The levels of organization of living systems represent a certain orderliness, a hierarchical system, which is one of the main properties of living things, see Table. 2.

table 2

Each living system consists of units of organizational levels subordinate to it and is a unit that is part of the living system to which it is subordinate. For example, an organism consists of cells that are living systems, and is part of underorganismal biosystems (populations, biocenoses).

The existence of life at all levels is prepared and determined by the structure of the lowest level:

The nature of the cellular level of organization is determined by the molecular level; The nature of the organism - cellular; population-species - organismal, etc.

1. Molecular level. The molecular level bears separate, albeit essential, signs of life. At this level, a surprising uniformity of discrete units is revealed. The basis of all animals, plants and viruses is 20 amino acids and 4 identical bases that make up nucleic acid molecules. In all organisms, biological energy is stored in the form of energy-rich adenosine triphosphate (ATP). Hereditary information for all is embedded in the molecules of dioxyribonucleic acid (DNA), capable of self-reproduction. The implementation of hereditary information is carried out with the participation of ribonucleic acid (RNA) molecules.

2. Cellular level. The cell is the basic independently functioning elementary biological unit, characteristic of all living organisms. In all organisms, biosynthesis and realization of hereditary information are possible only at the cellular level. The cellular level in unicellular organisms coincides with the organism level. There was a period in the history of life on our planet (the first half of the Proterozoic era ~ 2000 million years ago) when all organisms were at this level of organization. All species, biocenoses and the biosphere as a whole consisted of such organisms.

3. Tissue level. A collection of cells with the same type of organization constitutes a tissue. The tissue level arose along with the appearance of multicellular animals and plants with tissues that differ from each other. A great similarity between all organisms is preserved at the tissue level.

4. Organ level. Jointly functioning cells belonging to different tissues make up organs. (Only six basic tissues are part of the organs of all animals and six basic tissues form organs in plants).

5. Organism level. At the organismic level, an extremely large variety of forms is found. The diversity of organisms belonging to different species, as well as within the same species, is explained not by the diversity of discrete lower-order units (cells, tissues, organs), but by the complication of their combinations, which provide the qualitative features of organisms. There are currently over a million animal species and about half a million plant species on Earth. Each species consists of separate individuals (organisms, individuals), which have their own distinctive features.

6. Population-species level. A set of organisms of the same species inhabiting a certain area constitutes a population. A population is an underorganized living system, which is an elementary unit of the evolutionary process; it begins the process of speciation. The population is part of biocenoses.

7. Biocenotic level. Biogeocenoses are historically established stable communities of populations of various species, connected with each other and the environment by the exchange of substances, energy and information. They are elementary systems in which the material-energy cycle is carried out, due to the vital activity of organisms.

8. Biosphere level. The totality of biogeocenoses make up: the biosphere and determine all the processes occurring in it.

Thus, we see that the question of structural levels in biology has some peculiarities in comparison with its consideration in physics. This feature consists in the fact that the study of each level of organization in biology sets as its main goal the explanation of the phenomenon of life. Indeed, if in physics the division into structural levels of matter is rather arbitrary (the criteria here are mass and dimensions), then the levels of matter in biology differ not so much in size or levels of complexity, but mainly in the patterns of functioning.

Indeed, if, for example, a researcher has studied the physicochemical properties of a biological object and its structure, but has not established its biological purpose in an integral system, this will mean that another specific object has been studied, but not the level of living matter.

Another feature of the structuring of living matter is hierarchical [ 2] subordination levels. This means that the lower levels as a whole are included in the higher ones. This concept of structuring has been called the "multi-level hierarchical matryoshka".

It is also important to note that the number of levels allocated in biology depends on the depth of professional study of the living world.

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test questions

1. Define biology. What is the subject matter of biology? 2. Name the main methods of biology. 3. List the main classifications of biological sciences. 4. Describe traditional (naturalistic) biology. 5. What are the features of physical and chemical biology?

6. What does molecular biology study? 7. List the main experimental methods of physical and chemical biology. 8. What does evolutionary biology study? 9. What is theoretical biology? List the main prerequisites (theoretical provisions) for its creation. 10. What is a biological system?

