With the help of this video lesson, you can independently study the topic “General properties of living organisms.” The living world of our planet represents a huge variety of species, which we will talk about in this lesson. We will look at the general properties of living organisms that help distinguish representatives of living nature from nonliving ones.
BIOLOGY 9TH GRADE
Topic: Introduction
Lesson 2. General properties of living organisms
Anisimov Alexey
biology and chemistry teacher
The living world of the Earth is a huge variety of species: plants, fungi, animals and bacteria. Today, about 2 million species of animals alone are described in science, of which more than 1.5 million are insects, approximately 500 thousand species of plants, over 100 thousand species of fungi and 40 thousand species of protozoa. Bacteria cannot be counted at all. And yet, these organisms have common properties that help us distinguish representatives of living nature from nonliving ones. We'll talk about them today.
When we talk about the differences between living and nonliving nature, it is useful to imagine a stone and a cat or dog. There are differences, and they are obvious. How does science define them? She includes the following processes inherent in almost all living organisms as the characteristics of a living being: nutrition, respiration, excretion, reproduction, mobility, irritability, adaptability, growth and development. Of course, a stone can be mobile if thrown, and can multiply if broken. It may even grow if it is crystalline in nature and is in a saturated saline solution. This requires external influence, but still. At the same time, the stone is unlikely to begin to feed, get irritated and sigh at such injustice. We are talking about the characteristics of living and nonliving things. In them, in these features, the properties of living things are reflected, which cannot be confused with anything else. What are these properties?
First: organisms and their cells contain the same chemical elements as inanimate bodies. But in the cells of living beings there are also organic substances that got their name because they were first isolated from living beings, from organisms. These are proteins, fats, carbohydrates and nucleic acids. These substances form ordered structures. But only when in a cell do organic substances provide manifestations of life. Moreover, the most important role in the life of organisms is given primarily to nucleic acids and proteins. They ensure self-regulation of all processes in the body, its self-reproduction, and therefore life itself. Let us remember: proteins, fats, carbohydrates and nucleic acids are the main components of living things.
Further, the basic structural and functional unit of almost all living organisms is the cell. Almost, because viruses, for example, which are a non-cellular form of life, thrive on Earth, but we will talk about them later. In organisms that have many cells, multicellular organisms, tissues are formed from cells. Tissues form organs, which in turn are combined into organ systems. This orderliness of the structure and functions of organisms ensures the stability and normal course of life.
The third, very important property of living things: metabolism. Metabolism is the totality of all chemical reactions, all transformations of substances entering the body from the external environment during the process of nutrition and respiration. Thanks to metabolism, the orderliness of vital processes and the integrity of the body itself are maintained, and the constancy of the internal environment in the cell and in the body as a whole is maintained. In other words, the metabolism and energy ensures the constant connection of the organism with the environment and the maintenance of its life.
Fourth: this is reproduction. The living always comes from the living. Therefore, the question “What came first: the chicken or the egg?” not important for general biology. Ultimately, the chicken still reproduces the chicken, and the man reproduces the man. Therefore, life can be considered as the reproduction of similar creatures or self-reproduction. And this is a very important property of living things, which ensures the continuity of the existence of life.
Fifth: if you kick a stone, it will not respond or react in any way. This trick will not work with a dog: the predator will respond to aggression with aggression. Because living beings actively react to the actions of environmental factors, thus showing irritability. It is irritability that allows organisms to navigate the environment and, therefore, survive in changing conditions. Even plants that seem to lack mobility can respond to changes. Many are able to turn their leaves towards the sun to get more light, and some, such as Mimosa Shy, curl their leaves when touched. These are also manifestations of irritability.
The sixth property is adaptability. If you pay attention to the appearance of the giraffe, you can see that it is ideally adapted to exist in the conditions of the African savannah. A long neck helps him get food where no one can get it, long legs help him run quickly and fight off predators. But a giraffe will not survive in the Arctic, but polar bears feel great there. Organisms can adapt over millions of years, and this is called evolution. Evolution is another important property of living things. Living organisms change over time, most often irreversibly. These changes are called development.
