- an integral system of components that perform a specific function in living systems. Biological systems include complex systems of different levels of organization: biological macromolecules, subcellular organelles, cells, organs, organisms, populations.
Signs of biological systems
– criteria that distinguish biological systems from objects inanimate nature:
1. Unity chemical composition . The composition of living organisms includes the same chemical elements as in objects of inanimate nature. However, the ratio of various elements in living and non-living is not the same. In inanimate nature, the most common elements are silicon, iron, magnesium, aluminum, and oxygen. In living organisms, 98% of the elemental (atomic) composition is accounted for by only four elements: carbon, oxygen, nitrogen and hydrogen.
2. Metabolism.
All living organisms are capable of exchanging substances with the environment. They absorb nutrients from the environment and excrete waste products. In inanimate nature, there is also an exchange of substances, however, with a non-biological cycle, they are simply transferred from one place to another or change their state of aggregation: for example, washing away the soil, turning water into steam or ice, etc. In living organisms, the metabolism has a qualitatively different level. In the cycle organic matter the most significant are the processes of synthesis and decay (assimilation and dissimilation - see below), as a result of which complex substances break down into simpler ones and the energy necessary for the reactions of synthesis of new complex substances is released.
Metabolism ensures the relative constancy of the chemical composition of all parts of the body and, as a result, the constancy of their functioning in continuously changing environmental conditions.
3. self-reproduction (reproduction, reproduction) - the property of organisms to reproduce their own kind. The process of self-reproduction is carried out at almost all levels of life. The existence of each individual biological system is limited in time, so the maintenance of life is associated with self-reproduction. Self-reproduction is based on the formation of new molecules and structures, due to the information contained in the nucleic acid - DNA, which is located in the parent cells.
4. Heredity - the ability of organisms to transmit their characteristics, properties and features of development from generation to generation. Heredity is ensured by the stability of DNA and the reproduction of its chemical structure with high accuracy. The material structures of heredity transmitted from parents to descendants are chromosomes and genes.
5. Variability- the ability of organisms to acquire new features and properties; it is based on changes in the material structures of heredity. This property is, as it were, the opposite of heredity, but at the same time is closely connected with it. Variability provides a variety of material for the selection of individuals most adapted to specific conditions of existence, which, in turn, leads to the emergence of new forms of life, new types of organisms.
6. Growth and development.
The ability to develop is a universal property of matter. Development is understood as an irreversible directed regular change in objects of animate and inanimate nature. As a result of development, a new qualitative state of the object arises, its composition or structure changes. The development of a living form of matter is represented by individual development ( ontogeny) and historical development ( phylogenesis). The phylogeny of the entire organic world is called evolution.
During ontogenesis, the individual properties of organisms gradually and consistently manifest themselves. This is based on the phased implementation of hereditary programs. Individual development is often accompanied by growth - an increase in the linear dimensions and mass of the entire individual and its individual organs due to an increase in the size and number of cells.
Historical development is accompanied by the formation of new species and the progressive complication of life. As a result of evolution, all the diversity of living organisms on Earth has arisen.
7. Irritability
- These are specific selective responses of organisms to changes in the environment. Any change in the conditions surrounding the organism is an irritation in relation to it, and its response is a manifestation of irritability. By responding to environmental factors, organisms interact with it and adapt to it, which helps them survive.
The reactions of multicellular animals to stimuli, carried out and controlled by the central nervous system, are called reflexes. Organisms that do not have nervous system, are devoid of reflexes, and their reactions are expressed in a change in the nature of movement ( taxis) or growth ( tropisms).
8. discreteness
(from lat. discretus- divided). Any biological system consists of separate isolated, that is, isolated or delimited in space, but nevertheless, closely connected and interacting with each other, forming a structural and functional unity. So, any individual consists of individual cells with their special properties, and organelles and other intracellular formations are also discretely represented in the cells.
The discreteness of the structure of the body is the basis of its structural order. It creates the possibility of constant self-renewal of the system by replacing worn-out structural elements without stopping the functioning of the entire system as a whole.
9. Self-regulation(auto-regulation)- the ability of living organisms to maintain the constancy of their chemical composition and the intensity of physiological processes ( homeostasis). Self-regulation is carried out due to the activity of the nervous, endocrine and some other regulatory systems. The signal for turning on one or another regulatory system can be a change in the concentration of a substance or the state of a system.
10. Rhythm
- a property inherent in both animate and inanimate nature. It is due to various cosmic and planetary causes: the rotation of the Earth around the Sun and around its axis, the phases of the Moon, etc.
Rhythm is manifested in periodic changes in the intensity of physiological functions and shaping processes at certain equal intervals of time. The daily rhythms of sleep and wakefulness in humans, the seasonal rhythms of activity and hibernation in some mammals, and many others are well known. Rhythm is aimed at coordinating body functions with periodically changing living conditions.