11. What are the three main system properties of the living. 12. List the main qualities of living systems. 13. What is the openness of living systems? 14. Explain the statement: "Living systems are self-governing and self-organizing." 15. What is the irritability of living systems?

16. “The only way to define a living thing is ...” (continue). 17. What is the peculiarity of structural levels in biology in comparison with the structuring of matter in physics? 18. What is the concept of a multi-level hierarchical "matryoshka"? 19. List the structural levels of organization of the living. 20. What is a population? 21. What is biogeocenosis? ecological system?

Literature

1. Tulinov V.D., Nedelsky N.F., Oleinikov B.I. Concepts of modern natural science, M.: MUPC, 1995. 2. Kuznetsov V.I., Idlis G.M., Gutina V.N. Natural science M.: Agar, 1995. 3. Gryadovoy D.I. Concepts of modern natural science, M.: Uchpediz, 1995. 4. Diaghilev F.M. Concepts of modern natural science, Moscow: IMPE, 1998. 5. Yablokov A.V., Yusufov A.G. evolutionary doctrine. - M .: Higher School, 1998.

[ 1] Chirality is the mirror asymmetry of molecules. Molecules from which living matter is formed can have only one orientation - “left” or “right”. For example, the DNA molecule has the form of a helix, and this helix is ​​always right.

[ 2] Hierarchy - the arrangement of parts or elements of a whole in order from highest to lowest

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The rights to distribute and use the course belong to Ufa State Aviation Technical University

All living organisms in nature consist of the same levels of organization; this is a characteristic biological pattern common to all living organisms. The following levels of organization of living organisms are distinguished - molecular, cellular, tissue, organ, organism, population-species, biogeocenotic, biospheric.

1. Molecular genetic level. This is the most elementary level characteristic of life. No matter how complex or simple the structure of any living organism, they all consist of the same molecular compounds. An example of this is nucleic acids, proteins, carbohydrates and other complex molecular complexes of organic and inorganic substances. They are sometimes called biological macromolecular substances. At the molecular level, various life processes of living organisms take place: metabolism, energy conversion. With the help of the molecular level, the transfer of hereditary information is carried out, individual organelles are formed and other processes occur.

2. Cellular level. The cell is the structural and functional unit of all living organisms on Earth. Individual organelles in the cell have a characteristic structure and perform a specific function. The functions of individual organelles in the cell are interconnected and perform common life processes. In unicellular organisms, all life processes take place in one cell, and one cell exists as a separate organism (unicellular algae, chlamydomonas, chlorella and protozoa - amoeba, ciliates, etc.). In multicellular organisms, one cell cannot exist as a separate organism, but it is the elementary structural unit of the organism.

3. Tissue level.

A set of cells and intercellular substances similar in origin, structure and functions forms a tissue. The tissue level is typical only for multicellular organisms. Also, individual tissues are not an independent holistic organism. For example, the bodies of animals and humans are made up of four different tissues (epithelial, connective, muscle, and nervous). Plant tissues are called: educational, integumentary, supporting, conductive and excretory.

4.Organ level.

In multicellular organisms, the union of several identical tissues, similar in structure, origin and functions, forms the organ level. Each organ contains several tissues, but among them one is the most significant. A separate organ cannot exist as a whole organism. Several organs, similar in structure and function, unite to form an organ system, for example, digestion, respiration, blood circulation, etc.

5. Organism level.

Plants (chlamydomonas, chlorella) and animals (amoeba, infusoria, etc.), whose bodies consist of one cell, are an independent organism. A separate individual of multicellular organisms is considered as a separate organism. In each individual organism, all the vital processes characteristic of all living organisms take place - nutrition, respiration, metabolism, irritability, reproduction, etc. Each independent organism leaves behind offspring. In multicellular organisms, cells, tissues, organs and organ systems are not a separate organism. Only an integral system of organs specialized in performing various functions forms a separate independent organism. The development of an organism, from fertilization to the end of life, takes a certain period of time. This individual development of each organism is called ontogeny. An organism can exist in close relationship with the environment.

6. Population-species level.

An aggregate of individuals of one species or a group that exists for a long time in a certain part of the range relatively apart from other aggregates of the same species constitutes a population. At the population level, the simplest evolutionary transformations are carried out, which contributes to the gradual emergence of a new species.

