Liquid bubbles surrounded by protein films. Biology test "origin and initial stages of the origin of life". Comparative characteristics of experiments

Origin of life

1. Coacervates were the first living organisms on Earth.

2. The theory of abiogenesis suggests the possibility of the origin of the living only from the living.

3. Pasteur proved by his experiments the impossibility of spontaneous generation of life.

4. The most significant feature of Oparin's hypothesis is the gradual complication of the chemical structure and morphological exchange of precursors. Life on the way to living organisms.

5. Coacervates are not able to adsorb a substance from the surrounding solution.

6. Life arose in a biogenic way.

7. Life on Earth appeared about 3.5 million years ago

8. At present, spontaneous generation of living organisms is impossible on Earth.

9. Coacervates are fluid bubbles surrounded by protein films.

10. The first living organisms on our planet were aerobic heterotrophs.

Origin of life

1. Coacervates were the first living organisms on Earth.

2. The theory of abiogenesis suggests the possibility of the origin of the living only from the living.

3. Pasteur proved by his experiments the impossibility of spontaneous generation of life.

4. The most significant feature of Oparin's hypothesis is the gradual complication of the chemical structure and morphological exchange of precursors. Life on the way to living organisms.

5. Coaervates are not able to adsorb a substance from the surrounding solution.

6. Life arose in a biogenic way.

7. Life on Earth appeared about 3.5 million years ago

8. At present, spontaneous generation of living organisms is impossible on Earth.

9. Coacervates are fluid bubbles surrounded by protein films.

10. The first living organisms on our planet were aerobic heterotrophs.

Origin of life

1. Coacervates were the first living organisms on Earth.

2. The theory of abiogenesis suggests the possibility of the origin of the living only from the living.

3. Pasteur proved by his experiments the impossibility of spontaneous generation of life.

4. The most significant feature of Oparin's hypothesis is the gradual complication of the chemical structure and morphological exchange of precursors. Life on the way to living organisms.

5. Coacnervates are not able to adsorb a substance from the surrounding solution.

6. Life arose in a biogenic way.

7. Life on Earth appeared about 3.5 million years ago

8. At present, spontaneous generation of living organisms is impossible on Earth.

9. Coacervates are fluid bubbles surrounded by protein films.

10. The first living organisms on our planet were aerobic heterotrophs.

"Development of the Earth" - Exhausted, supporting each other, burning our feet on hot sand, we wandered through low thickets of thorny eucalyptus bushes for five days. HALL No. 2 1. Based on the proposed paintings, determine the name and show these natural areas on the map. 2. Sounds we recognize. What does the title mean? HALL № 1 Practical work: 1. Examine the proposed exhibits. 2. Determine: a) Which specimens are fossil remains of organisms (fossils) b) Which specimens are reconstructable. 3. Formulate a conclusion: Why is it necessary to study the fossil remains of organisms? 4. From the proposed letters, add up the name of the science that studies ancient fossils.

“The emergence and development of life” - Heraclitus. The possibility of re-life on Earth is excluded. Life originated on Earth in an abiogenic way. The world consists of five elements: earth, water, air, fire, and ether. The basis of everything is fire ... Aristotle. The beginnings of the universe are atoms and emptiness. The emergence and initial development of life on Earth.

"Development of the organic world" - Today we are experiencing one of the periods of warming. Spread across the equator is the supercontinent Gondwana. PALEOCENE EPOCH (Tertiary period). Flora As the climate cooled, steppes came to replace the forests. Duration: FROM 570 TO 500 MILLION. Cenozoic era (era of new life). Duration: FROM 65 TO 55 MILLION

"Theory of Life" - Scientific. Consider monotheism. Monotheism is one of the branches of creationism. Consider the example of Christianity. BUT still, in the religion of ancient Egypt there are many gods. Spontaneous origin of life: For Democritus, the beginning of life was in silt, for Thales - in water, for Anaxagoras - in the air. Ancient Egypt.

"The Education of Life" - Paleozoic. Star formation. Archaeus. Proterozoic.

"Development of Life on Earth" - The project is designed for two weeks. Project on the topic Stages of development of life on Earth. The creative name is "An imperturbable system in everything, a complete consonance in nature" F.I. Tyutchev. Developing: to promote the development of information culture and the formation of interest in research work. Subject: biology. © Lyubimskaya secondary school, 2010

In total there are 20 presentations in the topic

1.

a) the composition of inorganic compounds; b) the presence of catalysts;

2.

