes pass through a number of separate levels of the organization. The division of the hierarchy into steps is conditional, because each level is integrated, i.e. associated with neighboring levels in a functional sense. For example, genes cannot function in nature outside a cell, multicellular cells - outside organs, organs - outside an organism, etc. A community cannot exist if there is no circulation of substances in it and no energy comes from outside. An ecosystem is not viable without interconnection with population systems and the biosphere as a whole. For the same reasons, human civilization cannot exist outside the natural world. Biosystems of different levels are the subject of study of various disciplines. Systems that are located above the level of organisms, i.e. population systems, ecosystems and the biosphere, studies ecology.

The most important consequence of the hierarchical organization of living nature is that, as subsystems combine into larger functional units, these new systems acquire unique properties that did not exist at the previous level. In ecology, these qualitatively new properties are called emergent (eng. Unexpectedly appearing). They cannot be predicted based on the properties of the lower order subsystems that make up the system of a higher level of organization. Thus, the essence of the emergence principle is that biological systems have properties that cannot be reduced to the sum of the properties of their constituent subsystems.

In ecology, the organism is considered as an integral system interacting with the external environment, both abiotic and biotic. In this case, our field of vision includes such a set as a biological species, consisting of initial individuals, which, however, as individuals differ from each other. But all of them are united by a single gene pool for all, which ensures their ability to reproduce within the species. Since each individual has its own specific characteristics, their attitude to the state of the environment, to the impact of its factors is different. For example, some individuals may not be able to withstand a rise in temperature and die, but the population of the entire species survives at the expense of others who are more adapted.

A population is a complex genetic system. Each population is characterized by a certain number of individuals, the ratio of males, females and individuals of different age groups (newborns, young, adults, old), the frequency of variations of different characters. For example, in the northern populations of one species - the agile lizard, all males are brown, in the southern - green, and in the middle lane you can meet both brown and green in the same population. Hundreds and thousands of generations - the usual time of existence of individual populations. Sometimes there are small groups of individuals that exist for 2-3 generations, but these are not real populations. Neither an individual, nor even a small group of individuals like a family, can exist in the process of evolution for a long time. A population is the smallest group of individuals that has its own evolutionary destiny. Any population is characterized by fluctuations in the number of its constituent individuals. There are many reasons for this: abundance or lack of food, climate change, enemies, etc.

Biocenosis is a set of plants, animals, fungi and microorganisms that jointly inhabit a plot of the earth's surface and are characterized by certain relationships both with each other and with a combination of abiotic factors. The components of the biocenosis are phytocenosis (a set of plants), zoocenosis (a set of animals), mycocenosis (a set of fungi) and microbiocenosis (a set of microorganisms). A synonym for biocenosis is a community.

A plot of the earth's surface (land or water body) with the same type of abiotic conditions (relief, climate, soils, the nature of moisture, etc.), occupied by one or another biocenosis, is called a biotope (from the Greek topos - place). In spatial terms, the biotope corresponds to the biocenosis. The biotope, with which the organisms living here and the conditions for their existence, are associated, undergoes changes from the side of the biocenosis. The homogeneity of the climatic conditions of the biocenosis determines the climatotope, soil-ground - edaphotop, moisture - hydrotope.

Biotope and biocenosis are components of an ecosystem - a natural complex formed by living organisms (biocenosis) and their habitat (biotope), which are interconnected by metabolism and energy. An ecosystem does not have a strict taxonomic definition, and it can be objects of varying complexity and dimensions - from a hummock to a mainland, from a small reservoir to the World Ocean. At the same time, the ecosystem is the main functional and structural natural system of the biosphere, since it is made up of interdependent organisms and an abiotic environment that support life in the form in which it exists on Earth. Each biocenosis is a system that includes many ecologically and biologically different species that have arisen as a result of selection and are able to exist together in specific natural conditions. The species composition of a biocenosis is a systematized set of species of plants, animals, fungi and microorganisms characteristic of a given biocenosis. The species composition of the phytocenosis is more or less constant compared to the zoocenosis, as the animals move around. Accounting for fungi and microorganisms due to excessive species abundance or their microscopic size is difficult. The biocenoses of humid tropical forests are distinguished by the greatest species diversity, and the polar ice deserts are the least diverse.

