Sciences that study life at the molecular level. Levels of organization of living matter

Properties of living organisms

1. Metabolism and energy from environment(the main sign of the living).

2. Irritability(ability to respond to influences).

3. reproduction(self-reproduction).

Levels of organization of living matter

1. Molecular is the level of difficulty organic matter- proteins and nucleic acids. At this level, there chemical reactions of metabolism(glycolysis, crossing over, etc.), but the molecules themselves cannot yet be considered alive.

2. Cellular. At this level there is life, because a cell is the smallest unit that has all the properties of a living thing.

3. Organ-tissue- characteristic only for multicellular organisms.

4. Organismic- due to neuro-humoral regulation and metabolism at this level, homeostasis, i.e. maintaining the constancy of the internal environment of the body.

5. Population-species. At this level there is evolution, i.e. change in organisms associated with their adaptation to the environment under the influence of natural selection. The smallest unit of evolution is the population.

6. Biogeocenotic(set of populations different types connected with each other and the surrounding inanimate nature). At this level there is

• the circulation of matter and the transformation of energy, as well as
• self-regulation, due to which the stability of ecosystems and biogeocenoses is maintained.

7. Biospheric. At this level there is

• global circulation substances and energy conversion, as well as
• interaction between living and non-living matter planets.

Choose two correct answers from five and write down the numbers under which they are indicated. At what levels of organization of living things do they study the significance of photosynthesis in nature?
1) biospheric
2) cellular
3) biogeocenotic
4) molecular
5) tissue-organ

Answer

Choose the one most correct option. What level of organization of wildlife is a set of populations of different species, interconnected and the surrounding inanimate nature
1) organismic
2) population-species
3) biogeocenotic
4) biosphere

Answer

Choose one, the most correct option. Gene mutations occur at the level of organization of the living
1) organism
2) cellular
3) species
4) molecular

Answer

Choose one, the most correct option. The elementary structure at the level of which the action of natural selection is manifested in nature
1) organism
2) biocenosis
3) view
4) population

Answer

Choose two correct answers from five and write down the numbers under which they are indicated. What features are similar for living and non-living objects of nature?
1) cellular structure
2) change in body temperature
3) heredity
4) irritability
5) movement in space

Answer

Choose two correct answers from five and write down the numbers under which they are indicated. At what levels of organization of living things do they study the features of photosynthesis reactions in higher plants?
1) biospheric
2) cellular
3) population-species
4) molecular
5) ecosystem

Answer

Below is a list of concepts. All of them, except for two, are levels of organization of the living. Find two concepts that “drop out” of the general series, and write down the numbers under which they are indicated.
1) biosphere
2) gene
3) population-species
4) biogeocenotic
5) biogenic

Answer

1. Establish the sequence in which the levels of organization of the living are located. Write down the corresponding sequence of numbers.
1) population
2) cellular
3) specific
4) biogeocenotic
5) molecular genetic
6) organismic

Answer

2. Establish a sequence of complication of the levels of organization of the living. Write down the corresponding sequence of numbers.
1) biosphere
2) cellular
3) biogeocenotic
4) organismic
5) population-species

Answer

3. Position in right order levels of organization of life, starting with the smallest.
1) biocenosis
2) population
3) neuron
4) multicellular organism
5) biosphere

Answer

1. Choose two correct answers from five and write down the numbers under which they are indicated. The cellular level of organization is the same as the organism level.
1) bacteriophages
2) amoeba dysentery
3) polio virus
4) wild rabbit
5) green euglena

Answer

2. Choose two correct answers out of five and write down the numbers under which they are indicated in the table. At the same time, they correspond to the cellular and organismic levels of life organization.
1) freshwater hydra
2) spirogyra
3) ulotrix
4) amoeba dysentery
5) cyanobacteria

Answer

3. Choose two correct answers. Which organisms have the same cellular and organismal levels of life?
1) sulfur bacterium
2) penicillium
3) chlamydomonas
4) wheat
5) hydra

Answer

Choose two correct answers from five and write down the numbers under which they are indicated. One amoeba ordinary at the same time is on:
1) Molecular level of organization of life
2) Population-species level of life organization
3) Cellular level of life organization
4) Tissue level of life organization
5) Organismic level of organization of life

Answer

1. Choose two correct answers from five and write down the numbers under which they are indicated. Living is different from non-living
1) the ability to change the properties of an object under the influence of the environment
2) the ability to participate in the cycle of substances
3) the ability to reproduce their own kind
4) change the size of the object under the influence of the environment
5) the ability to change the properties of other objects