3. Such a general property of the living as self-regulation includes:

a) heredity; b) variability; c) irritability; d) ontogeny.

4. The essence of the theory of abiogenesis is:

5. The crystal is not a living system, because:

c) he is not characterized by irritability; d) not all the properties of a living thing are inherent in it.

6. The experiments of Louis Pasteur proved the possibility:

7.

a) radioactivity; b) the presence of liquid water; c) the presence of gaseous oxygen; d) the mass of the planet.

8. Carbon is the basis of life on Earth, because He:

a) is the most common element on Earth;
b) the first of the chemical elements began to interact with water; c) has a small atomic weight;

9. Eliminate the superfluous: a) 1668; b) F. Redi; c) meat; d) bacteria.

10.

a) L. Pasteur; b) A. Levenguk; c) L. Spallanzani; d) F. Redi.

Part B Complete the sentences. 1. The theory postulating the creation of the world by God (Creator) - ... .

2. Pre-nuclear organisms that do not have a nucleus limited by a shell and organelles capable of self-reproduction - ....

3. A phase-separated system interacting with the external environment as an open system is ....

4. The Soviet scientist who proposed the coacervate theory of the origin of life, - ....

5. The process by which an organism acquires a new combination of genes is ... .

Part C Give short answers to the following questions.

1. What are the common features of living and non-living matter?

2. Why, when the first living organisms appeared in the Earth's atmosphere, there had to be no oxygen?

3. What was Stanley Miller's experience? What corresponded to the "primary ocean" in this experience?

4. What is the main problem of the transition from chemical to biological evolution?

5. List the main provisions of the theory of A.I. Oparina.

Topic "The origin of life on Earth" Option 2 Part A Write the correct answers.

1. Living differs from non-living:

c) interaction of molecules with each other; d) metabolic processes.

2. The first living organisms on our planet were:

a) anaerobic heterotrophs; b) aerobic heterotrophs; c) autotrophs; d) symbiont organisms.

3.

4. The essence of the theory of biogenesis is:

a) the origin of the living from the non-living; b) the origin of the living from the living;
c) the creation of the world by God; d) bringing life from space.

5. A star is not a living system, because:

c) she does not have irritability; d) not all properties of the living are inherent in it.

6.

a) spontaneous generation of life; b) the appearance of the living only from the living;

c) bringing "seeds of life" from the Cosmos; d) biochemical evolution.

7. Of these conditions, the most important for the emergence of life is:

a) radioactivity; b) the presence of water; c) the presence of an energy source; d) the mass of the planet.

8. Water is the basis of life, because:

a) is a good solvent; b) has a high heat capacity;
c) increases its volume when it freezes; d) has all of the above properties.

9. Eliminate the superfluous: a) 1924; b) L. Pasteur; c) meat broth; d) bacteria.

10. Arrange the following names in logical order:

a) L. Pasteur; b) S. Miller; c) J. Haldane; d) A.I. Oparin.

Part B Complete the sentences. 1. The process of formation by living organisms of organic molecules from inorganic ones due to the energy of sunlight - .... 2. Pre-cellular formations that possessed some properties of cells (the ability to metabolism, self-reproduction, etc.) - ....

3. Separation of a protein solution containing other organic substances into phases with a greater or lesser concentration of molecules - ....

4. An English physicist who suggested that adsorption was one of the stages in the concentration of organic substances in the course of prebiological evolution - ... .

5. The system of recording hereditary information in DNA molecules in the form of a sequence of nucleotides, characteristic of all living organisms, is ....

Part C

1. What was Stanley Miller's experience? What corresponded to "lightning" in this experiment?

2. Why should the mass of a planet on which life can arise be no more than 1/20 of the mass of the Sun?

3. To what stage of the development of life on Earth can the words of the Gogol hero be attributed: “I don’t remember the number. There was no month either. What the hell was that?”

4. What conditions are necessary for the origin of life?

5. What is panspermia? Which scientists you know adhered to this theory?

Topic "The origin of life on Earth" Option 3 Part A Write the correct answers.