11. Energy dependence. Biological systems are "open" to energy input. By "open" they mean dynamic, i.e. systems that are not at rest, stable only under the condition of continuous access to them by substances and energy from the outside. Living organisms exist as long as they receive energy and substances from the environment in the form of food. In most cases, organisms use the energy of the Sun: some directly are photoautotrophs(green plants and cyanobacteria), others indirectly, in the form of organic substances of the food consumed, are heterotrophs(animals, fungi and bacteria).
Introduction.
1. The subject of biology. Definition of life. Signs of living matter.
2. General properties of living organisms.
3. The concept of homeostasis.
4. Characteristics of the levels of organization of living nature.
5. Living organism as a system.
The subject of biology. Definition of life. Signs of living matter.
Biology(from the Greek bios-life, logos-concept, teaching) - a science that studies living organisms. The development of this science followed the path of studying the most elementary forms of the existence of matter. This applies to both living and non-living things. With this approach, they try to learn the laws of the living, studying its separate parts instead of a single whole, i.e. study the elementary acts of the vital activity of organisms using the laws of physics, chemistry, etc. In another approach, "life" is seen as quite special and unique phenomenon, which cannot be explained only by the action of the laws of physics and chemistry. That. The main task of biology as a science is to interpret all the phenomena of living nature, based on scientific laws, while not forgetting that the whole organism has properties that are fundamentally different from the properties of the parts that make it up. A neurophysiologist can describe the work of an individual neuron in the language of physics and chemistry, but the phenomenon of consciousness itself cannot be described in this way. Consciousness arises as a result of collective work and simultaneous change in the electrochemical state of millions of nerve cells, but we still do not have a real idea of how thought arises and what are its chemical bases. So, we are forced to admit that we cannot give a strict definition of what life is, and we cannot say how and when it arose. All we can do is list and describe specific features of living matter , which are inherent in all living beings and distinguish them from inanimate matter:
1) The unity of the chemical composition. In living organisms, 98% of the chemical composition falls on 4 elements: carbon, oxygen, nitrogen and hydrogen.
2) Irritability. All living beings are able to respond to changes in the external and internal environment, which helps them survive. For example, the blood vessels in the skin of mammals expand when the body temperature rises, dissipating excess heat and thereby restoring the optimal body temperature again. And a green plant, which stands on the windowsill and is illuminated only from one side, reaches for the light, because a certain amount of illumination is needed for photosynthesis.
3) Movement (mobility). Animals differ from plants in the ability to move from one place to another, that is, the ability to move. Animals need to move in order to get food. Motility is not necessary for plants: plants are able to create their own nutrients from the simplest compounds available almost everywhere. But even in plants one can observe movements within cells and even movements of entire organs, although at a slower speed than in animals. Some bacteria and unicellular algae can also move.
4) Metabolism and energy. All living organisms are capable of exchanging substances with the environment, absorbing from it substances necessary for the body and releasing waste products. Nutrition, respiration, excretion are varieties of metabolism.
Nutrition. All living beings need food. They use it as a source of energy and substances necessary for growth and other life processes. Plants and animals differ mainly in how they obtain food. Almost all plants are capable of photosynthesis, that is, they create their own nutrients using the energy of light. Photosynthesis is one of the forms of autotrophic nutrition. Animals and fungi eat differently: they use the organic matter of other organisms, breaking down this organic matter with the help of enzymes and assimilating the breakdown products. Such nutrition is called heterotrophic. Many bacteria are heterotrophs, although some are autotrophic.
Breath. All life processes require energy. Therefore, the bulk nutrients, obtained as a result of autotrophic or heterotrophic nutrition, is used as an energy source. Energy is released during the process of breathing when some high-energy compounds are broken down. The released energy is stored in molecules of adenosine triphosphate (ATP), which is found in all living cells.
Selection. Excretion, or excretion, is the removal of end products of metabolism from the body. Such poisonous "slags" arise, for example, in the process of breathing, and they must be removed. Animals consume a lot of proteins, and since proteins are not stored, they must be broken down and then removed from the body. Therefore, in animals, excretion is reduced mainly to the excretion of nitrogenous substances. Another form of excretion can be considered the removal from the body of lead, radioactive dust, alcohol and a host of other substances harmful to health.
5) Height. Inanimate objects (such as a crystal or stalagmite) grow by attaching new matter to the outer surface. Living beings grow from the inside due to the nutrients that the body receives in the process of autotrophic or heterotrophic nutrition. As a result of the assimilation of these substances, a new living protoplasm is formed. The growth of living beings is accompanied by development - an irreversible quantitative and qualitative change.