Development is usually accompanied by growth, an increase in body weight or size associated with the appearance of new cells. Evolution is also development, but not of one individual organism, but of the entire living world as a whole. Development usually proceeds from simple to complex and to greater adaptability of the organism to its environment. This ensures the diversity of living beings that we can observe today.
We identified the differences between living and nonliving things and became familiar with the common properties of all living organisms. Next time we will talk about the diversity of living beings on our planet and the levels of organization of living things. See you.
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Slide captions:
General properties of living organisms
Unique life forms
General properties of living things 1. Chemical composition (C, O, N, H – 98%)! Carbohydrates, proteins, fats and nucleic acids are the main components of living things.
2. Cellular structure The cell is the basic structural and functional unit of almost all living organisms.
Structural units of a plant Cell Tissue Organs Organism
The orderliness of the structure and functions of organisms ensures stability and normal life.
3. Metabolism is a set of numerous chemical transformations of substances occurring in the body that come from the external environment during nutrition and respiration.
Metabolism and energy ensure the body’s constant connection with the environment and maintain its life
4. Self-reproduction All living things come from living things
Self-reproduction is the most important property of living things, supporting the continuity of the existence of life
5. Irritability is a property of living things that allows organisms to navigate the environment and, therefore, survive in changing conditions
Irritability
6. Adaptation is manifested in features: external and internal structure, functions, behavior of organisms, rhythms of their active life, geographical distribution
7. Development and growth Development - irreversible qualitative changes in the properties of living organisms Growth - an increase in the size and weight of the organism associated with the appearance of new cells
The ability to grow and develop is a general property of living things.
8. Evolution Evolution (Latin evolutio - deployment) is a long historical process of the development of nature! Evolution is a general property of the living world
Evolution
Homework § 2, ? (1-3) Workbook
On the topic: methodological developments, presentations and notes
The test is intended for 6th grade students studying biology using N.I. Sonin’s textbook “Living Organism”. It is carried out after studying the topic “Organs of flowering plants”. The work uses...
Explanatory note
The outline of this educational lesson was developed for 9 classes of the basic level of studying biology. The lesson was developed according to the program of secondary (complete) general education in biology, author V.B. Zakharov, (Programs for general education institutions, new educational standard, Biology grades 5 - 11. - M.: Bustard, 2011). The topic of this training session is included in section No. 1 of the thematic plan “Basic properties of living organisms.”
Draft lesson notes
Magnitogorsk city
Municipal educational institution secondary school No. 5 UIM
Teacher: Subbotina Larisa Petrovna
Class 9
Item biology
Subject educational lesson: “Basic properties of living organisms”
Duration training session: 45 minutes
Type of training session: combined lesson.
Teaching methods: problematic - dialogue.
Goals: Systematization of students’ knowledge about the properties of living systems.
Tasks:
Give the concept of life and living systems;
Develop ideas about the characteristics of living systems;
Learn to find and analyze the necessary information;
Foster a culture of educational work.
Interdisciplinary connections:
. Inorganic chemistry (table of elements of D.I. Mendeleev’s periodic system);
. Organic chemistry (carbohydrates, fats, proteins);
Meta-subject results are:
1) the ability to organize one’s educational activities: determine the purpose of the work, set tasks, plan - determine the sequence of actions and predict the results of the work.
2) the ability to find information about biological objects in different sources and work with the textbook text, highlighting the main thing; to make plan; analyze information, define concepts;
3) the ability to listen and engage in dialogue, participate in collective discussion of problems; give a reasoned assessment of new information on biological issues.
The subject results are:
Identification of essential features of biological objects (cells and organisms of plants, animals, fungi and bacteria; the human body;) and processes (metabolism and energy conversion, nutrition, respiration, excretion, transport of substances, growth, development, reproduction, regulation of the body’s vital functions);
Comparison of biological objects and systems of inanimate nature, the ability to draw conclusions and conclusions based on comparison;
Mastering the methods of biological science: describing biological objects and processes and explaining their results, the ability to draw conclusions and conclusions.
