LEVELS OF LIVING ORGANIZATION
There are molecular, cellular, tissue, organ, organism, population, species, biocenotic and global (biospheric) levels of organization of the living. At all these levels, all the properties characteristic of living things are manifested. Each of these levels is characterized by features inherent in other levels, but each level has its own specific features.
Molecular level. This level is deep in the organization of the living and is represented by molecules of nucleic acids, proteins, carbohydrates, lipids and steroids that are in cells and are called biological molecules. At this level, the most important processes of vital activity (coding and transmission of hereditary information, respiration, metabolism and energy metabolism, variability, etc.) are initiated and carried out. The physical and chemical specificity of this level lies in the fact that the composition of the living includes a large number of chemical elements, but the bulk of the living is represented by carbon, oxygen, hydrogen and nitrogen. Molecules are formed from a group of atoms, and complex chemical compounds are formed from the latter, differing in structure and function. Most of these compounds in cells are represented by nucleic acids and proteins, the macromolecules of which are polymers synthesized as a result of the formation of monomers and the combination of the latter in a certain order. In addition, the monomers of macromolecules within the same compound have the same chemical groups and are connected using chemical bonds between atoms, their non-specific
ical parts (areas). All macromolecules are universal, as they are built according to the same plan, regardless of their species. Being universal, they are at the same time unique, because their structure is unique. For example, the composition of DNA nucleotides includes one nitrogenous base of the four known (adenine, guanine, cytosine or thymine), as a result of which any nucleotide is unique in its composition. The secondary structure of DNA molecules is also unique.
The biological specificity of the molecular level is determined by the functional specificity of biological molecules. For example, the specificity of nucleic acids lies in the fact that they encode the genetic information for protein synthesis. Moreover, these processes are carried out as a result of the same stages of metabolism. For example, the biosynthesis of nucleic acids, amino acids, and proteins follows a similar pattern in all organisms. Fatty acid oxidation, glycolysis, and other reactions are also universal.
The specificity of proteins is determined by the specific sequence of amino acids in their molecules. This sequence further determines the specific biological properties of proteins, since they are the main structural elements of cells, catalysts and regulators of reactions in cells. Carbohydrates and lipids serve as the most important sources of energy, while steroids are important for the regulation of a number of metabolic processes.
At the molecular level, energy is converted - radiant energy into chemical energy stored in carbohydrates and other chemical compounds, and the chemical energy of carbohydrates and other molecules - into biologically available energy stored in the form of macroergic bonds of ATP. Finally, here the energy of macroergic phosphate bonds is converted into work - mechanical, electrical, chemical, osmotic. The mechanisms of all metabolic and energy processes are universal.
Biological molecules also provide continuity between molecules and the next level (cellular), since they are the material from which supramolecular structures are formed. The molecular level is the "arena" of chemical reactions that provide energy to the cellular level.
Cellular level. This level of organization of the living is represented by cells acting as independent organizations.
mov (bacteria, protozoa, etc.), as well as cells of multicellular organisms. The main specific feature of this level is that life begins from it. Being capable of life, growth and reproduction, cells are the main form of organization of living matter, the elementary units from which all living beings (prokaryotes and eukaryotes) are built. There are no fundamental differences in structure and function between plant and animal cells. Some differences relate only to the structure of their membranes and individual organelles. There are noticeable differences in structure between prokaryotic cells and eukaryotic cells, but in functional terms, these differences are leveled, because the “cell from cell” rule applies everywhere.
The specificity of the cellular level is determined by the specialization of cells, the existence of cells as specialized units of a multicellular organism. At the cellular level, there is a differentiation and ordering of vital processes in space and time, which is associated with the confinement of functions to different subcellular structures. For example, eukaryotic cells have significantly developed membrane systems (plasma membrane, cytoplasmic reticulum, lamellar complex) and cell organelles (nucleus, chromosomes, centrioles, mitochondria, plastids, lysosomes, ribosomes). Membrane structures are the "arena" of the most important life processes, and the two-layer structure of the membrane system significantly increases the area of the "arena". In addition, membrane structures provide spatial separation of many biological molecules in cells, and their physical state allows for the constant diffuse movement of some of the protein and phospholipid molecules contained in them. Thus, membranes are a system whose components are in motion. They are characterized by various rearrangements, which determines the irritability of cells - the most important property of the living.
tissue level. This level is represented by tissues that combine cells of a certain structure, size, location and similar functions. Tissues arose in the course of historical development along with multicellularity. In multicellular organisms, they are formed during ontogenesis as a result of cell differentiation. In animals, several types of tissues are distinguished (epithelial, connective, muscle, blood, nervous and reproductive). The races
shadows distinguish meristematic, protective, basic and conductive tissues. At this level, cell specialization occurs.