7. Biogeocenotic level.

The totality of organisms of different species and organization of varying complexity, adapted to the same environmental conditions, is called a biogeocenosis, or natural community. The composition of biogeocenosis includes numerous types of living organisms and environmental conditions. In natural biogeocenoses, energy is accumulated and transferred from one organism to another. Biogeocenosis includes inorganic, organic compounds and living organisms.

8. Biosphere level.

The totality of all living organisms on our planet and their common natural habitat constitutes the biospheric level. At the biospheric level, modern biology solves global problems, such as determining the intensity of the formation of free oxygen by the Earth's vegetation cover or changes in the concentration of carbon dioxide in the atmosphere associated with human activities. The main role in the biospheric level is played by "living substances", that is, the totality of living organisms that inhabit the Earth. Also at the biosphere level, "bio-inert substances", formed as a result of the vital activity of living organisms and "inert" substances, i.e., environmental conditions, matter. At the biospheric level, the circulation of substances and energy on Earth takes place with the participation of all living organisms of the biosphere.

What organs does a flowering plant have? What animal organ systems do you know?

Root, stem, leaf, flower

Circulatory, musculoskeletal, sexual, respiratory, endocrine, nervous, digestive

1. List the organ systems known to you.

Circulatory, musculoskeletal, sexual, endocrine, nervous, digestive, urinary, respiratory, immune.

2. Why are the skeleton and muscles considered together?

Integumentary, musculoskeletal, circulatory.

3. Which organ systems perform an executive, and which regulatory function?

One of the functions of the human body is to change the position of body parts, movement in space. Movements occur with the participation of bones that act as levers, and skeletal muscles, which, together with bones and their joints, form the musculoskeletal system. Bones and bone joints make up the passive part of the musculoskeletal system, and the muscles that perform the functions of contracting and changing the position of the bones are the active part.

4. List the functions of the endocrine system.

Digestive, circulatory, respiratory, excretory.

5. Which organ systems perform an executive and which regulatory function?

The executive ones include - musculoskeletal, circulatory, immune, respiratory, digestive, excretory. To regulatory - nervous and endocrine.

6. List the functions of the nervous system

The nervous system regulates the work of organs, ensures their coordinated activity and adaptation to environmental conditions. Through the sense organs - eyes, ears, nose, tongue, skin - it communicates with the environment. Thanks to the nervous system, the mental activity of a person is carried out, his behavior is regulated.

7. List the functions of the endocrine system.

The endocrine system includes endocrine glands that secrete hormones - biological regulators that act humorally - through the blood and body fluids. The endocrine glands include the pituitary gland, thyroid gland, pancreas, gonads, adrenal glands, etc. Hormones are secreted directly into the blood or lymph and affect many target organs that are sensitive to them. Hormones can both enhance the work of organs and slow it down.

8. What levels of body organization do you know?

Each organism is characterized by a certain organization of its structures. There are six levels of organization of the human body:

1) molecular;

2) cellular:

3) tissue;

4) organ;

5) system.

6) organismic.

9. Describe the action of nervous and humoral regulation.

Nervous and humoral regulation complement each other. The nervous one is carried out quickly and directionally, the humoral one is slower, but it covers many organs and systems. Together with the autonomic nervous system, humoral regulation activates (or inhibits) the work of smooth muscles and internal organs.

The following levels of life organization are distinguished: molecular, cellular, organ-tissue (sometimes they are separated), organismic, population-species, biogeocenotic, biospheric. Living nature is a system, and the various levels of its organization form its complex hierarchical structure, when the underlying simpler levels determine the properties of the overlying ones.

So complex organic molecules are part of the cells and determine their structure and vital activity. In multicellular organisms, cells are organized into tissues, and several tissues form an organ. A multicellular organism consists of organ systems, on the other hand, the organism itself is an elementary unit of a population and biological species. The community is represented by interacting populations of different species. The community and the environment form a biogeocenosis (ecosystem). The totality of ecosystems of the planet Earth forms its biosphere.

At each level, new properties of living things arise, which are absent at the underlying level, their own elementary phenomena and elementary units are distinguished. At the same time, the levels largely reflect the course of the evolutionary process.