Personal results are:
1) Cognitive interest in natural sciences. Understanding the unity of living nature based on the common properties of living organisms.
Equipment: classroom with 1 computer and multimedia installation, living plants: decorative flowering plants, indoor plants (begonia, balsam, fuchsia, zonal pelargonium), table: “Human systems”, animal models, 1C program system: Education 3.0, Biology 6 - 11 class, table of elements of the periodic system D.I. Mendeleev, TsOR: “Basic properties of living organisms.”
Progress of the training session.
1. Stage of the training session: Organizing time.
Time: 1 minute
Goal: To tune in to the perception of new material
Competencies: Know the rules of behavior in the classroom. Know how to prepare for a lesson.
Methods: verbal
Shape: frontal
| Teacher activities | Student activity |
| Greets students. Checks readiness for the lesson. | Getting ready for the lesson. Greetings from the teachers. |
| Form of control: pedagogical observation |
|
2. Training session stage: Updating knowledge on the topic. Determining the topic of the lesson.
Time: 10 minutes
Goal: Expand the concept of life.
Competencies: ability to listen, perceive goals, draw conclusions.
Method: Explanatory and illustrative
| Teacher activities | Student activity |
| Informs the topic of the lesson (Appendix No. 1), lesson plan. Today we will fully reveal the concept of life, as well as the properties of living systems on planet Earth. (Appendix No. 2) He suggests opening the textbook on page 11 and independently reading the definition of life according to F. Engels and M.V. Wolkenstein. (Appendix No. 3) | Write down the topic of the lesson in your notebook. Actively listen. They give examples of life from different perspectives, using knowledge of chemistry, physics and anatomy. Write it down in your workbook. |
3. Stage of the training session: Learning new material
Time: 30 minutes
Goal: Systematization of students’ knowledge about the properties of living systems.
Competencies: Know basic biological concepts, choose the main thing, perceive goals, draw conclusions.
Method: Explanatory and illustrative, independent work with a textbook.
Digital resources used: 1C program system: Education 3.0, Biology grades 6 -9. Plants. Mushrooms. Lichens. Zoology 7th grade. Anatomy 8th grade.
| Teacher activities | Student activity |
||||||||||||||||
| Invites students to recall from previously studied courses what they know about the characteristics of living and nonliving systems, then demonstrates a fragment of the COR. Indicates the general similarity of all living organisms - chemical composition. Sets tasks: What chemical elements do substances consist of? Are there chemical elements that are unique to living organisms? At the same time, on the screen is a table of elements of the periodic table by D.I. Mendeleev .(Appendix No. 4) Explains the properties of molecules of organic substances, and then carries out independent work. Suggests opening the textbook on pp. 9 - 10, reading independently and writing down the properties of living organisms in a workbook: 1.What is metabolism? The teacher leads students to generalize the processes, arguing that assimilation and dissimilation are opposite processes; in the first case, substances are formed, in the second, they are destroyed. (Appendix No. 5) Offers to fill out the diagram. 2. What is self-reproduction (reproduction)? What is it based on? (Appendix No. 6) Offers to check the assumptions by looking at the materials of the Center. 3.What is growth and development? Shows photographs of people, from babies to the elderly. Gives the task to formulate a definition of the concepts of “individual development” and “historical development” (Appendix No. 7) 4.What is heredity? (Appendix No. 8) 5 .What is variability? Why are descendants not identical to their parents? (Appendix No. 9) He suggests drawing up a drawing in notebooks on the topic: “The Fate of the Three Peas” (different fates depending on environmental conditions). 6.What is irritability? What is its significance for adaptation to environmental conditions? (Appendix No. 10) He suggests drawing up a drawing in their notebooks on the topic: “Nutrition of an amoeba” and “Amoebae in a salty drop,” where students must draw vectors for the movement of the amoeba. | Actively listen. They take part in the dialogue. Complete tasks. Fill out the table. Comparative characteristics of the content of chemical elements in living and inanimate nature.
