The ability of living organisms to change their size over time. The ability of living organisms to respond to external influences is an innate property and a protective reaction. What are the properties of living organisms

Identification of the general properties of living organisms will make it possible to clearly distinguish living from non-living. There is no exact definition of what life or a living organism is, so a living thing is identified by a set of its properties, or characteristics.

Unlike bodies of inanimate nature, living organisms are distinguished by the complexity of their structure and functionality. But if we consider each property separately, then some of them in one form or another can be observed in inanimate nature. For example, crystals can also grow. That is why the totality of properties of living organisms is so important.

At first glance, the observed diversity of organisms creates difficulties in identifying their common properties and characteristics. However, as the biological sciences developed historically, many general patterns of life observed in completely different groups of organisms became apparent.

In addition to the properties of living things listed below, they are also often distinguished unity of chemical composition(similarity in all organisms and differences in the ratios of elements between living and nonliving), discreteness(organisms consist of cells, species consist of individuals, etc.), participation in the process of evolution, interaction of organisms with each other, mobility, rhythm and etc.

There is no definitive list of signs of living things; this is partly a philosophical question. Often, by highlighting one property, the second becomes its consequence. There are signs of living things, consisting of a number of others. In addition, the properties of living things are closely interconnected, and this interdependence together gives such a unique natural phenomenon as life.

Metabolism is the main property of living things

All living organisms exchange substances with the environment: certain substances enter the body from the environment, others are released into the environment from the body. This characterizes the organism as an open system (also the flow of energy and information through the system). The presence of selective metabolism indicates that the organism is alive.

Metabolism in the body itself includes two opposite, but interconnected and balanced processes - assimilation (anabolism) and dissimilation (catabolism). Each of them consists of numerous chemical reactions, combined and ordered into cycles and chains of transformation of one substance into another.

As a result of assimilation, the structures of the body are formed and renewed due to the synthesis of the necessary complex organic substances from simpler organic, as well as inorganic substances. As a result of dissimilation, organic substances are broken down, and simpler substances necessary for assimilation are formed, and energy is stored in ATP molecules.

Metabolism requires an influx of substances from the outside, and a number of dissimilation products do not find use in the body and must be removed from it.

All living organisms are in one way or another eat. Food serves as a source of necessary substances and energy. Plants eat through the process of photosynthesis. Animals and fungi absorb organic substances from other organisms, after which they break them down into simpler components from which they synthesize their own substances.

It is common for living organisms allocation a number of substances (in animals these are mainly products of the breakdown of proteins - nitrogenous compounds), which are the end products of metabolism.

An example of an assimilation process is the synthesis of protein from amino acids. An example of dissimilation is the oxidation of organic matter with the participation of oxygen, resulting in the formation of carbon dioxide (CO 2) and water, which are removed from the body (water can be used).

Energy dependence of living things

To carry out vital processes, organisms need an influx of energy. In heterotrophic organisms, it comes with food, that is, their metabolism and energy flow are connected. When nutrients are broken down, energy is released, stored in other substances, and some is dissipated as heat.

Plants are autotrophs and receive their initial energy from the Sun (they capture its radiation). This energy goes to the synthesis of primary organic substances (in which it is stored) from inorganic ones. This does not mean that chemical reactions of decay (dissimilation) of organic substances do not occur in plants to produce energy. However, plants do not receive organic matter from outside through nutrition. She is completely “their own” among them.

Energy is used to support the orderliness and structure of living organisms, which is important for the occurrence of numerous chemical reactions in them. Resistance to entropy is an important property of living things.

Breath- this is a process characteristic of living organisms, as a result of which high-energy compounds are broken down. The energy released during this process is stored in ATP.

In inanimate nature (when processes are left to chance), the structure of systems is sooner or later lost. In this case, one or another equilibrium is established (for example, a hot body gives off heat to others, the temperature of the bodies is equalized). The less order, the greater the entropy. If the system is closed and processes occur in it that do not balance each other, then entropy increases (the second law of thermodynamics). Living organisms have the property of reducing entropy by maintaining internal structure due to the influx of energy from the outside.