6) Reproduction. The lifespan of each organism is limited, but all living things are "immortal", because. living organisms leave their own kind after death. The survival of the species is ensured by the preservation of the main characteristics of the parents in the offspring that arose through asexual or sexual reproduction. Encoded hereditary information that is passed from one generation to another is contained in the molecules nucleic acids: DNA (deoxyribonucleic acid) and RNA (ribonucleic acid).
7) Heredity- the ability of organisms to transfer their characteristics and functions to the next generations.
8) Variability- the ability of organisms to acquire new signs and properties.
9) Self-regulation . It is expressed in the ability of organisms to maintain the constancy of their chemical composition and functions in the system (for example, the constancy of body temperature), physiological processes in continuously changing environmental conditions. Unlike living matter, dead organic matter is easily destroyed by mechanical and chemical environmental factors. Living beings have a built-in self-regulation system that supports life processes and prevents the uncontrolled decay of structures and substances and the aimless release of energy.
These main signs of the living are more or less pronounced in any organism and serve as the only indicator of whether it is alive or dead. It should not be forgotten, however, that all these signs are only observable manifestations. main property of living matter (protoplasm) - its ability to extract, convert and use energy from outside. In addition, protoplasm is able not only to maintain, but also to increase its energy reserves.
If we look around us, we will see that the world around us is a collection of a wide variety of phenomena, things and objects. All of them are characterized by different properties. Some of them are quite simple, while others are quite complex. Some are microscopic, while others are huge. In order to understand the essence of these things, objects or phenomena, sometimes our senses are enough. And only abstract thinking can help us to comprehend the essence of others.
However, despite all their diversity, all objects, things and phenomena of the surrounding world have one thing in common, the most important feature - they all do not depend on people's consciousness. This is the main property of matter. Thus, we can say that matter is an objective reality.
Basic properties of matter
Currently, the following levels of organization of matter are distinguished:
- Fields and elementary particles;
- Atoms and molecules;
- Gases, liquids and all macro-objects;
- Various space objects (nebulae, galaxies, etc.);
- Objects of wildlife (biological level);
- Society or social level.
The properties of matter, regardless of which level it belongs to, have much in common. These properties include: time, space and movement. It is these properties that ensure the existence of matter.
Matter is infinite and eternal, because in time it has always been, is and will be. Thus, one more general property of matter can be formulated: any kind of matter is uncreated and indestructible. Matter is not taken from nowhere and does not disappear into nowhere, it simply passes from one state to another. This property of matter has found its full confirmation in such well-known laws to all of us as the law of conservation of mass or energy. In accordance with them, one kind of matter may disappear, but right there, its other types will appear, and in an exact quantitative ratio.
Another common property of any matter is reflection. The meaning of this concept lies in the fact that different types of matter interact with each other, which leads to the occurrence of their changes. The simplest example of this is the appearance of footprints in the snow or frost on the window pane.
Properties of living matter
One of the most complex levels of matter organization is the biological level. The distinguishing properties of living matter from non-living matter are:
- Possibility of self-reproduction. Any kind of biological matter can be produced more than once, thanks to the presence of information encoded in DNA molecules;
- Self-regulation of life processes. The process of synthesis and breakdown of substances inside cells is regulated by enzymes that the cell independently produces;
- Growth. It is carried out by increasing the number and size of cells;
- Hierarchy of the organization. The unit of a biological being is the cell. In turn, cells form tissues, tissues form organs, and organs form organ systems;
- Metabolism and energy;
- Nutrition. Obtaining from the external environment substances and energy that are necessary to maintain life;
- Breath;
- Irritability. All living beings are able to respond to changing conditions of the internal and external environment, which ensures the stability of their life. In fact, irritability is a manifestation of another general property of matter - reflection;
- Homeostasis. All living organisms live in an environment that is constantly changing. However, inside the cells, with the help of special autoregulatory mechanisms, the intensity of the course of physiological processes and the constancy of the chemical composition are maintained;
- Motion. All living beings have the ability to move. Although it can have different mechanisms and proceed at different speeds.
Properties of highly organized matter
The human brain is a highly organized matter. One of its main properties is the ability to reflect the world around us, i.e. consciousness. It is thanks to this property that thoughts and emotions arise in a person, the ability to think, cognize surrounding reality, to transformative-practical activity.
Another property of highly organized matter is memory. At its core, it is another manifestation of consciousness.
The human psyche can be called a special property of organized matter. Thanks to this property, people are endowed with the ability not only to receive information about the surrounding reality, but also, on the basis of this, to regulate their internal environment, behavioral patterns. All this allows a person to adapt to living in constantly changing conditions. To put it simply, the properties of highly organized matter allow us to respond correctly to all changes in the environment, to develop new additional forms of interaction with what surrounds us. At the same time, these forms of interaction are much more profitable, flexible and extensive for development and existence than in living organisms, which are limited with the external environment only by physiological relationships.