Form of control: self-control by working in pairs. Discussing mistakes. They lead to the conclusion about the stability of large molecules and the complexity of the organization of living matter. Carry out the teacher's assignment. Students recall previously studied material and, with the help of teacher correction, generalize the concept of metabolism. Give examples of metabolism in plant and animal organisms, using knowledge of botany, zoology and anatomy. Independent work. Discuss and write down the conclusions in a notebook: dissimilation and assimilation are closely interrelated and are impossible without each other. After all, if complex substances are not synthesized in the cell, then there will be nothing to disintegrate when energy is needed Students recall previously studied material and, with the help of teacher correction, generalize the concept self-reproduction as the main feature of species prolongation. One student makes a generalization and says that multicellular organisms, under different environmental conditions, can reproduce both asexually and sexually. Discuss and write down the conclusions in a notebook: in animals, evolution proceeds from hermaphrodites to dioecious, from external to internal fertilization, from eggs, then larval membranes, to intrauterine gestation of the organism (with care for the offspring). They offer versions of the answer. Independent work with the textbook. Write down the definitions of “ontogenesis” and “phylogeny” in a notebook. Students recall previously studied anatomy material. Independent work. They present their arguments: This is the ability of organisms to transmit their characteristics and properties from generation to generation. Promotes the emergence of new characteristics, and therefore better adaptability of organisms to their habitat. Independent work in pairs. They come up with, draw, draw conclusions: This is the ability of organisms to acquire their own characteristics in the process of ontogenesis. Individuals most adapted to specific environmental conditions are selected and survive. Leads to the emergence of new forms of life, the emergence of new species. Students recall previously studied material in zoology and, with the help of teacher correction, generalize the concept of irritability. Independent work. Discuss the results of the work. |
3. Training session stage Consolidation of knowledge.
Time: 3 minutes
Purpose: to check the degree of knowledge acquisition on the topic: “Basic properties of living organisms”
Competencies: Know basic biological concepts, choose the main thing, draw conclusions.
Method: verbal.
Digital resources used: no
| Teacher activities | Student activity |
| Summarizes the work. Organizes a discussion of work results in class. | Draw conclusions based on the topic of the lesson: Living organisms differ from nonliving systems - objects studied by chemistry and physics - by their exceptional complexity and high structural and functional order. |
4. Study phase Final part. Discussion of homework.
Time: 1 minute
APPENDIX No. 1
Biology – life science, studies all manifestations of life: the structure, functions, development and origin of living organisms, their relationships in natural communities with the environment and with other living organisms.
A special form of movement of matter;
Metabolism and energy in the body;
Vital activity in the body;
Self-reproduction of organisms, which is ensured by the transfer of genetic information from generation to generation.
APPENDIX No. 2
APPENDIX No. 3
Definition of life.
Modern dialectical - materialistic:
Life - This is a qualitatively special and higher form of existence, development and movement of matter.
Life - a method of existence of protein bodies, the essential point of which is the constant self-renewal of the chemical components of these bodies.(F. Engels “Anti-Dühring”)
Living bodies existing on Earth are open, self-regulating and self-reproducing systems built from biopolymers - proteins and nucleic acids. (M. V. Volkenshtein)
Life - it is a macromolecular system with a certain hierarchical organization, capable of reproduction, metabolism and regulated energy flow.(K. Grobstein)
APPENDIX No. 4
APPENDIX No. 5
Plastic exchange Energy metabolism
Assimilation Dissimilation
Anabolism Catabolism
simple substances complex substances
Question 1. Name the levels of organization of living matter. Suggest criteria for comparing different levels of living organization; draw up and fill out the table “Levels of Living Matter”.
Currently, there are several levels of organization of living matter.
1. Molecular.
2. Cellular.
3. Fabric.
4. Organ.
5. Organic.
7. Biogeocenotic (ecosystem).
8. Biosphere.
Each of these levels is quite specific, has its own patterns, its own research methods. It is even possible to single out sciences that conduct their research at a certain level of organization of living things. For example, at the molecular level living things are studied by such sciences as molecular biology, bioorganic chemistry, biological thermodynamics, molecular genetics, etc. Although the levels of organization of living things are distinguished, they are closely interconnected and flow from one another, which speaks of the integrity of living nature.