Heredity and variability as a property of living things

The basis for the self-renewal of the structures of living organisms, as well as the reproduction (self-reproduction) of organisms, is heredity, which is associated with the characteristics of DNA molecules. At the same time, changes may appear in DNA that lead to variability in organisms and provide the possibility of the process of evolution. Thus, living organisms have genetic (biological) information, which can also be designated as the main and exclusive feature of living things.

Despite the ability for self-renewal, it is not eternal in organisms. The lifespan of an individual is limited. However, the living remains immortal due to the process reproduction, which can be either sexual or asexual. In this case, the characteristics of parents are inherited by passing their DNA to their descendants.

Biological information is recorded using a special genetic code, which is universal for all organisms on Earth, which can indicate the unity of the origin of living things.

The genetic code is stored and implemented in biological polymers: DNA, RNA, proteins. Such complex molecules are also a feature of living things.

Information stored in DNA, when transferred to proteins, is expressed for living organisms in their properties such as genotype and phenotype. All organisms have them.

Growth and development - properties of living organisms

Growth and development are the properties of living organisms, realized in the process of their ontogenesis (individual development). Growth is an increase in body size and weight while maintaining the general structure of the body. In the process of development, the body changes, it acquires new characteristics and functionality, while others may be lost. That is, as a result of development, a new qualitative state arises. In living organisms, growth is usually accompanied by development (or development by growth). Development is directed and irreversible.

In addition to individual development, there is the historical development of life on Earth, which is accompanied by the formation of new species and the complication of life forms.

Although growth can be observed in inanimate nature (for example, in crystals or cave stalagmites), its mechanism in living organisms is different. In inanimate nature, growth occurs through the simple attachment of a substance to the outer surface. Living organisms grow due to the nutrients they take in. At the same time, it is not so much the cells themselves that are enlarged, but their number that increases.

Irritability and self-regulation

Living organisms have the property, within certain limits, to change their state depending on the conditions of both the external and internal environment. In the process of evolution, species have developed different ways of recording environmental parameters (among other things through the senses) and responding to different stimuli.

The irritability of living organisms is selective, that is, they react only to what is important for the preservation of their life.

Irritability underlies the body's self-regulation, which, in turn, has adaptive significance. Thus, when body temperature rises in mammals, the blood vessels dilate, releasing more heat into the environment. As a result, the animal's temperature normalizes.

In higher animals, many reactions to external stimuli depend on fairly complex behavior.

Biology(from the Greek words bios - life, logos - teaching) is a science that studies living organisms and natural phenomena.

The subject of biology is the diversity of living organisms inhabiting the Earth.

Properties of living nature. All living organisms have a number of common characteristics and properties that distinguish them from inanimate bodies. These are structural features, metabolism, movement, growth, reproduction, irritability, self-regulation. Let us dwell on each of the listed properties of living matter.

Highly ordered structure. Living organisms consist of chemical substances that have a higher level of organization than inanimate substances. All organisms have a certain structure plan - cellular or non-cellular (viruses).

Metabolism and energy- this is a set of processes of respiration, nutrition, excretion, through which the body receives the substances and energy it needs from the external environment, transforms and accumulates them in its body and releases waste products into the environment.

Irritability- this is the body’s response to changes in the environment, helping it adapt and survive in changing conditions. When pricked by a needle, a person withdraws his hand, and the hydra shrinks into a ball. The plants turn towards the light, and the amoeba moves away from the crystal of table salt.

Growth and development. Living organisms grow, increase in size, develop, and change due to the supply of nutrients.

Reproduction- the ability of living things to reproduce themselves. Reproduction is associated with the phenomenon of transmission of hereditary information and is the most characteristic feature of living things. The life of any organism is limited, but as a result of reproduction, living matter is “immortal.”

Movement. Organisms are capable of more or less active movement. This is one of the clearest signs of being alive. Movement occurs both within the body and at the cellular level.