Organ level. Represented by organs of organisms. In plants and animals, organs are formed due to a different number of tissues. In protozoa, digestion, respiration, circulation of substances, excretion, movement and reproduction are carried out by various organelles. More advanced organisms have organ systems. Vertebrates are characterized by cephalization, which consists in the concentration of the most important nerve centers and sensory organs in the head.
Organism level. This level is represented by the organisms themselves - unicellular and multicellular organisms of plant and animal nature. A specific feature of the organismic level is that at this level the decoding and implementation of genetic information, the creation of structural and functional features inherent in organisms of a given species take place.
species level. This level is determined by plant and animal species. Currently, there are about 500 thousand plant species and about 1.5 million animal species, whose representatives are characterized by a wide variety of habitats and occupy different ecological niches. A species is also a unit of classification of living beings.
population level. Plants and animals do not exist in isolation; they are united in populations that are characterized by a certain gene pool. Within the same species, there can be from one to many thousands of populations. Elementary evolutionary transformations are carried out in populations, a new adaptive form is being developed.
Biocenotic level. It is represented by biocenoses - communities of organisms of different species. In such communities, organisms of different species depend to some extent on each other. In the course of historical development, biogeocenoses (ecosystems) have developed, which are systems consisting of interdependent communities of organisms and abiotic environmental factors. Ecosystems have a fluid balance between organisms and abiotic factors. At that level, the material-energy cycles associated with the vital activity of organisms are carried out.
Global (biospheric) level. This level is the highest form of organization of the living (living systems). It is represented by the biosphere. At this level, all matter-energy cycles are united into a single giant biospheric cycle of substances and energy.
There is a dialectical unity between different levels of organization of the living. The living is organized according to the type of systemic organization, the basis of which is the hierarchy of systems. The transition from one level to another is associated with the preservation of the functional mechanisms operating at the previous levels, and is accompanied by the appearance of a structure and functions of new types, as well as an interaction characterized by new features, i.e., a new quality appears.
The living nature of our planet is characterized by complex, hierarchical correlation of organizational levels. The entire organic world and the environment form a biosphere, which, in turn, consists of biogeocenoses (ecosystems) - territories with characteristic natural conditions and certain plant and animal complexes (biocenoses). Biocenoses are formed by populations - groups of plant and animal organisms of the same species living in a certain area and capable of producing. Populations consist of representatives of specific species (individuals) that are able to interbreed freely and produce fertile offspring. Multicellular organisms are composed of organs and tissues formed by cells. Unicellular organisms and cells are formed by intracellular structures that consist of molecules.
Based on this, distinguish several levels of organization of living matter.
Each level of organization of living organisms is characterized by its own patterns associated with its specific principles of organization, features of the relationship with other levels.
General biology studies the basic patterns of life phenomena that occur at various levels of organization of the living. Consideration of the organization of living matter begins with the elucidation of the structure and properties of complex organic molecules. Cells of multicellular organisms are part of tissues, two or more tissues form an organ. A multicellular organism has a complex structure, which consists of tissues and organs, at the same time it is an elementary unit of a biological species. Interacting with each other, species form a community, or an ecological system, which, in turn, is one of the components of the biosphere.
Each level of organization of organisms is studied by the corresponding branches of biology.
Molecular level
Remark 1
Any living system, no matter how complex it is organized, is determined at the level of functioning of biological macromolecules - biopolymers: nucleic acids, proteins, polysaccharides, as well as other important organic substances. From this level, the most important processes of the organism's vital activity begin: metabolism and energy conversion, transmission of hereditary information, etc.
Molecular biology, molecular genetics, physiology, cytochemistry, biochemistry, biophysics, certain sections of virology, microbiology study the physicochemical processes that occur in a living organism (synthesis, decomposition and mutual transformations of proteins, nucleic acids, polysaccharides, lipids and other substances in the cell; metabolism, energy and information that regulate these processes).