Question 2. How are the different levels of organization of living matter interconnected?
When answering the question about the mutual connection between different levels of organization of living matter, one should keep in mind that each level of organization is determined by a group of system-forming factors, i.e. factors that are leading in the formation of a given system (for example, water is a system-forming factor in the formation of aquatic ecosystems) . But, in fact, there is always a group of interconnected system-forming factors (in relation to water, these are temperature, salinity, osmotic pressure of water). The unifying factor within each level of organization is the metabolism and energy characteristic of that level. However, despite the specificity of each level of organization, they are all interconnected and subject to the general laws of the existence of living matter. Each subsequent level of organization is a consequence of the previous one (for example, the cellular level of organization follows from the molecular level). The factor that unites all levels of organization into a single whole - the biosphere - is biotic metabolism.
Question 3. What is self-reproduction (reproduction) of living organisms?
Self-reproduction or the ability to reproduce, that is, to reproduce a new generation of individuals of the same species, is one of the main properties of living organisms. The offspring are basically always similar to their parents, therefore the ability of organisms to reproduce their own kind is closely related to the phenomenon of heredity.
Question 4. What is development? What forms of development do you know? Compare them with each other.
Development is understood as an irreversible, directed, natural change in objects of living and inanimate nature. The development of living matter is represented by the individual development of organisms, or ontogenesis, and historical development, or phylogeny.
Phylogenesis, or evolution, is the irreversible and directed development of living nature, accompanied by the formation of new species and the progressive complication of life forms. The result of evolution is the entire diversity of living organisms on Earth.
Question 5. What is irritability? What significance does it have for adaptation to living conditions?
An inherent property of living beings is irritability (the ability to perceive external or internal stimuli (impacts) and respond adequately to them). It manifests itself in changes in metabolism (for example, when daylight hours shorten and the ambient temperature drops in autumn in plants and animals), in the form of motor reactions, and highly organized animals (including humans) are characterized by changes in behavior. A characteristic reaction to irritation in almost all living beings is movement, that is, spatial movement of the entire organism or individual parts of their body. This is characteristic of both unicellular (bacteria, amoebas, ciliates, algae) and multicellular (almost all animals) organisms. Some multicellular cells also have mobility (for example, phagocytes in the blood of animals and humans). Multicellular plants, compared to animals, are characterized by low mobility, however, they also have special forms of manifestation of motor reactions. Their active movements are of two types: growth and contractile. The first, slower ones include, for example, the extension of the stems of houseplants growing in the window towards the light (due to their one-sided lighting). Contractile movements are observed in insectivorous plants (for example, the rapid folding of leaves of a sundew when catching insects landing on it).
Question 6. Based on the knowledge acquired in the “Man” course, give examples of self-regulation of physiological processes in your body.
An example of self-regulation is maintaining a constant human body temperature
For example, a person is in a hot climate, the body temperature becomes higher than normal, then the capillaries expand, the blood comes close to the surface of the skin, where it cools, therefore the body temperature decreases. Another example: a person is in conditions with a low ambient temperature, then the capillaries located in the skin narrow, and then the blood cools less, therefore the body temperature remains constant.
Question 7. What is the importance of the rhythm of life processes? Give examples of the rhythm of processes in inanimate and living nature.
The rhythm of biological processes is an integral property of living matter. Living organisms live for many millions of years under conditions of rhythmic changes in the geophysical parameters of the environment (change of seasons, change of day and night, etc.). Biorhythms are an evolutionarily fixed form of adaptation that determines the survival of organisms by adapting them to rhythmically changing environmental conditions. The fixation of these biorhythms ensured the anticipatory nature of changes in functions, i.e. functions begin to change even before corresponding changes occur in the environment. The advanced nature of changes in functions has a deep adaptive meaning and significance, preventing the tension of restructuring the body's functions under the influence of factors already acting on it.