Self-regulation. One of the most characteristic properties of living things is the constancy of the internal environment of the organism under changing external conditions. Body temperature, pressure, gas saturation, concentration of substances, etc. are regulated. The phenomenon of self-regulation occurs not only at the level of the whole organism, but also at the cellular level. In addition, thanks to the activity of living organisms, self-regulation is inherent in the biosphere as a whole. Self-regulation is associated with such properties of living things as heredity and variability.

Heredity- this is the ability to transmit the characteristics and properties of an organism from generation to generation during the process of reproduction.

Variability is the ability of an organism to change its characteristics when interacting with the environment.

The ability of living organisms to change their size during life is called 1. development 2. reproduction 3. variability 4. growth

What function do organelles containing chlorophyll perform in green euglena? 1. form organic substances from inorganic substances in the light 2. accumulate a supply of nutrients 3. digest captured food particles 4. remove excess water and unnecessary substances dissolved in it

Among the listed groups of invertebrate animals, they have a two-layer structure: 1. annelids 2. flatworms 3. mollusks 4. coelenterates

The nervous system of an earthworm consists of 1. the head ganglion and nerve branches 2. nerve trunks with branches 3. the peripharyngeal nerve ring and the ventral nerve cord 4. the head ganglion, the dorsal ganglion and the nerves extending from them

Highly organized invertebrate animals with a soft body covered with a shell, under which there is a mantle, are classified as 1. coelenterates 2. chordates 3. mollusks 4. flatworms

Multicellular invertebrate animals with an external skeleton made of chitin are classified as 1. coelenterates 2. mollusks 3. annelids 4. arthropods

1. 2. 3. 4. Multicellular invertebrate animals with an external skeleton made of chitin are classified as coelenterates, annelids, arthropods

What determines the adaptation of flounder to defense against enemies? 1. can swim quickly 2. secretes poisonous mucus with its skin 3. invisible against the surrounding background 4. has large and sharp teeth

Amphibious vertebrates that 1. spend their entire lives in water, reproduce in water, 2. adults can live both in water and in wet places on land 3. reproduce on land, adults live only in water 4. reproduce on land, adults individuals live far from bodies of water

What feature allows reptiles to reproduce on land? 1. high speed of movement 2. dense (leathery) egg shell 3. lack of constant body temperature 4. large number of eggs laid

The highest metabolic rate is characteristic of birds, since they 1. spend a lot of energy during flight 2. inhabit the terrestrial air habitat 3. live in different natural zones 4. feed on plant and animal foods

What change in the environment signals the fall migration of birds? 1. increase in air temperature 2. lack of food 3. increase in air humidity 4. increase in cloudiness

Which statements are true? A. Hydra stinging cells are located mainly on the tentacles. B. Mollusks are exclusively aquatic animals. 1) only A 2) only B 3) both A and B 4) neither A nor B

Establish a correspondence between the animal's characteristic and the type for which this characteristic is characteristic: for each position from the first column, select the corresponding position from the second column, indicated by a number. SIGNS TYPES A) do not have a circulatory system 1) Annelids B) have a circulatory system 2) Flatworms C) participate in the process of soil formation D) many species do not have a digestive system Write down the selected numbers in the table. A 2 B 1 C 1 D 2

The list below lists some systematic groups, indicated by letters. A) family Wolf (Canidae) B) class Mammals C) species Common Fox D) order Carnivores E) genus Foxes Establish a sequence reflecting the position of the species Common Fox in the classification of animals, starting with the smallest group. Write the letters in the correct sequence in the table. C d a g b

Read the text using the lettered words to choose from (you can change the endings). Animals whose articulated body is divided into a head, chest and abdomen (or cephalothorax and abdomen) are classified as type B. Among them there are aquatic and land animals, such as A., and arachnids, as well as B.. . , living in all habitats. Important features of animals belonging to this type are: D. . . , playing the role of an exoskeleton, and articulated limbs. Words for selection: A. Crustaceans B. Insects B. Arthropods D. Annulated E. chitinous cover E. calcareous cover Write down in the table the letters corresponding to the missing words, in the order in which they should appear in place of the gaps in the text.