Answer

2. Choose two correct answers out of five and write down the numbers under which they are indicated. What characteristics are unique to living matter?
1) growth
2) movement
3) self-reproduction
4) rhythm
5) heredity

Answer

3. Choose two correct answers from five and write down the numbers under which they are indicated. All living organisms are characterized
1) the formation of organic substances from inorganic
2) absorption from the soil of minerals dissolved in water
3) active movement in space
4) breathing, nutrition, reproduction
5) irritability

Answer

4. Choose two correct answers from five and write down the numbers under which they are indicated. What features are characteristic only for living systems?
1) the ability to move
2) metabolism and energy
3) dependence on temperature fluctuations
4) growth, development and ability to reproduce
5) stability and relatively weak variability

Answer

Establish a correspondence between the levels of organization of living things and their characteristics and phenomena: 1) biocenotic, 2) biospheric. Write down the numbers 1 and 2 in the order corresponding to the letters.
A) processes cover the entire planet
B) symbiosis
C) interspecies struggle for existence
D) energy transfer from producers to consumers
D) evaporation of water
E) succession (change of natural communities)

Answer

Choose two correct answers from five and write down the numbers under which they are indicated. Ontogeny, metabolism, homeostasis, reproduction occur at ... levels of organization.
1) cellular
2) molecular
3) organismic
4) organ
5) fabric

Answer

Choose two correct answers out of five and write down the numbers under which they are indicated in the table. At the population-species level of life organization there are
1) fish of Lake Baikal
2) birds of the Arctic
3) Amur tigers of the Primorsky Territory of Russia
4) city sparrows of the Park of Culture and Leisure
5) tits of Europe

Answer

Choose two correct answers out of five and write down the numbers under which they are indicated in the table. Which of the levels of life organization are supraspecific?
1) population-species
2) organoid-cellular
3) biogeocenotic
4) biosphere
5) molecular genetic

Answer

Choose two correct answers from five and write down the numbers under which they are indicated. The cellular level of life organization corresponds to
1) chlamydomonas
2) sulfur bacterium
3) bacteriophage
4) kelp
5) lichen

Answer

Choose two options. The energy exchange common amoeba occurs at the level of organization of living
1) cellular
2) biospheric
3) organismic
4) biogeocenotic
5) population-species

Answer

Choose two correct answers from five and write down the numbers under which they are indicated. At what level of organization do such processes as irritability and metabolism take place?
1) population-species
2) organismic
3) molecular genetic
4) biogeocenotic
5) cellular

Answer

© D.V. Pozdnyakov, 2009-2019

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 physicochemical 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 life 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 nonspecific

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.

On 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" 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 molecules of proteins and phospholipids 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. The tissues arose during 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. Specific feature organism level lies in the fact that at this level, the decoding and implementation of genetic information, the creation of structural and functional features inherent in organisms of this 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 factors environment. 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.

ISSUES FOR DISCUSSION

1. What is the general methodological approach to understanding the essence of life?

2. Is it possible to define the essence of life, if so, what is its definition?

3. Is it possible to raise the question of the substratum of life?

4. Name the properties of the living. Indicate which of these properties are characteristic of non-living things and which are only for living things?

5. What is the significance for biology of the division of the living into levels in general and for medicine in particular?

6. What common features characterize different levels of organization of living things?

7. What is the significance of studying the problems described in this chapter for the medical student?

8. Why are nucleoproteins considered the substrate of life and under what conditions do they fulfill this role?

9. What are the properties of "dead" and "alive"?

10. Do nucleoproteins isolated from cells have the properties of a life substrate?

By the 1960s in biology there is an idea of ​​the levels organization of the living as a concrete expression of an increasingly complex orderlinessorganic world. Life on Earth is represented by organisms of a kindbuildings belonging to certain systematic groups (type), as well ascommunities of varying complexity (biogeocenosis, biosphere). In turn, organismscharacterized by organ, tissue, cellular and molecular organization.Each organism, on the one hand, consists of specialized subordinateorganization systems (organs, tissues, etc.), on the other hand, is itselfrelatively isolated unit in the composition of supraorganismal biologicalsystems (species, biogeocenoses and the biosphere as a whole). Levels of organization alivematter are presented in fig. one

Fig.1. Levels of organization of the living

On all of them, such properties of life as discreteness and integrity are manifested. The body is made up of various components- organs, but at the same time, thanks to their interaction, it is integral. The species is also an integral system, although it is formed by separate units - individuals, however, their interaction maintains the integrity of the species. The existence of life at all levels is provided by the structure of the lowest rank. For example, the nature of the cellular level of organization is determined by the subcellular and molecular levels; organismic - organ; tissue, cellular; species - organismic, etc. It should be noted the great similarity of units of organization at the lower levels and the ever-increasing difference at higher levels(Table 1).