Among the terrestrial biocenoses, flowering plants are rich in this regard, the species saturation of mushrooms, insects is somewhat less, and even less - birds, mammals and other representatives of the fauna. In the tundra, mosses and lichens have the highest species diversity. The larger the territory occupied by the biocenosis and the more favorable the environmental conditions, the greater the species composition. With a large species composition, we are talking about floristic and faunal richness. The species that prevail in the biocenosis are called dominants. Distinguish between permanent and temporary dominants. The latter dominate only for a short period of vegetation, being replaced by others, also temporary dominants. Moreover, the dominants of the upper tier are of greater ecological importance than the lower ones. In the tier there may be another species that has an important, but less than dominant, value - a subdominant. Thus, in a birch-blueberry pine forest, birch is a subdominant if it forms a tree layer together with pine. Secondary species (assectators) are part of various tiers. In the biocenosis, one can also meet anthropophyte plants that have penetrated into the phytocenosis as a result of a conscious or accidental introduction by a person. Dominants that determine the nature and structure of the biocenosis are called edificators (builders). Basically, these are those plants that create the internal biotic environment of the community: in a pine forest - pine, oak - oak, feather grass steppe - feather grass, etc. As a rule, subdominants are subadifiers.

The biocenosis is characterized by a vertical and horizontal structure. The vertical structure of the biocenosis is reflected in tiering - the vertical division of the community of organisms into sufficiently, clearly limited horizons of activity. Layering in the first approximation is related to the habitat of organisms. So, it is possible to distinguish species that live in the air, hydrosphere, lithosphere, soil environment and at the boundary of media. In this case, layering is a manifestation of the vertical division of the biosphere into its structural spheres. The underground layering of the biocenosis reflects the vertical distribution of the root systems of phytocenosis plants. The presence of underground layering of phytocenosis ensures the most productive use of soil moisture: plants of different hydroecological groups grow in the same habitat - from xerophytes to hygrophytes. The layering of the phytocenosis is of great ecological importance. It is the result of a long and complex process of interspecific competition and mutual adaptation of plants to each other. Thanks to it, the phytocenosis forms species that are very different in their ecology and have different life forms (tree, shrub, grass, moss, etc.). The horizontal structure of the biocenosis is reflected in synusia (from the Greek synusia - cohabitation, community) - parts of the phytocenosis spatially and ecologically separated from each other, consisting of plant species of one or more ecologically close life forms. If the tier is a morphological concept, then synusia is an ecological one. It may coincide with the tier and may be only part of it. The dismemberment of the tree layer into synusia can be observed if you rise high above the forest in autumn: dark coniferous spruces and light coniferous pines are replaced by yellowed birches, reddish aspens and brown oaks. In addition, the synusia reflects a mosaic of ecological factors in the formation of a plant community: pine occupied dry sandy soils, spruce occupied more humid sandy and loamy soils, birch and aspen occupied clearings, and oak occupied the most fertile soils.

They can be permanent (sessile) or temporary (vagile).

In general, the community is characterized by daily, seasonal (annual) and long-term dynamics, which are characteristic of both plants and animals. The daily cycle, caused by the change of light and dark parts of the day, in plants is manifested in the intensity of photosynthesis, respiration, opening and closing of flowers, in animals - in different daily activities (day, twilight and night).

The seasonal dynamics of the biocenosis depends on the phenological state of the phytocenosis, the species composition and the number of animals living in it. Each type of plant organisms during the growing season goes through certain stages of development (the beginning of the growing season, flowering, fruiting and dying off). In a phytocenosis consisting of many species, the phases of plant development may or may not coincide.

The seasonal dynamics of animal representatives of the biocenosis is associated with their reproduction, vital activity and migration. The spring arrival and autumn departure of birds, fish spawning, the appearance of young animals, the activity of pollinating insects in the meadows, the hibernation of the bear are only a negligible part of the examples of the seasonal dynamics of the animal population of the biocenosis.

Decomposers differ from animal-detritophages primarily in that they do not leave solid undigested residues (excrement). Decomposers return mineral salts to soil and water, making them available to producers - autotrophs, and thus close the biotic cycle. Therefore, ecosystems cannot do without decomposers (in contrast to consumers, which were probably absent in ecosystems during the first 2 billion years of evolution, when ecosystems consisted of only prokaryotes).