Under unfavorable conditions, many protozoa, like bacteria, are able to form a protective shell called 1. spore 2. shell 3. zygote 4. cyst

What function does the contractile vacuole perform in the common amoeba? 1. capture and digestion of food 2. removal of solid undigested residues 3. release of carbon dioxide formed during the digestion process into the environment 4. removal of water along with soluble harmful substances formed in the body

In the body of the hydra, skin-muscular (integumentary muscle) cells are located mainly in (in) the intestinal cavity middle plate mesoglea outer layer of ectoderm inner layer of endoderm

The mantle in mollusks is 1. an organ of movement 2. a fold of skin located under the shell 3. a part of the body 4. a protective shell, the valves of which are tightly closed

What class of arthropods include animals whose body consists of a head, chest and abdomen; on the head there are: a pair of compound eyes, a pair of antennae, mouthparts; there are three pairs of legs on the chest, and most also have wings? 1. Insects 2. Arachnids 3. Crustaceans 4. Gastropods

Fish are animals with a body temperature that is 1. constant in both winter and summer 2. changing regardless of the ambient temperature 3. changing when the ambient temperature changes 4. constant during one season (for example, in summer)

The class of amphibians includes 1. crested newt 2. common grass snake 3. Nile crocodile 4. marsh turtle

In reptiles, unlike other vertebrates, the skin is 1. dry, covered with horny scales or scutes 2. serves as an additional respiratory organ 3. moist, covered with bone scales 4. moist, rich in glands

Among vertebrates, the most complex structure of the circulatory and nervous systems is found in 1. cartilaginous and bony fishes 2. tailed and tailless amphibians 3. aquatic reptiles 4. birds and mammals

In connection with reaching land and the appearance of lungs in amphibians, the formation of 1. a three-chambered heart 2. five parts of the brain 3. jaw apparatus 4. skin glands occurred

Which statements are true? A. With the help of the lateral line organ, the fish senses the direction and strength of the water flow, as well as the depth of immersion. B. In most birds, the sternum has a high keel crest. 1) only A 2) only B 3) both A and B 4) neither A nor B

Establish a correspondence between the typical characteristics of animals and the systematic group for which they are characteristic: for each position from the first column, select the corresponding position from the second column, indicated by a number. SIGNS OF ANIMALS SYSTEMATIC GROUPS A) the body consists of a head, chest and abdomen B) branchial respiration C) the body consists of a cephalothorax and abdomen D) tracheal respiration 1) Insects 2) Crustaceans Write down the selected numbers in the table. A 1 B 2 C 2 D 1

The list below lists some systematic groups, indicated by letters. A) B) B) D) E) class Insects species Cabbage whites order Lepidoptera genus Garden whites family Whites Establish a sequence reflecting the position of the species Cabbage whites in the classification of animals, starting with the smallest group. Write the letters in the correct sequence in the table. Bgdva

Fish are aquatic vertebrates. Their body has a streamlined shape. The pointed head gradually turns into. G. . , and then into the tail. The support of the fish's body is bone or cartilage. . V., which stretches from the head to the caudal fin. The body is covered. D. and mucus secreted by the skin. . A. . Mucus reduces friction when moving. Words for choice: A) glands B) fins C) spine D) torso E) scales E) neck

The ability of living organisms to increase their numbers is called 1. heredity 2. reproduction 3. evolution 4. fitness

If the ciliate slipper moves with the help of cilia, then Euglena green moves with the help of 1. contractile vacuole 2. pseudopods 3. flagella 4. tentacles

Among the listed groups of invertebrate animals, the most primitive nervous system (diffuse type) is found in 1. Flukes 2. Coelenterates 3. Crustaceans 4. Insects

Why can you observe a massive appearance of earthworms on the surface of the earth after rain? 1. the temperature in the worm holes decreases 2. moles, which are the enemies of the worms, become more active 3. the worms can grow unhindered 4. water displaces air from the worm holes

Of the listed animals, gastropods include 1. grape snail 2. toothless snail 3. oyster 4. octopus

Chitinous cover, heterogeneous segments united into sections (two or three), dissected limbs have 1. arthropods 2. annelids 3. mollusks 4. roundworms

The systematic character of the class, the representative of which is shown in the figure, is considered to be 1. body articulation 2. articulation of limbs 3. number of limbs 4. habitation on land