Such studies of living systems have shown that they consist of low- and high-molecular organic compounds, which are almost impossible to detect in inanimate nature. For living organisms, biopolymers such as proteins, nucleic acids, polysaccharides, lipids (fat-like compounds) and their constituent molecules (amino acids, nucleotides, monosaccharides, fatty acids) are most characteristic. Also, at this level, the synthesis, decay and mutual transformations of these compounds in cells, the metabolism, energy and information, the regulation of these processes are studied.
As a result of these studies, it was found that the most important feature of the main metabolic pathways is the action of biological catalysts - enzymes(protein compounds), which strictly selectively affect the rate of chemical reactions. The structure of some amino acids, a number of proteins and many simple organic compounds has also been studied. It has been established that the chemical energy released during biological oxidation (respiration processes, glycolysis) is stored in the form of energy-rich compounds (mainly adenosine phosphoric acids ATP, ADP, etc.), and then used in processes that require energy (muscle contractions, synthesis and transport of substances). A major success was the discovery of the genetic code. It has been found that the heredity encoded in DNA through enzyme proteins controls both structural proteins and all the basic properties of cells and the organism as a whole.
Research at the molecular level requires the isolation and study of all types of molecules that make up the cell, the disclosure of their relationship with each other.
Used research methods at the molecular level:
- electrophoresis (to separate macromolecules using their differences in charges);
- ultracentrifugation (to separate macromolecules using their differences in density and size);
- chromatography (for the separation of macromolecules using their differences in adsorption properties);
- x-ray diffraction analysis (they study the mutual spatial arrangement of atoms in complex molecules);
- radioisotopes (study of the ways of transformation of substances, the rate of their synthesis and decay);
- artificial modeling of systems from isolated cellular elements (reproduction of processes occurring in a cell - all biochemical processes in a cell do not occur in a homogeneous mixture of substances, but on certain cellular structures).
Cellular level
At the cellular level cytology, histology, and their departments (karyology, cyto- and histochemistry, cytophysiology, cytogenetics), many sections of physiology, microbiology and virology study the structure of the cell and internal cellular components, as well as the connections and relationships between cells in tissues and organs of the body. Free-living non-cellular life forms do not exist.
Cell- the main independent functional and structural unit of a multicellular organism. There are unicellular organisms (algae, fungi, protozoa, bacteria). Also, the cell is a unit of development of all living organisms that exist on Earth. The properties of a cell are determined by its components that perform various functions.
Thanks to research at the cellular level, the main components of the cell, the structure of cells and tissues, and their changes in the development process have been studied.
Research methods at the cellular level:
- microscopy (light microscope allows you to see objects up to 1 micron);
- color histochemical reactions (detection of localization in the cell of various chemicals and enzymes);
- autoradiography (detection of sites in the cell for the synthesis of macromolecules);
- electron microscopy (distinguishing structures down to macromolecules, although the description of their structure is often difficult due to insufficient image contrast);
- centrifugation (study of the functions of intracellular components - they are isolated from destroyed (homogenized) cells);
- tissue culture (study of cell properties);
- microsurgery (exchange of nuclei between cells, fusion (hybridization) of cells.
tissue level
A tissue is a collection of cells similar in structure, united by the performance of a common function. Hundreds of diverse cells enter into the body of a variety of multicellular organisms. A variety of animal cells form $4$ tissue types: nervous, connective, epithelial, and muscle. Plants are divided into forming and permanent tissues. Permanent tissues include integumentary, conductive, mechanical and underlying tissue.
Organ level
Definition 2
Organs are highly differentiated body parts that are located in a specific place and perform special functions. These are structural and functional associations of several types of tissues. They are formed during development from cells of various tissues.
Groups of different organs collectively function to perform a common function for the body. A person has the following organ systems: digestive, respiratory, cardiovascular, nervous, secretory, excretory, reproductive, endocrine, muscular, skeletal and integumentary tissue systems. Each individual organ of the system performs a specific function, but all work together as one "team", ensuring maximum efficiency of the entire system. All organ systems function in interconnection and are regulated by the nervous and endocrine systems. Violation of the functioning of any organ leads to the pathology of the entire system and even the body.
Organism level
Physiology (plants and animals, higher nervous activity), experimental morphology, endocrinology, embryology, immunology, and also a number of other biological branches study the processes and phenomena occurring in an individual, and the coordinated functioning of its organs and systems.