1. Living differs from non-living:

a) the composition of inorganic compounds; b) the ability to self-reproduce;
c) interaction of molecules with each other; d) metabolic processes.

2. The first living organisms on our planet were:

a) anaerobic heterotrophs; b) aerobic heterotrophs; c) autotrophs; d) symbiont organisms.

3. Such a general property of the living as self-renewal includes:

a) metabolism; b) reproduction; c) irritability; d) ontogeny.

4. The essence of creationism is:

a) the origin of the living from the non-living; b) the origin of the living from the living;

c) the creation of the world by God; d) bringing life from space.

5. The river is not a living system because:

a) it is not capable of growth; b) it is not capable of reproduction;
c) she is not capable of irritability; d) not all properties of the living are inherent in it.

6. The experience of Francesco Redi proved the impossibility:

a) spontaneous generation of life; b) the appearance of the living only from the living;
c) bringing "seeds of life" from outer space; d) biochemical evolution.

7. Of these conditions, the most important for the emergence of life is:

a) radioactivity; b) the presence of water; c) an infinitely long time of evolution; d) a certain mass of the planet.

8. During the emergence of life in the Earth's atmosphere, there should have been no oxygen, because:

a) it is an active oxidizing agent; b) has a high heat capacity;
c) increases its volume when it freezes; d) all of the above combined.

9. Eliminate the superfluous: a) 1953; b) bacteria; c) S. Miller; d) abiogenic synthesis.

10.

a) L. Pasteur; b) F. Redi; c) L. Spallanzani; d) A.I. Oparin.

Part B Complete the sentences. 1. The formation of organic molecules from inorganic outside living organisms - ....

2. Bubbles of liquid surrounded by protein films, arising from the agitation of aqueous solutions of proteins, - ....

3. The ability to reproduce biological systems similar to itself, which manifests itself at all levels of the organization of living matter, is ... .

4. An American scientist who proposed a thermal theory of the origin of protobiopolymers, - ... .

5. Protein molecules that accelerate the course of biochemical transformations in aqueous solutions at atmospheric pressure -

Part C Give a short answer to the question.

1. What is the main difference between burning wood and "burning" glucose in cells?

2. What are the three modern points of view on the problem of the origin of life?

3. Why is carbon the basis of life?

4. What was Stanley Miller's experience?

5. What are the main stages of chemical evolution?

Topic "The origin of life on Earth" Option 4 Part A Write the correct answers.

1. Living differs from non-living:

a) the composition of inorganic compounds; b) the ability to self-regulate;
c) interaction of molecules with each other; d) metabolic processes.

2. The first living organisms on our planet were:

a) anaerobic heterotrophs; b) aerobic heterotrophs; c) autotrophs; d) symbiont organisms.

3. Such a general property of the living as self-reproduction includes:

a) metabolism; b) reproduction; c) irritability; d) ontogeny.

4. The essence of the theory of panspermia is:

a) the origin of the living from the non-living; b) the origin of the living from the living;
c) the creation of the world by God; d) bringing to Earth the "seeds of life" from the Cosmos.

5. The glacier is not a living system because:

a) he is incapable of growth; b) he is not capable of reproduction;
c) he is not capable of irritability; d) not all the properties of a living thing are inherent in it.

6. The experience of L. Spallanzani proved the impossibility:

a) spontaneous generation of life; b) the appearance of the living only from the living;
c) bringing "seeds of life" from the Cosmos; d) biochemical evolution.

7. Of these conditions, the most important for the emergence of life is:

a) radioactivity; b) the presence of water; c) the presence of certain substances; d) a certain mass of the planet.

8. Carbon is the basis of life, because He:

a) is the most common element on Earth; c) has a small atomic weight;
b) the first of the chemical elements began to interact with water;
d) is able to form stable compounds with double and triple bonds.

9. Eliminate the excess: a) DNA; b) genetic code; c) chromosome; d) cell membrane.

10. Arrange the following names in logical order:

a) A.I. Oparin; b) L. Pasteur; c) S. Miller; d) J. Haldane.

Part B Complete the sentences. 1. Organisms with a limited shell of the nucleus, having self-reproducing organelles, internal membranes and cytoskeleton, - ....