The allocation of levels is convenient for studying life as a complex natural phenomenon.

Let's take a closer look at each level of organization of life.

Molecular level

Although molecules are made up of atoms, the difference between living matter and non-living matter begins to manifest itself only at the level of molecules. Only the composition of living organisms includes a large number of complex organic substances - biopolymers (proteins, fats, carbohydrates, nucleic acids). However, the molecular level of organization of living things also includes inorganic molecules that enter cells and play an important role in their life.

The functioning of biological molecules underlies the living system. At the molecular level of life, metabolism and energy conversion are manifested as chemical reactions, the transfer and change of hereditary information (reduplication and mutations), as well as a number of other cellular processes. Sometimes the molecular level is called the molecular genetic level.

Cellular level of life

It is the cell that is the structural and functional unit of the living. There is no life outside the cell. Even viruses can exhibit the properties of a living being only once they are in the host cell. Biopolymers fully show their reactivity when organized in a cell, which can be considered as a complex system of molecules interconnected primarily by various chemical reactions.

At this cellular level, the phenomenon of life manifests itself, the mechanisms of transmission of genetic information and the transformation of substances and energy are conjugated.

Organ tissue

Only multicellular organisms have tissues. Tissue is a collection of cells similar in structure and function.

Tissues are formed in the process of ontogenesis by differentiation of cells that have the same genetic information. At this level, cell specialization occurs.

Plants and animals have different types of tissues. So in plants it is a meristem, a protective, basic and conductive tissue. In animals - epithelial, connective, muscular and nervous. The fabrics may include a list of subfabrics.

An organ usually consists of several tissues, united among themselves in a structural and functional unity.

Organs form organ systems, each of which is responsible for an important function for the body.

The organ level in unicellular organisms is represented by various cell organelles that perform the functions of digestion, excretion, respiration, etc.

Organismal level of organization of living

Along with the cellular at the organismal (or ontogenetic) level, separate structural units are distinguished. Tissues and organs cannot live independently, organisms and cells (if it is a unicellular organism) can.

Multicellular organisms are made up of organ systems.

At the organismic level, such phenomena of life as reproduction, ontogenesis, metabolism, irritability, neurohumoral regulation, homeostasis are manifested. In other words, its elementary phenomena constitute regular changes in the organism in individual development. The elementary unit is the individual.

population-species

Organisms of the same species, united by a common habitat, form a population. A species usually consists of many populations.

Populations share a common gene pool. Within a species, they can exchange genes, that is, they are genetically open systems.

In populations, elementary evolutionary phenomena occur, ultimately leading to speciation. Living nature can evolve only in supra-organismal levels.

At this level, the potential immortality of the living arises.

Biogeocenotic level

Biogeocenosis is an interacting set of organisms of different species with different environmental factors. Elementary phenomena are represented by matter-energy cycles, provided primarily by living organisms.

The role of the biogeocenotic level consists in the formation of stable communities of organisms of different species, adapted to living together in a certain habitat.

Biosphere

The biospheric level of life organization is a higher-order system of life on Earth. The biosphere encompasses all manifestations of life on the planet. At this level, the global circulation of substances and the flow of energy (covering all biogeocenoses) take place.

All living organisms in nature consist of the same levels of organization; this is a characteristic biological pattern common to all living organisms.
The following levels of organization of living organisms are distinguished - molecular, cellular, tissue, organ, organism, population-species, biogeocenotic, biospheric.

Rice. 1. Molecular genetic level

1. Molecular genetic level. This is the most elementary level characteristic of life (Fig. 1). No matter how complex or simple the structure of any living organism, they all consist of the same molecular compounds. An example of this is nucleic acids, proteins, carbohydrates and other complex molecular complexes of organic and inorganic substances. They are sometimes called biological macromolecular substances. At the molecular level, various life processes of living organisms take place: metabolism, energy conversion. With the help of the molecular level, the transfer of hereditary information is carried out, individual organelles are formed and other processes occur.