Biological rhythms are described at all levels, from the simplest biological reactions in a cell to complex behavioral reactions. Thus, a living organism is a collection of numerous rhythms with different characteristics.
The concept of “rhythm” is associated with the idea of harmony, organization of phenomena and processes. Translated from Greek, the word “rhythm”, “rhythmos” means proportionality, harmony. Rhythmic are those natural phenomena that are repeated periodically. This is the movement of celestial bodies, the change of seasons, day and night, the periodicity of ebb and flow. As well as the alternation of maxima and minima of solar activity.
Various physical phenomena have a periodic, wave-like character. These include electromagnetic waves, sound, etc. An example in life is the change in the atomic weight of elements, reflecting the sequential alternation of the chemical properties of matter. The basic rhythms in nature, which left their mark on all life on Earth, arose under the influence of the rotation of the Earth in relation to the Sun, Moon and stars. A natural system is an open system, that is, it is subject to the influence of other natural systems. This means that rhythms within one system can be determined by the rhythms of other systems through interactions between systems.
Question 8. Try to formulate your own definition of life.
Life is a way of being for entities (living organisms) endowed with internal activity, the process of development of bodies of organic structure with a stable predominance of synthesis processes over decay processes, a special state of matter achieved through the following properties.
Life is a way of existence of protein bodies and nucleic acids, the essential point of which is the constant exchange of substances with the environment, and with the cessation of this exchange, life also ceases.
Biological
Life is a special type of material interaction of genetic objects that carry out the synthesis (production) of similar genetic objects.
Chemical-physical
Life is the predominance of synthesis processes over decay processes, a pool of energy-consuming processes of change in matter and other objects of physical chemistry, in which two cycles are distinguishable (in time):
Chemical wave model
Life is a chemical wave, that is, a multidimensional catalytic cyclic chemical reaction. At each moment of its existence, called the lifetime, in each individual thread of the reaction at any level of scale of consideration from molecules to classes of living organisms, three material elements can be distinguished: resource, catalyst, result.
Cybernetic
Life is a cybernetic structure that implements specific information functions:
memory, systems for encoding, recording, transmitting, receiving, decoding and interpreting (executing) control information,
its own internal language - a system of signals, properties and methods.
The ability to “listen” and “speak” in the internal language (process signals, performing information functions)
Thermodynamic
Life is a process of one-way exchange of information about structure between a limited part of a material system and its environment, using the effect of one-way conductivity of membranes. The conductivity of the membrane of a living organism in the direction “inside the body” is high for information, but low for entropy. In the “out of the body” direction it is the other way around: the conductivity for information is low, and for entropy it is high. An example of such a membrane is the physical boundary of any two different media.
Technological
Biological life - protein bodies capable of independently controlling the synthesis or modification of protein.
Religious
Life is a wonderful property that does not depend on matter, given and taken from matter by God. There is a distinction between the finite (in time) life of the body and the infinite life of the soul. A living organism is one in whose body a soul exists.
Philosophical
Life is an ideal form of existence of matter, capable of randomly (at will) influencing matter and adjusting cause-and-effect relationships for itself (adapt). The terrestrial form of life known to us arose as a result of the evolution of polymeric carbon compounds and is represented by a variety of organisms, each of which is an individual integral system possessing:
complex structure and metabolism.
Question 9. Give examples of processes and events occurring at different levels of the organization of living things, of which you were a participant today.
At the molecular level, metabolic and energy processes are constantly taking place as we eat food every day. At the organismal level, processes of adaptation to the environment take place. We choose a safe route from school to home, dress according to weather conditions.
With the help of this video lesson, you can independently study the topic “General properties of living organisms.” The living world of our planet represents a huge variety of species, which we will talk about in this lesson. We will look at the general properties of living organisms that help distinguish representatives of living nature from nonliving ones.