2. The system of recording hereditary information in DNA molecules in the form of a sequence of nucleotides, characteristic of all organisms, is ....

3. The ability to reproduce biologically similar systems, which manifests itself at all levels of the organization of living matter, is ... .

4. The creators of the low-temperature theory of the origin of protobiopolymers - ... .

5. Pre-cellular formations that possessed some properties of cells: the ability to metabolism, self-reproduction, etc., - ....

Part C Give a short answer to the question.

1. What role did the study of meteorites play in the development of the theory of the origin of life?

2. What is racemization and chirality?

3. Why was water in the liquid phase a necessary condition for the origin of life?

4. What was Stanley Miller's experience? What was the gas composition of the "atmosphere"?

5. What are the main stages of studying the question of the origin of life on Earth?

AnswersOption 1 Part A : 1d, 2a, 3c, 4a, 5d, 6b, 7b, 8d, 9d, 10d,b,c,a.

Part B : 1 - creationism; 2 - prokaryotes; 3 - coacervate; 4 - A.I. Oparin; 5 - sexual process.

Part C. 1. Living and non-living matter consist of the same chemical elements, physical and chemical processes with their participation proceed according to general laws.

2. Oxygen is a strong oxidizing agent and all newly formed organic molecules would be immediately oxidized.

3. The "primary ocean" in this experiment corresponded to a flask with boiling water.

4. The main problem of the transition from chemical to biological evolution is to explain the emergence of self-reproducing biological systems (cells) in general and the genetic code in particular.

5. The main provisions of Oparin's theory:

Life is one of the stages in the evolution of the Universe;
- the emergence of life is a natural result of the chemical evolution of carbon compounds;
- for the transition from chemical to biological evolution, the formation and natural selection of integral, isolated from the environment, but constantly interacting with it, multimolecular systems are necessary.

Option 2 Part A : 1b,d, 2a, 3b, 4b, 5d, 6a, 7b, 8d, 9a, 10a,d,c,b.

Part B : 1 - photosynthesis; 2 - protobionts; 3 - coacervation; 4 - J. Bernal; 5 - genetic code.

Part C . 1. In 1953, S. Miller created an experimental setup in which the conditions of the primary Earth were simulated and molecules of biologically important organic compounds were obtained by abiogenic synthesis. "Lightning" in this experiment was imitated by high-voltage electric discharges.

2. If the mass of the planet is more than 1/20 of the mass of the Sun, intense nuclear reactions begin on it, which raises its temperature, and it begins to glow with its own light.

3. To the initial stage of the biochemical evolution of the Earth.

4. For the emergence of life, the following basic conditions are necessary:

The presence of certain chemicals (including water in the liquid phase);
- availability of energy sources;
- restorative atmosphere.

Additional conditions may be the mass of the planet and a certain level of radioactivity.

5. Panspermia - bringing the "seeds of life" to Earth from space. Supporters: J. Liebig, G. Helmholtz, S. Arrhenius, V.I. Vernadsky.

Option 3 Part A : 1 b, d, 2a, 3a, 4c, 5d, 6a, 7b, 8a, 9b, 10 b, c, a, d.

Part B : 1 - abiogenic synthesis; 2 - microspheres; 3 - self-reproduction; 4 - S. Fox; 5 - enzymes.

Part C . 1. When burning wood, all the energy released is dissipated in the form of light and heat. When glucose is oxidized in cells, energy is stored in macroergic bonds of ATP.

2. There are three main approaches to the problem of the origin of life:

There is no problem, because life was either created by God (creationism), or has existed in the universe since its inception and spreads randomly (panspermia);
- the problem is insoluble due to insufficient knowledge and the impossibility of reproducing the conditions in which life arose;
- the problem can be solved (A.I. Oparin, J. Bernal, S. Fox, etc.).

3. Carbon is tetravalent, capable of forming stable compounds with double and triple bonds, which increases the reactivity of its compounds.

4. In 1953, S. Miller created an experimental setup in which the conditions of the primary Earth were simulated and molecules of biologically important organic compounds were obtained by abiogenic synthesis.

5. Atoms --> simple chemical compounds --> simple bioorganic compounds --> macromolecules --> organized systems.

Option 4 Part A : 1b,d, 2a, 3b, 4d, 5d, 6a, 7c, 8d, 9d, 10b,a,d,c.