A characteristic feature of the seahorse’s adaptation to protection from enemies is 1. similarity with other fish in shape and color 2. similarity with plants in shape and color 3. the presence of glands that produce poison 4. the ability to quickly swim away from a predator

You can distinguish a viviparous lizard from a crested newt by 1. the number of limbs 2. the presence of a tail 3. skin structure 4. body temperature

The most important feature that distinguishes birds from reptiles is 1. constant body temperature 2. development on land 3. pulmonary respiration 4. closed circulatory system

In the life of warm-blooded animals, the main regulating factor of annual and seasonal rhythms is 1. the number of sunny days per year 2. the phase of the lunar cycle 3. the amount of precipitation at different times of the year 4. the duration of daylight hours throughout the year

Which statements are true? A. Some animals cross-pollinate plants. B. Hydra is a large single-celled organism. 1) only A 2) only B 3) both A and B 4) neither A nor B

Establish a correspondence between the insect and its type of development: for each position from the first column, select the corresponding position from the second column, indicated by a number. INSECT TYPES OF DEVELOPMENT A) honey bee 1) with incomplete transformation B) chafer C) Asian locust 2) with complete transformation D) green grasshopper Write down the selected numbers in the table. A 2 B 2 C 1 D 1

The list below lists some systematic groups, indicated by letters. A) family Passeriformes B) class Birds C) species Field Sparrow D) order Passeriformes E) genus Sparrows Establish a sequence reflecting the position of the field sparrow in the classification of animals, starting with the largest group (class). Write down the letters in the correct sequence bgadv in the table

The common pond snail, a representative of the gastropod class, lives in ponds, lakes and quiet creeks. The body of the common pond snail is divided into. . A., on which there are eyes, a mouth and two tentacles, a torso and a leg. The body of the mollusk is covered on top with a special fold of skin. B. . , protecting from hard. . G. . The legs of gastropods are muscular, well developed and wide. . IN. . Words to choose: Write down in the table the letters corresponding to the missing words, in the order in which they should appear in place of the gaps in the text. A) B) C) D) D) E) head mantle sole shell body tentacles

Among unicellular organisms, the following have a variable body shape: 1. green euglena 2. common amoeba 3. slipper ciliate 4. lamblia

In the freshwater hydra polyp, stinging cells are located primarily in (on) 1. tentacles 2. sole 3. endoderm 4. intestinal cavity

The habitat for the larvae of the liver fluke is 1. cow 2. pond snail 3. sheep 4. dragonfly

The body of gastropods is divided into 1. head, thorax and shell 2. head, thorax and abdomen 3. cephalothorax and abdomen 4. head, trunk and leg

Arthropods, in which three pairs of legs are attached to the thoracic region, belong to the class 1. crustaceans 2. arachnids 3. insects 4. flukes

By what criteria can you distinguish ticks from spiders? 1. all body segments are fused together 2. the body is divided into a cephalothorax and abdomen 3. have eight legs 4. no antennae

In fish, blood is saturated with oxygen in 1. ventricle of the heart 2. atrium 3. capillaries of the body 4. capillaries of the gills

Amphibians are more highly organized animals than fish, but their body temperature is 1. variable, depends on the ambient temperature 2. does not depend on the ambient temperature 3. significantly higher than the ambient temperature 4. constant, lower than the ambient temperature

Vertebrates that have dry skin with horny scales, pulmonary breathing, a heart with an incomplete septum in the ventricle, and unstable body temperature belong to class 1. Bony fish 2. Amphibians 3. Reptiles 4. Cartilaginous fish

Birds differ from reptiles by the presence of 1. a special type of body cover 2. a central nervous system 3. internal fertilization 4. two circulatory systems

The appearance of the second (lesser) circulation in animals is associated with reaching land and the emergence of a special organ: 1. swim bladder 2. lungs 3. gills 4. multi-chambered heart

Which statements are true? A. Teeth allow a bird of prey to hold its prey. B. Annelids have a long, jointed (segmented) body. 1) only A 2) only B 3) both A and B 4) neither A nor B