At this level, in order to create a general theory of ontogenesis, research is carried out aimed at revealing the causal mechanisms of the formation of a biological organization, its differentiation and integration, and the implementation of genetic information in ontogenesis. The mechanisms of the functioning of organs and their systems, their role in the life of the body, mutual influences of organs, nervous and humoral regulation of their functions, animal behavior, adaptive changes, etc. are also studied.
At this level, the mechanism of the functioning of organs and systems, their role in the life of the organism, the relationship of organs, the behavior of organisms, and adaptive changes are also studied.
The following research methods are currently being used:
- electrophysiological(they consist in the removal, amplification and registration of bioelectric potentials);
- biochemical(the study of endocrine regulation is being carried out - the release and purification of hormones, the synthesis of their analogues, the study of biosynthesis and the mechanisms of action of hormones);
- cybernetic(study of GNI of animals and humans by modeling method);
- experimental(development of conditioned reflexes, setting tasks).
Population - species level
Definition 3
Certain branches of biology (morphology, physiology, genetics, ecology) study the elementary unit of the evolutionary process - population- a set of individuals of the same species inhabiting a certain territory, more or less isolated from neighboring groups.
The study of the composition and dynamics of a population is inextricably linked to the molecular, cellular, and organismal levels.
Research methods are the methods of those sciences that study the questions specifically posed at this level:
- genetic methods - the nature of the distribution of hereditary characteristics in populations;
- morphological
- physiological
- ecological.
The population and the species as a whole can serve as objects of study in various biological branches.
Biogeocenotic, or biospheric, level
Definition 4
Biogeocenology, ecology, biogeochemistry and other branches of biology study the processes occurring in biogeocenoses(ecosystems) - elementary structural and functional units of the biosphere.
At this level, comprehensive studies are being carried out covering the relationship of biotic and abiotic components that are part of the biogeocenosis; the movement of living matter in the biosphere, the ways and patterns of the flow of energy circuits are studied. This approach makes it possible to foresee the consequences of human economic activity and, in the form of the international program "Man and the Biosphere", to coordinate the efforts of biologists from many countries.
Of great practical importance is the study of the biological productivity of biogeocenoses (utilization of the energy of solar radiation through photosynthesis and the use by heterotrophic organisms of the energy stored by autotrophs).
Remark 2
The need for a detailed study of the biospheric level of organization of living things is due to the fact that biogeocenoses are the environment in which any life processes take place on our planet.
Organization levels living systems reflect the subordination, hierarchy of the structural organization of life; differ from each other in the complexity of the organization of the system (the cell is simpler in comparison with a multicellular organism or population).
Standard of living - this is the form and way of its existence (the virus exists in the form of a DNA or RNA molecule enclosed in a protein shell - the form of the existence of the virus. However, the properties of a living system the virus shows only when it enters the cell of another organism, where it multiplies - the way it exists).
Organization levels |
Biological system |
The components that make up the system |
Core Processes |
|
1. |
Molecule |
Separate biopolymers (DNA, RNA, proteins, lipids, carbohydrates, etc.); |
At this level of life, phenomena associated with changes (mutations) and the reproduction of genetic material, metabolism are studied. |
|
2. |
Complexes of molecules of chemical compounds and cell organelles |
Synthesis of specific organic substances; regulation of chemical reactions; cell division; the involvement of the chemical elements of the Earth and the energy of the Sun in biosystems |
|
|
3. |
Cells and intercellular substance |
Metabolism; irritability |
|
|
4. |
Fabrics of different types |
Digestion; gas exchange; transport of substances; movement, etc. |
|
|
5. Organismic |
organism |
Organ systems |
Metabolism; irritability; reproduction; ontogenesis. Neuro-humoral regulation of vital processes. Ensuring harmonious conformity of the organism to its environment |
|
6. Population-species |
population |
Groups of related individuals united by a certain gene pool and specific interaction with the environment |
genetic identity; interaction between individuals and populations; accumulation of elementary evolutionary transformations; development of adaptation to changing environmental conditions |
|
7. |
Biogeocenosis |
Populations of different species; environmental factors; space with a complex of environmental conditions |
The biological cycle of substances and the flow of energy that support life; mobile balance between the living population and the abiotic environment; providing the living population with living conditions and resources |
|
8. |
Biosphere |
Biogeocenoses and anthropogenic impact |
Active interaction of living and non-living (inert) matter of the planet; biological global circulation; active biogeochemical participation of man in all processes of the biosphere |
THEMATIC ASSIGNMENTS
Part A
A1. The level at which the processes of biogenic migration of atoms are studied is called:
1) biogeocenotic
2) biosphere
3) population-species
4) molecular genetic
A2. At the population-species level, they study:
1) gene mutations
2) the relationship of organisms of the same species
3) organ systems
4) metabolic processes in the body
A3. Maintaining a relatively constant chemical composition of the body is called
1) metabolism
2) assimilation
3) homeostasis
4) adaptation
A4. The occurrence of mutations is associated with such a property of the organism as
1) heredity
2) variability
3) irritability
4) self-reproduction
A5. Which of the following biological systems forms the highest standard of living?