BIOLOGY 9TH GRADE
Topic: Introduction
Lesson 2. General properties of living organisms
Anisimov Alexey
biology and chemistry teacher
The living world of the Earth is a huge variety of species: plants, fungi, animals and bacteria. Today, about 2 million species of animals alone are described in science, of which more than 1.5 million are insects, approximately 500 thousand species of plants, over 100 thousand species of fungi and 40 thousand species of protozoa. Bacteria cannot be counted at all. And yet, these organisms have common properties that help us distinguish representatives of living nature from nonliving ones. We'll talk about them today.
When we talk about the differences between living and nonliving nature, it is useful to imagine a stone and a cat or dog. There are differences, and they are obvious. How does science define them? She includes the following processes inherent in almost all living organisms as the characteristics of a living being: nutrition, respiration, excretion, reproduction, mobility, irritability, adaptability, growth and development. Of course, a stone can be mobile if thrown, and can multiply if broken. It may even grow if it is crystalline in nature and is in a saturated saline solution. This requires external influence, but still. At the same time, the stone is unlikely to begin to feed, get irritated and sigh at such injustice. We are talking about the characteristics of living and nonliving things. In them, in these features, the properties of living things are reflected, which cannot be confused with anything else. What are these properties?
First: organisms and their cells contain the same chemical elements as inanimate bodies. But in the cells of living beings there are also organic substances that got their name because they were first isolated from living beings, from organisms. These are proteins, fats, carbohydrates and nucleic acids. These substances form ordered structures. But only when in a cell do organic substances provide manifestations of life. Moreover, the most important role in the life of organisms is given primarily to nucleic acids and proteins. They ensure self-regulation of all processes in the body, its self-reproduction, and therefore life itself. Let us remember: proteins, fats, carbohydrates and nucleic acids are the main components of living things.
Further, the basic structural and functional unit of almost all living organisms is the cell. Almost, because viruses, for example, which are a non-cellular form of life, thrive on Earth, but we will talk about them later. In organisms that have many cells, multicellular organisms, tissues are formed from cells. Tissues form organs, which in turn are combined into organ systems. This orderliness of the structure and functions of organisms ensures the stability and normal course of life.
The third, very important property of living things: metabolism. Metabolism is the totality of all chemical reactions, all transformations of substances entering the body from the external environment during the process of nutrition and respiration. Thanks to metabolism, the orderliness of vital processes and the integrity of the body itself are maintained, and the constancy of the internal environment in the cell and in the body as a whole is maintained. In other words, the metabolism and energy ensures the constant connection of the organism with the environment and the maintenance of its life.
Fourth: this is reproduction. The living always comes from the living. Therefore, the question “What came first: the chicken or the egg?” not important for general biology. Ultimately, the chicken still reproduces the chicken, and the man reproduces the man. Therefore, life can be considered as the reproduction of similar creatures or self-reproduction. And this is a very important property of living things, which ensures the continuity of the existence of life.
Fifth: if you kick a stone, it will not respond or react in any way. This trick will not work with a dog: the predator will respond to aggression with aggression. Because living beings actively react to the actions of environmental factors, thus showing irritability. It is irritability that allows organisms to navigate the environment and, therefore, survive in changing conditions. Even plants that seem to lack mobility can respond to changes. Many are able to turn their leaves towards the sun to get more light, and some, such as Mimosa Shy, curl their leaves when touched. These are also manifestations of irritability.
The sixth property is adaptability. If you pay attention to the appearance of the giraffe, you can see that it is ideally adapted to exist in the conditions of the African savannah. A long neck helps him get food where no one can get it, long legs help him run quickly and fight off predators. But a giraffe will not survive in the Arctic, but polar bears feel great there. Organisms can adapt over millions of years, and this is called evolution. Evolution is another important property of living things. Living organisms change over time, most often irreversibly. These changes are called development.
Development is usually accompanied by growth, an increase in body weight or size associated with the appearance of new cells. Evolution is also development, but not of one individual organism, but of the entire living world as a whole. Development usually proceeds from simple to complex and to greater adaptability of the organism to its environment. This ensures the diversity of living beings that we can observe today.
We identified the differences between living and nonliving things and became familiar with the common properties of all living organisms. Next time we will talk about the diversity of living beings on our planet and the levels of organization of living things. See you.