Establish a correspondence between different types of mollusks and their habitat: for each position from the first column, select the corresponding position from the second column, indicated by a number. TYPE OF MOLLUSK A) common toothless b) large pond snail B) naked slug D) squid Write down the selected numbers in the table A 2 B 1 C 2 D 1 HABITAT 1) aquatic 2) terrestrial aerial

The list below lists some systematic groups, indicated by letters. A) B) B) D) E) class Insects species House cricket Homoptera genus Crickets family Crickets Establish a sequence reflecting the position of the house cricket in the classification of animals, starting with the largest group (class). Write the letters in the correct sequence in the table.

Birds are higher vertebrates that have adapted to flight. Depending on the distance of movement in the post-nesting period, birds are divided into sedentary,. B. . and migratory. Sedentary birds do not travel far. D. , they remain in the nesting areas for the winter. Flying thousands of kilometers, migratory birds fly to winter in areas where there are no harsh winters. Some birds fly south alone, others join forces. E. . . The first to fly away are lenticels, orioles. . V., swifts. Words for choice: A) waterfowl B) nomadic C) swallows D) swans E) migration E) flock

Metabolism. All living organisms have the ability to extract, transform and use energy from the environment, either in the form of nutrients or in the form of solar radiation. They return decay products and converted energy in the form of heat to the external environment. That is, organisms are capable of exchanging matter and energy with the environment.

Metabolism is one of the essential criteria of life. This property is reflected in the definition of life, which was formulated by F. Engels more than a hundred years ago:

“Life is a way of existence of protein bodies, the essential point of which is the constant exchange of substances with the external environment surrounding them, and with the cessation of this metabolism, life also ceases, which leads to the decomposition of the protein.”

This definition includes two important provisions:

A) life is closely connected with protein substances;

B) an indispensable condition for life is a constant metabolism, with the cessation of which life also ceases.

The metabolism of the protein body has two sides:

Plastic metabolism (anabolism) is a set of reactions that ensure the construction of a cell and the renewal of its composition.
Energy metabolism (catabolism) is a set of reactions that provide the cell with energy.

Anabolism + catabolism = metabolism (metabolism)

Substances coming from the environment as a result of plastic metabolism are transformed into substances of a given organism, and the body of the organism is built from them. Thus, plastic exchange consists of two simultaneous processes: the continuous breakdown of substances - dissimilation and the continuous synthesis of new compounds, i.e. assimilation. The processes of dissimilation and assimilation are united and do not exist separately from each other. As a result of these processes, a living organism changes all the time, but at the same time retains its specific structure.

For assimilation, i.e. The formation of a new complex substance, in addition to the “building material” - various chemical compounds, also requires energy. This energy is provided primarily by decay processes, i.e. processes of dissimilation. In this case, complex organic compounds are broken down into simpler ones, which are oxidized to final products, usually carbon dioxide and water, releasing energy. All this happens in the process of energy metabolism - catabolism.

A living organism requires energy not only to create new body substances, but also for various types of activities: the work of muscles, glands, nerve cells, etc., in higher animals - to maintain a constant body temperature.

The greater the load on the body, and the more energy expended, the more nutrients should be supplied. People with heavy physical labor and athletes with heavy loads need enhanced nutrition. The discrepancy between the energy supplied in the form of nutrients and the energy expended by the body leads to weight gain and disease.

Metabolism ensures the stability and constancy of the chemical composition of the cell and the entire organism, and, consequently, their activity.

Dynamic systems in which chemical reactions continuously occur due to substances and energy supplied from outside, and decomposition products are removed, are called open systems.

A living organism is an open system, because it exists as long as food enters it, as well as energy from the external environment, and some metabolic products are released.

Living organisms have a built-in self-regulation system that supports vital processes and prevents the disordered decay of structures and the release of energy. This is closely related to the metabolic process.

The ability of biological systems to resist changes and maintain dynamic constancy of composition and properties is called homeostasis

Homeostasis- relative dynamic constancy of the composition and properties of the internal environment and the stability of the basic physiological functions of the body.