Rice. 2. Cellular level

2. Cellular level. The cell is the structural and functional unit of all living organisms on Earth (Fig. 2). Individual organelles in the cell have a characteristic structure and perform a specific function. The functions of individual organelles in the cell are interconnected and perform common life processes. In unicellular organisms (unicellular algae and protozoa), all life processes take place in one cell, and one cell exists as a separate organism. Remember unicellular algae, chlamydomonas, chlorella and protozoa - amoeba, infusoria, etc. In multicellular organisms, one cell cannot exist as a separate organism, but it is an elementary structural unit of the organism.

Rice. 3. Tissue level

3. Tissue level. A set of cells and intercellular substances similar in origin, structure and functions forms a tissue. The tissue level is typical only for multicellular organisms. Also, individual tissues are not an independent integral organism (Fig. 3). For example, the bodies of animals and humans are made up of four different tissues (epithelial, connective, muscle, and nervous). Plant tissues are called: educational, integumentary, supporting, conductive and excretory. Recall the structure and functions of individual tissues.

Rice. 4. Organ level

4. Organ level. In multicellular organisms, the union of several identical tissues, similar in structure, origin, and functions, forms the organ level (Fig. 4). Each organ contains several tissues, but among them one is the most significant. A separate organ cannot exist as a whole organism. Several organs, similar in structure and function, unite to form an organ system, for example, digestion, respiration, blood circulation, etc.

Rice. 5. Organism level

5. Organism level. Plants (chlamydomonas, chlorella) and animals (amoeba, infusoria, etc.), whose bodies consist of one cell, are an independent organism (Fig. 5). A separate individual of multicellular organisms is considered as a separate organism. In each individual organism, all the vital processes characteristic of all living organisms take place - nutrition, respiration, metabolism, irritability, reproduction, etc. Each independent organism leaves behind offspring. In multicellular organisms, cells, tissues, organs and organ systems are not a separate organism. Only an integral system of organs specialized in performing various functions forms a separate independent organism. The development of an organism, from fertilization to the end of life, takes a certain period of time. This individual development of each organism is called ontogeny. An organism can exist in close relationship with the environment.

Rice. 6. Population-species level

6. Population-species level. A set of individuals of one species or group that exists for a long time in a certain part of the range relatively apart from other sets of the same species constitutes a population. At the population level, the simplest evolutionary transformations are carried out, which contributes to the gradual emergence of a new species (Fig. 6).

Rice. 7 Biogeocenotic level

7. Biogeocenotic level. The totality of organisms of different species and organization of varying complexity, adapted to the same environmental conditions, is called a biogeocenosis, or natural community. The composition of biogeocenosis includes numerous types of living organisms and environmental conditions. In natural biogeocenoses, energy is accumulated and transferred from one organism to another. Biogeocenosis includes inorganic, organic compounds and living organisms (Fig. 7).

Rice. 8. Biosphere level

8. Biosphere level. The totality of all living organisms on our planet and their common natural habitat constitutes the biospheric level (Fig. 8). At the biospheric level, modern biology solves global problems, such as determining the intensity of the formation of free oxygen by the Earth's vegetation cover or changes in the concentration of carbon dioxide in the atmosphere associated with human activities. The main role at the biospheric level is played by "living substances", that is, the totality of living organisms that inhabit the Earth. Also at the biospheric level, "bio-inert substances" are important, formed as a result of the vital activity of living organisms and "inert" substances (i.e., environmental conditions). At the biospheric level, the circulation of substances and energy on Earth takes place with the participation of all living organisms of the biosphere.

levels of organization of life. population. Biogeocenosis. Biosphere.

1. Currently, there are several levels of organization of living organisms: molecular, cellular, tissue, organ, organism, population-species, biogeocenotic and biospheric.
2. At the population-species level, elementary evolutionary transformations are carried out.
3. The cell is the most elementary structural and functional unit of all living organisms.
4. A set of cells and intercellular substances similar in origin, structure and functions forms a tissue.
5. The totality of all living organisms on the planet and their common natural habitat constitutes the biospheric level.
1. List the levels of organization in order.
2. What is fabric?
3. What are the main parts of a cell?
1. What organisms are characterized by the tissue level?
2. Describe the organ level.
3. What is a population?
1. Describe the organism level.
2. Name the features of the biogeocenotic level.
3. Give examples of the interconnectedness of the levels of organization of life.

Complete the table showing the structural features of each level of the organization:

Serial number	Organization levels	Peculiarities