Properties of living organisms
1. Metabolism and energy with the environment.
2. Irritability(ability to respond to influences).
3. reproduction(self-reproduction).
Levels of organization of living matter
1. Molecular- this is the level of complex organic substances - 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 a 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(a set of populations of different species related to 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 one, the 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
Arrange in the correct order the subordination of systems of different levels, starting with the largest. Write down the corresponding sequence of numbers.
1) connective tissue
2) iron ion
3) erythrocyte
4) hemoglobin
5) shaped elements
6) blood
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 other objects
2) the ability to change its properties under the influence of the environment
3) the ability to respond to environmental influences
4) the ability to participate in the cycle of substances
5) the ability to reproduce their own kind
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
5. Choose two correct answers from five and write down the numbers under which they are indicated. Organisms, unlike inanimate objects, are characterized by
1) change
2) movement
3) homeostasis
4) evolution
5) chemical composition
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. To the cellular level organization of life corresponds
1) chlamydomonas
2) sulfur bacterium
3) bacteriophage
4) kelp
5) lichen
Answer
Choose two options. Energy metabolism in an ordinary 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
Living systems have a number of common properties and features that distinguish them from inanimate nature:
1)high orderliness, which can be maintained only thanks to the processes taking place in them. The composition of all biosystems lying above molecular level, includes certain elements (98% of the chemical composition falls on 4 elements: carbon, oxygen, hydrogen, nitrogen, and in the total mass of substances the main share is water - at least 70 - 85%).
2)Cell structure: All living organisms have a cellular structure, with the exception of viruses.
3)Metabolism. All living organisms are able to exchange substances with the environment, absorbing from it substances necessary for nutrition and respiration, and releasing waste products.
4)Reproduction, or self-reproduction- the ability of living systems to reproduce their own kind.
5)Heredity, which lies in the ability of organisms to transfer their signs, properties and features of development from generation to generation
6)Variability- this is the ability of organisms to acquire new signs and properties; it is based on changes in biological matrices - DNA molecules.
7)Growth and development. Growth is a process that results in a change in the size of an organism (due to cell growth and division). Development is a process that results in a qualitative change in the organism. Under the development of wildlife - evolution is understood as an irreversible, directed, regular change in objects of wildlife, ĸᴏᴛᴏᴩᴏᴇ is accompanied by the acquisition of adaptation (adaptations), the emergence of new species and the extinction of pre-existing forms. The development of the living form of the existence of matter is represented by individual development, or ontogenesis, and historical development, or phylogenesis.
8)Fitness. This is the correspondence between the characteristics of biosystems and the properties of the environment with which they interact. Fitness cannot be achieved once and for all, since the environment is constantly changing (including due to the impact of biosystems and their evolution). For this reason, all living systems are able to respond to environmental changes and develop adaptations to many of them.
9)Irritability. The ability of living organisms to selectively respond to external or internal influences. The reaction of multicellular animals to irritation is carried out through the nervous system and is commonly called a reflex. Organisms that do not have a nervous system are also deprived of reflexes. In such organisms, the reaction to irritation is carried out in different forms: a) taxis - these are directed movements of the body towards the stimulus (positive taxis) b) tropisms - the directed growth of parts of the plant body in relation to the stimulus c) nastia - the movements of parts of the plant in relation to the stimulus (the movement of leaves during daylight hours, depending on the position of the Sun in the sky, or, for example, the opening and closing of the corolla of a flower).
10) Discreteness (division into parts). A separate organism or other biological system (species, biocenosis, etc.) consists of separate isolated, i.e., isolated or delimited in space, but, nevertheless, connected and interacting with each other, forming a structural and functional unity. Cells consist of individual organelles, tissues - from cells, organs - from tissues, etc. This property allows the replacement of a part without stopping the functioning of the whole system and the possibility of specializing different parts for different functions.
11)Autoregulation- the ability of living organisms living in continuously changing environmental conditions to maintain the constancy of their chemical composition and the intensity of the flow of physiological processes - homeostasis. Self-regulation is provided by the activity of regulatory systems - nervous, endocrine, immune, etc.
12)Rhythm. In biology, rhythm is understood as periodic changes in the intensity of physiological functions and shaping processes with different periods of fluctuations (from a few seconds to a year and a century). Rhythm is aimed at coordinating the functions of the organism with the environment, that is, at adapting to periodically changing conditions of existence. thirteen) Energy dependence. Living bodies are systems that are "open" for energy to enter. Under the "open" systems understand dynamic, ie not in a state of rest systems, stable only under the condition of continuous access to them by energy and matter from the outside.
14)Integrity- living matter is organized in a certain way, subject to a number of specific laws characteristic of it.