Part B : 1 - eukaryotes; 2 - genetic code; 3 - self-reproduction; 4 - K.Simonescu, F.Denesh; 5 - protobionts.

Part C . 1. Analysis of the chemical composition of meteorites showed that some of them contain amino acids (glutamic acid, proline, glycine, etc.), fatty acids (17 types). Thus, organic matter is not exclusively belonging to the Earth, but can also be found in space.

2. Racemization is a reaction of interconversion of D- and L-forms of any stereoisomer; chirality - the existence of two or more mirror asymmetric stereoisomers of a chemical compound.

3. Organisms are made up of 80% or more water.

4. In 1953, S. Miller created an experimental setup in which the conditions of the primary Earth were simulated and molecules of biologically important organic compounds were obtained by abiogenic synthesis.

The gas composition of the "atmosphere": methane, ammonia, water vapor, hydrogen.

5. From ancient times to the experiments of F. Redi - the period of universal faith in the possibility of spontaneous generation of the living; 1668-1862 (before the experiments of L. Pasteur) - experimental clarification of the impossibility of spontaneous generation; 1862-1922 (before AI Oparin's speech) - philosophical analysis of the problem; 1922-1953 - development of scientific hypotheses about the origin of life and their experimental verification; from 1953 to the present - experimental and theoretical studies of the transition paths from chemical evolution to biological.

Note

Part A is worth 1 point, Part B is worth 2 points, and Part C is worth 3 points. The maximum number of points for the control work is 35.

Grade 5 : 26-35 points; grade 4 : 18-25 points; grade 3 : 12-17 points; grade 2 : less than 12 points.

"ORIGIN OF LIVING BEINGS"

IN In the Middle Ages, people willingly believed that geese originated from fir trees, and lambs are born from the fruits of a melon tree. The beginning of these ideas, called "The Theory of Spontaneous Generation", was laid by the ancient Greek philosopher Aristotle. In the 17th century F. Redi suggested that the living is born only from the living and there is no spontaneous generation. He put a snake, a fish, an eel and a piece of beef in four jars and covered them with gauze to keep the air out. Four other similar jars he filled with the same pieces of meat, but left them open. In the experiment, Redi changed only one condition - whether the jar was open or closed. Flies could not get into a closed jar. After some time, worms appeared in the meat lying in open (control) vessels. No worms were found in closed jars.

In the 19th century A serious blow to the theory of spontaneous generation was dealt by L. Pasteur, who suggested that life is introduced into nutrient media along with air in the form of spores. The scientist designed a flask with a neck similar to a swan's neck, filled it with meat broth and boiled it on a spirit lamp. After boiling, the flask was left on the table, and all room dust and microbes in the air, easily penetrating through the opening of the neck inside, settled on the bend without falling into the broth. The contents of the flask remained unchanged for a long time. However, if the neck is broken (the scientist used control flasks), then the broth quickly became cloudy. Thus, Pasteur proved that life does not originate in the broth, but is brought from outside along with air containing fungal spores and bacteria. Consequently, scientists, putting their experiments, refuted one of the most important arguments of the supporters of the theory of spontaneous generation, who believed that air is the “active principle” that ensures the emergence of living things from non-living things.

C2. Fill in the table "Comparative characteristics of the experiments of F. Redi and L. Pasteur" the columns indicated by the numbers 1, 2, 3. When completing the task, it is not necessary to redraw the table. It is enough to write down the number of the column and the content of the missing element.

COMPARATIVE CHARACTERISTICS OF THE EXPERIMENTS

F. REDY AND L. PASTEUR

C3. Using the content of the text "Comparative characteristics of the experiments of F. Redi and L. Pasteur" and knowledge of the course, explain what meat and meat broth are in the described experiments and why they were needed.

C3. The correct answer must contain the following elements:

1) Meat and meat broth - nutrient media.

2) Meat is a medium for the development of fly larvae.

3) Meat broth - an environment for the development of bacteria and fungal spores.

"Concepts of the origin of life" - Problem. primary genetic material. The main difficulty of the hypothesis. Problems in modern science. biochemical evolution. Degree of order. The theory of panspermia. Archbishop Asher. RNA world. Interaction. There are many theories about the origin of life. French scientist. Italian biologist. Basic postulates of the theory of biochemical evolution. The idea of ​​spontaneous generation. Founder of the theory of panspermia.