There are: a) physiological homeostasis- this is the genetically determined ability of the body to maintain its status in changing environmental conditions (in mammals - the ability to maintain constant osmotic pressure in cells and blood pH);

b) developmental homeostasis - This is the genetically determined ability of the body to change individual reactions in such a way that the functions of the body are generally preserved. (In a person, when one kidney is removed, the remaining one performs double the load)

2.2 Self-reproduction ability- this is the second mandatory property of living things.

The lifespan of all living systems, from molecular structures (viruses, prions) to highly organized multicellular organisms, is limited.

Self-reproduction occurs at all levels of organization of living matter - from macromolecules to the organism. Thanks to this property, cellular structures, cells and organisms are similar in structure to their predecessors.

Self-reproduction is based on the formation of new molecules and structures based on the information contained in the DNA nucleic acid. Self-reproduction is closely related to the phenomenon of heredity: any living creature gives birth to its own kind.

The material basis of genetic programs are nucleic acids: DNA RNA protein

Protein is a functional executive mechanism that is regulated by nucleic acid. This corresponds to one of the modern definitions of life, given in 1965 by the Soviet scientist M.V. Volkenshtein: “Living bodies that exist on Earth are open, self-regulating and self-reproducing systems built from biopolymers - proteins and nucleic acids.”

2.3 Variability- This is a property opposite to heredity. It is associated with the acquisition of new characteristics and properties by organisms. Variation is based on mutations - a violation of the process of self-reproduction of DNA. Variation creates material for natural selection.

2.4 The property of living organisms is the ability for historical development and change from simple to complex. This process is called evolution. As a result of evolution, a whole variety of living organisms arose, adapted to certain conditions of existence.

Some researchers also include the following as the main properties of living organisms: a) unity of chemical composition(98% - C, N, O, H);

b) complexity and high degree of organization, i.e. complicated internal structure, but living organisms formed by one molecule have now been discovered - prions - proteins.

2.5 Levels of organization of living matter

Living nature is characterized by different levels of organization of its structures, between which there is a complex subordination.

Life at each level is studied by the corresponding branches of biology. For example, viruses - virology, plants - botany, etc.

Currently, the following levels of organization of living matter are distinguished.

The lowest, most ancient level - molecular, or level of molecular structures.
Any, even the most complex, living system manifests itself at the level of functioning of biological molecules: nucleic acids, proteins, polysaccharides and other organic substances. From this level, the most important processes of the body’s life begin: metabolism, energy conversion, transmission of hereditary information. At this level there is a boundary between living and nonliving.
Cellular level. The cell is a structural and functional unit, as well as a unit of reproduction and development of all living organisms living on Earth. There are no non-cellular forms of life, and the existence of viruses only confirms this rule, since they can manifest their properties of living systems only in cells.
Tissue level characteristic of multicellular organisms. Tissue is a collection of cells similar in structure, connected by performing common functions.
Organ level. In most living organisms, an organ is a structural and functional combination of several types of tissue. For example, the skin, as an organ, includes epithelium and connective tissue, which together perform a number of functions, among which the most significant is protective.
Sometimes levels 3 and 4 are combined into one - the organ-tissue level, or the level of the whole organism.
Organismic level. Multicellular organisms represent a whole system of organs that are strictly specialized in the functions they perform. At the organismal level, processes and phenomena occurring in an individual are studied - the mechanisms of coordinated operation of its organs and systems, as well as the role of various organs in the life of the organism, adaptive changes and behavior of organisms in various environmental conditions.
Population-species level. A set of organisms of the same species, united by a common habitat, creates a population as a system of supraorganismal order. In this system, the simplest evolutionary transformations are carried out.
View- a set of populations of individuals with hereditary similarity of morphological, physiological and biochemical characteristics, freely interbreeding and producing fertile offspring, adapted to certain living conditions and occupying a certain niche in nature - habitat.
Population(from the Latin populus - people, population) is a collection of individuals of one species that occupies a certain space for a long time and reproduces itself over a large number of generations.
If the lifespan of any living organism is determined genetically, and they inevitably die after exhausting the programmed possibilities of their development, then the population is capable of developing for a relatively long time under suitable environmental conditions. As a result, evolutionary changes are possible.
7 Level of biogeocenoses.
Biogeocenosis is a collection of organisms of different species and varying complexity of organization with all environmental factors. Those. this is a community of all types of living beings inhabiting a particular territory or water area. At this level, the laws of interspecies relations operate.
At this level, the relationship between the organism and the environment, the migration of living matter, the paths and patterns of energy circulation, etc. are studied.
8 Biosphere. This is the highest level of organization of living matter on our planet. The biosphere is the totality of all living things inhabiting the Earth.
Thus, living nature is a complexly organized hierarchical system. The laws characteristic of higher levels of organization of the living world do not exclude the action of laws characteristic of lower levels.
General biology studies the laws characteristic of all levels of life organization.