Table 1

Characteristics of the levels of organization of the living

All Live nature is a collection of biological systems different levels organization and different subordination.
The level of organization of living matter is understood as the functional place that a given biological structure occupies in common system organization of nature.

The level of organization of living matter is a set of quantitative and qualitative parameters of a certain biological system(cell, organism, population, etc.), which determine the conditions and boundaries of its existence.

There are several levels of organization of living systems, which reflect subordination, hierarchy structural organization life.

• Molecular (molecular-genetic) level represented by individual biopolymers (DNA, RNA, proteins, lipids, carbohydrates and other compounds); at this level of life, phenomena associated with changes (mutations) and reproduction are studied genetic material, metabolism. This is the science of molecular biology.
• Cellularlevel- the level at which life exists in the form of a cell - the structural and functional unit of life, is studied by cytology. At this level, processes such as metabolism and energy, information exchange, reproduction, photosynthesis, transmission of nerve impulses, and many others are studied.

The cell is the structural unit of all living things.

• tissue level studying histology.

Tissue is a combination of intercellular substance and cells similar in structure, origin and functions.

• Organlevel. An organ contains several tissues.
• Organismiclevel- the independent existence of a single individual - a unicellular or multicellular organism is studied, for example, by physiology and autecology (ecology of individuals). An individual as an integral organism is an elementary unit of life. Life in nature does not exist in any other form.

An organism is a real carrier of life, characterized by all its properties.

• population-specieslevel- level, which is represented by a group of individuals of the same species - population; it is in the population that elementary evolutionary processes (accumulation, manifestation, and selection of mutations) take place. This level of organization is studied by such sciences as de-ecology (or population ecology), evolutionary doctrine.

A population is a collection of individuals of the same species that exist for a long time in a certain area, interbreed freely and are relatively isolated from other individuals of the same species.

• Biogeocenoticlevel- represented by communities (ecosystems) consisting of different populations and their habitats. This level of organization is studied by biocenology or synecology (community ecology).

Biogeocenosis is a combination of all species with varying complexity of organization and all factors of their habitat.

• biosphericlevel- level representing the totality of all biogeocenoses. In the biosphere, the circulation of substances and the transformation of energy with the participation of organisms take place.

There are such levels of organization of living matter - levels of biological organization: molecular, cellular, tissue, organ, organism, population-species and ecosystem.

Molecular level of organization- this is the level of functioning of biological macromolecules - biopolymers: nucleic acids, proteins, polysaccharides, lipids, steroids. From this level, the most important life processes begin: metabolism, energy conversion, transmission of hereditary information. This level is studied: biochemistry, molecular genetics, molecular biology, genetics, biophysics.

This is the level of cells (cells of bacteria, cyanobacteria, unicellular animals and algae, unicellular fungi, cells of multicellular organisms). A cell is a structural unit of the living, a functional unit, a unit of development. This level is studied by cytology, cytochemistry, cytogenetics, microbiology.

Tissue level of organization- This is the level at which the structure and functioning of tissues is studied. This level is studied by histology and histochemistry.

Organ level of organization- This is the level of organs of multicellular organisms. Anatomy, physiology, embryology study this level.

Organismal level of organization- this is the level of unicellular, colonial and multicellular organisms. The specificity of the organismic level is that at this level the decoding and implementation of genetic information takes place, the formation of features inherent in individuals of a given species. This level is studied by morphology (anatomy and embryology), physiology, genetics, paleontology.

Population-species level is the level of aggregates of individuals - populations and species. This level is studied by systematics, taxonomy, ecology, biogeography, population genetics. At this level, the genetic and ecological characteristics of populations, elementary evolutionary factors and their impact on the gene pool (microevolution), the problem of species conservation are studied.

Ecosystem level of organization- this is the level of microecosystems, mesoecosystems, macroecosystems. At this level, types of nutrition, types of relationships between organisms and populations in an ecosystem, population size, population dynamics, population density, ecosystem productivity, successions are studied. This level studies ecology.

Allocate also biospheric level of organization living matter. The biosphere is a giant ecosystem that occupies part of the geographic envelope of the Earth. This is a mega ecosystem. In the biosphere, there is a cycle of substances and chemical elements, as well as the conversion of solar energy.