"The problem of the origin and essence of life" - Natural history approach. Oparin. The concept of a steady state. DNA molecules. The human body weighing 70 kg contains 45.5 kg of oxygen. Chirality property. Creationism. Viruses. MessengerRNA. Anaxagoras. The concept of panspermia. The idea of ​​spontaneous generation. Basic provisions. Symposia on the origin of life. Biopolymers. The main merit of Oparin. The concept of biochemical evolution.

"How life on Earth arose" - The concept of biogenesis. Changes in the Earth's atmosphere. L. Pasteur. Van Helmont. Theory of a steady state. spontaneous generation of life. Origin of life on Earth. Theory of A.I. Oparina. F. Redi. Vitalism. L. Spallanzani. Panspermia. Life in the Earth. Natural origin of life. Experience of S. Miller. Theories of the origin of life. Microorganisms. Earth's atmosphere. Creationism. Theory of biochemical evolution.

"Concepts of the origin of life on Earth" - Radiation panspermia. Cell. Evolution theory. Emergence scheme. Soviet biochemist. Reverse directional panspermia. The germs of life. Experiments on reproduction of amino acids. Chemist Stanley Miller. Plant cell. The theory of panspermia. Creationism. What is life. Vernadsky. Paracelsus. Chemical elements. The living content of the cell. Polypeptides. Theory of spontaneous generation. Formaldehyde. A modern view of the origin of life.

"Theories of the emergence of life" - Organic compounds. Coacervat. Stages of life formation according to Oparin. Organisms are different from non-living things. The hypothesis of biopoiesis. biogenic way. Van Helmont. Theory of biochemical evolution of Oparin. The hypothesis of spontaneous origin of life on Earth. Steady State Hypothesis. French microbiologist Louis Pasteur. The hypothesis of biochemical evolution. Panspermia hypothesis. What is life. protein properties.

"The oldest organisms on Earth" - The oldest organisms. Brachiopod type. List of temporary divisions. What period are we living in? Similarities. Similarities and differences. Equipment. contemporary representatives. Jan Baptist Van Helmont. The theory is evolutionary. Representatives of the class of bivalve molluscs. Birth of life. Comb lock. Trilobite class. Class Bivalve Molluscs. Geological table. Theory of divine origin.

Terminology

1. Nebula- a large accumulation of gas-dust matter in the universe.

2. Galaxy a star and its surrounding planets.

3. star system- a system of stars with planets surrounding them, developing from one nebula.

4. Planet- a celestial body moving in a close to circular orbit around a star, glowing with reflected light.

5. Abiogenic synthesis- the formation of organic molecules from inorganic outside living organisms.

6. Energy- a general quantitative measure of the momentum of matter.

7. Solution- homogeneous mixtures of two or more substances distributed in a solvent.

8. Coacervation - separation of the HMS solution into phases with higher and lower concentrations of molecules.

9. coacervatus- liquid bubbles surrounded by protein films.

10. Adsorption– absorption of a substance from a liquid medium by the surface of a solid body.

The question of the origin of life on Earth, and probably also on other planets of other star systems, has worried man since he began to realize himself as a man, began to know himself and the world around him. The first attempts at a theoretical solution to the problem date back to ancient times and bear the imprints of those eras and views. Since ancient times, there have been two points of view on this issue: one asserts the possibility of the origin of living things from non-living things - this is the theory of abiogenesis, the other - the theory of biogenesis - denies the spontaneous generation of life. Modern views only allow us to put this dispute on a scientific basis and thereby substantiate the correctness of the theory of abiogenesis.

Representations of ancient and medieval philosophers

The general level of knowledge in the ancient world was low, the views were fantastic. Ignorance of the methods of reproduction of organisms was the reason that it was considered possible for the emergence of living beings from dead remains, or inorganic substances. These views were supported by the church. The discovery of the microscope expanded the understanding of the structure of organisms, the theory of the origin of the living from the non-living was rejected. The experiments of the Italian Redi (mid-17th century) proved that all living things come from living things. However, the theory of spontaneous generation of the living from the non-living existed for a long time in the ears of scientists. The experiments of the Frenchman L. Pasteur finally dispelled this theory. Based on the work of Pasteur, methods of sterilization and preservation were developed. This happened in 1870.