Living systems have common characteristics:
1. unity of chemical composition testifies to the unity and connection of living and nonliving matter.

Example:

living organisms contain the same chemical elements as inanimate objects, but in different quantitative ratios (i.e. living organisms have the ability to selectively accumulate and absorb elements). More than \(90\)% of the chemical composition is accounted for by four elements: C, O, N, H, which are involved in the formation of complex organic molecules (proteins, nucleic acids, carbohydrates, lipids).

2. Cellular structure (Unity of structural organization). All organisms existing on Earth are made up of cells. There is no life outside the cell.
3. Metabolism (Openness of living systems). All living organisms are “open systems”.

System openness- a property of all living systems associated with the constant supply of energy from the outside and the removal of waste products (an organism is alive while it exchanges substances and energy with the environment).

Metabolism is a set of biochemical transformations occurring in the body and other biosystems.

Metabolism consists of two interrelated processes: the synthesis of organic substances (assimilation) in the body (due to external energy sources - light and food) and the process of decomposition of complex organic substances (dissimilation) with the release of energy, which is then consumed by the body. Metabolism ensures the constancy of the chemical composition in continuously changing environmental conditions.
4. Self-reproduction (Reproduction)- the ability of living systems to reproduce their own kind. The ability to self-reproduce is the most important property of all living organisms. It is based on the process of doubling DNA molecules followed by cell division.
5. Self-regulation (Homeostasis)- maintaining the constancy of the internal environment of the body in continuously changing environmental conditions. Any living organism ensures the maintenance of homeostasis (constancy of the internal environment of the body). Persistent disruption of homeostasis leads to the death of the body.
6. Development and growth. The development of living things is represented by the individual development of the organism (ontogenesis) and the historical development of living nature (phylogeny).

In the process of individual development, the individual properties of the organism gradually and consistently manifest themselves and its growth occurs (all living organisms grow during their lives).
The result of historical development is a general progressive complication of life and the entire diversity of living organisms on Earth. Development refers to both individual development and historical development.

7. Irritability- the body’s ability to selectively respond to external and internal stimuli (reflexes in animals; tropisms, taxis and nasties in plants).
8. Heredity and variability represent factors of evolution, since thanks to them material for selection arises.

Variability- the ability of organisms to acquire new characteristics and properties as a result of the influence of the external environment and/or changes in the hereditary apparatus (DNA molecules).
Heredity- the ability of an organism to transmit its characteristics to subsequent generations.

9. Ability to adapt- in the process of historical development and under the influence of natural selection, organisms acquire adaptations to environmental conditions (adaptation). Organisms that do not have the necessary adaptations die out.
10. Integrity (continuity) And discreteness (discontinuity). Life is holistic and at the same time discrete. This pattern is inherent in both structure and function.

Any organism is an integral system, which at the same time consists of discrete units - cellular structures, cells, tissues, organs, organ systems. The organic world is integral, since all organisms and the processes occurring in it are interconnected. At the same time, it is discrete, since it consists of individual organisms.

Some of the properties listed above may also be inherent in inanimate nature.

Example:

Living organisms are characterized by growth, but crystals also grow! Although this growth does not have those qualitative and quantitative parameters that are inherent in the growth of living things.

Example:

A burning candle is characterized by processes of exchange and transformation of energy, but it is not capable of self-regulation and self-reproduction.