1) amoeba cell
2) smallpox virus
3) a herd of deer
4) nature reserve
A6. Pulling the hand away from a hot object is an example
1) irritability
2) ability to adapt
3) inheritance of traits from parents
4) self-regulation
A7. Photosynthesis, protein biosynthesis are examples
1) plastic metabolism
2) energy metabolism
3) nutrition and breathing
4) homeostasis
A8. Which of the terms is synonymous with the concept of "metabolism"?
1) anabolism
2) catabolism
3) assimilation
4) metabolism
Part B
IN 1. Select the processes studied at the molecular genetic level of life:
1) DNA replication
2) inheritance of Down's disease
3) enzymatic reactions
4) the structure of mitochondria
5) cell membrane structure
6) blood circulation
IN 2. Correlate the nature of the adaptation of organisms with the conditions to which they were developed.
Part C
C1. What adaptations of plants provide them with reproduction and resettlement?
C2. What is common and what are the differences between different levels of organization of life?
The levels of organization of the organic world are discrete states of biological systems, characterized by subordination, interconnectedness, and specific patterns.
Structural levels of life organization are extremely diverse, but the main ones are molecular, cellular, ontogenetic, population-species, biocenotic and biospheric.
1. Molecular genetic standard of living. The most important tasks of biology at this stage is the study of the mechanisms of transmission of genetic information, heredity and variability.
There are several mechanisms of variability at the molecular level. The most important of them is the mechanism of gene mutation - the direct transformation of the genes themselves under the influence of external factors. The factors causing the mutation are: radiation, toxic chemical compounds, viruses.
Another mechanism of variability is gene recombination. Such a process takes place during sexual reproduction in higher organisms. In this case, there is no change in the total amount of genetic information.
Another mechanism of variability was discovered only in the 1950s. This is a non-classical recombination of genes, in which there is a general increase in the amount of genetic information due to the inclusion of new genetic elements in the cell genome. Most often, these elements are introduced into the cell by viruses.
2. Cellular level. Today, science has reliably established that the smallest independent unit of the structure, functioning and development of a living organism is a cell, which is an elementary biological system capable of self-renewal, self-reproduction and development. Cytology is a science that studies a living cell, its structure, functioning as an elementary living system, explores the functions of individual cellular components, the process of cell reproduction, adaptation to environmental conditions, etc. Cytology also studies the features of specialized cells, the formation of their special functions and the development of specific cellular structures . Thus, modern cytology has been called cell physiology.
A significant advance in the study of cells occurred at the beginning of the 19th century, when the cell nucleus was discovered and described. Based on these studies, the cellular theory was created, which became the greatest event in biology in the 19th century. It was this theory that served as the foundation for the development of embryology, physiology, and the theory of evolution.
The most important part of all cells is the nucleus, which stores and reproduces genetic information, regulates the metabolic processes in the cell.
All cells are divided into two groups:
Prokaryotes - cells lacking a nucleus
eukaryotes are cells that contain nuclei
Studying a living cell, scientists drew attention to the existence of two main types of its nutrition, which allowed all organisms to be divided into two types:
Autotrophic - produce their own nutrients
· Heterotrophic - can not do without organic food.
Later, such important factors as the ability of organisms to synthesize the necessary substances (vitamins, hormones), provide themselves with energy, dependence on the ecological environment, etc. were clarified. Thus, the complex and differentiated nature of the relationships indicates the need for a systematic approach to the study of life at the ontogenetic level. .
3. Ontogenetic level. multicellular organisms. This level arose as a result of the formation of living organisms. The basic unit of life is an individual, and the elementary phenomenon is ontogenesis. Physiology deals with the study of the functioning and development of multicellular living organisms. This science considers the mechanisms of action of various functions of a living organism, their relationship with each other, regulation and adaptation to the external environment, origin and formation in the process of evolution and individual development of an individual. In fact, this is the process of ontogenesis - the development of the organism from birth to death. In this case, growth, movement of individual structures, differentiation and complication of the organism occur.
All multicellular organisms are composed of organs and tissues. Tissues are a group of physically connected cells and intercellular substances to perform certain functions. Their study is the subject of histology.
Organs are relatively large functional units that combine various tissues into certain physiological complexes. In turn, organs are part of larger units - body systems. Among them are the nervous, digestive, cardiovascular, respiratory and other systems. Only animals have internal organs.
4. Population-biocenotic level. This is a supra-organismal level of life, the basic unit of which is the population. In contrast to a population, a species is a collection of individuals that are similar in structure and physiological properties, have a common origin, and can freely interbreed and produce fertile offspring. A species exists only through populations representing genetically open systems. Population biology is the study of populations.
The term "population" was introduced by one of the founders of genetics, V. Johansen, who called it a genetically heterogeneous set of organisms. Later, the population began to be considered an integral system, continuously interacting with the environment. It is the populations that are the real systems through which the species of living organisms exist.
Populations are genetically open systems, since the isolation of populations is not absolute and the exchange of genetic information is not possible from time to time. It is populations that act as elementary units of evolution; changes in their gene pool lead to the emergence of new species.
Populations capable of independent existence and transformation are united in the aggregate of the next supraorganismal level - biocenoses. Biocenosis - a set of populations living in a certain area.
The biocenosis is a system closed to foreign populations, for its constituent populations it is an open system.
5. Biogeocetonic level. Biogeocenosis is a stable system that can exist for a long time. Equilibrium in a living system is dynamic, i.e. represents a constant movement around a certain point of stability. For its stable functioning, it is necessary to have feedback between its control and executing subsystems. This way of maintaining a dynamic balance between various elements of biogeocenosis, caused by the mass reproduction of some species and the reduction or disappearance of others, leading to a change in the quality of the environment, is called an ecological disaster.
Biogeocenosis is an integral self-regulating system in which several types of subsystems are distinguished. Primary systems are producers that directly process inanimate matter; consumers - a secondary level at which matter and energy are obtained through the use of producers; then come second-order consumers. There are also scavengers and decomposers.
The cycle of substances passes through these levels in the biogeocenosis: life is involved in the use, processing and restoration of various structures. In biogeocenosis - a unidirectional energy flow. This makes it an open system, continuously connected with neighboring biogeocenoses.
Self-regulation of biogeocens proceeds the more successfully, the more diverse the number of its constituent elements. The stability of biogeocenoses also depends on the diversity of its components. The loss of one or more components can lead to an irreversible imbalance and its death as an integral system.
6. Biosphere level. This is the highest level of life organization, covering all the phenomena of life on our planet. The biosphere is the living substance of the planet and the environment transformed by it. Biological metabolism is a factor that unites all other levels of life organization into one biosphere. At this level, there is a circulation of substances and the transformation of energy associated with the vital activity of all living organisms living on Earth. Thus, the biosphere is a single ecological system. The study of the functioning of this system, its structure and functions is the most important task of biology at this level of life. Ecology, biocenology and biogeochemistry are engaged in the study of these problems.
The development of the doctrine of the biosphere is inextricably linked with the name of the outstanding Russian scientist V.I. Vernadsky. It was he who managed to prove the connection of the organic world of our planet, acting as a single inseparable whole, with geological processes on Earth. Vernadsky discovered and studied the biogeochemical functions of living matter.
Thanks to the biogenic migration of atoms, living matter performs its geochemical functions. Modern science identifies five geochemical functions that living matter performs.
1. The concentration function is expressed in the accumulation of certain chemical elements inside living organisms due to their activity. The result of this was the emergence of mineral reserves.
2. The transport function is closely related to the first function, since living organisms carry the chemical elements they need, which then accumulate in their habitats.
3. The energy function provides energy flows penetrating the biosphere, which makes it possible to carry out all the biogeochemical functions of living matter.
4. Destructive function - the function of destruction and processing of organic remains, during this process, the substances accumulated by organisms are returned to natural cycles, there is a cycle of substances in nature.
5. Average-forming function - transformation of the environment under the influence of living matter. The entire modern appearance of the Earth - the composition of the atmosphere, hydrosphere, upper layer of the lithosphere; most of the minerals; climate is the result of the action of Life.
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.