Subsequently, this question was transferred to the cell, and microorganisms were no longer considered. Simultaneously with the work of Pasteur, the theory of the eternity of life arose. According to Richter's theory, in 1865 life on Earth was brought from other planets. This theory does not reveal the essence of the origin of life, it only tries to explain its appearance.

A special place in the solution of the problem belongs to materialistic theories. The key issue here is the difference between living and non-living. Scientists take the formation of protein compounds as the basis for the origin of living things. According to the theory of the Englishman Ellen in 1899. The first appearance of nitrogenous compounds on Earth is dated to the period when water vapor condensed into water and covered the surface of the planet. The water was saturated with salts, which are of great importance for the formation and activity of protein. In this hot solution, in the presence of ultraviolet, electrical discharges, a large amount of carbon dioxide, the birth of living things began, which subsequently went through a long evolutionary path.

Investigating the question of the origin of living things, one should simultaneously understand the processes that take place during the formation of the planet. The answer to these questions is given by astronomy and chemistry. The main method of space exploration is spectroscopy. Analysis of the light emitted by stars provides rich information about their chemical composition. From the end of the 19th century 2 million registered. spectra of 15 thousand stars and the Sun. The conclusion is that the same chemical elements exist everywhere and the same physical laws are observed. The formation of the planet.

The most common element is hydrogen (H-H, H-He). In a universe formed from hydrogen, stars are formed as the primary substance. The main nuclear reaction is the fusion of hydrogen nuclei and the formation of a helium atom and the release of energy. This energy drives the universe. According to the law of mass conservation, the energy released during formation is converted into radiation energy. Further interaction of elements leads to the formation of other chemical elements. These reactions are expressed in the formation of more complex molecules and their aggregates - dust particles. They form accumulations of gas and dust matter in space. For example, the giant nebula in the constellation Orion. Its diameter is 15 light years, the amount of dust is enough to form 100 thousand stars the size of the Sun. The Milky Way Nebula has a diameter of 100,000 light years. The Orion Nebula is the closest one to us, at a distance of 1500 light years. The Earth and other planets of the solar system were formed from a gas and dust cloud 4.5 billion years ago. Despite the common origin of the planets, life appeared only on Earth and reached exceptional diversity. Cosmic and planetary conditions were necessary for the emergence of life on Earth. First, it is the optimal size of the planet. Secondly, movement in a circular orbit provides constant heat. Thirdly, the constant radiation of the luminary. All these conditions were satisfied by the Earth, on which, about 4.5 billion years ago, conditions were created for a higher level of development of matter and its evolution towards the emergence of life.

Modern ideas about the origin of life. All modern ideas about the origin of life on Earth are based on the recognition of the abiogenic, i.e. non-biological origin of organic substances from inorganic molecules. This is the opinion of the Russian scientist A.I. Oparin (1924).

Chemical evolution

In the early stages, the Earth had a very high temperature. As it cooled, the heavy elements moved towards its center, while the light ones remained on the surface. Metals were oxidized and there was no free oxygen in the atmosphere. It consisted of H 2 , CH 4 , NH 3 , HCN and was of a reducing nature. This served as a prerequisite for the emergence of organic substances in a non-biological way. Until the early 20th century, it was believed that they could only occur in the body. In this regard, they were called organic, and substances - minerals, inorganic. In 1953 it was proved that by passing a current through a mixture of gases H 2 , CH 4 , NH 3 , HCN in the absence of oxygen, a mixture of amino acids was obtained. Subsequently, many organic compounds were obtained abiogenically. All of them were subsequently discovered in space.

More than 4 billion years ago, the "Miller flask" was the entire globe. Volcanoes erupted, lava flowed, steam swirled, lightning flashed. As the planet cooled, water vapor condensed and rained down on the planet over millions of years. A primary ocean was formed, hot and saturated with salts, in addition, the formed sugars, amino acids, and organic acids got there. As the climate softened, the formation of more complex compounds became possible, resulting in the appearance of primary biopolymers - polynucleotides and polypiptides.

The primordial ocean contained various organic and inorganic molecules in soluble form. Their concentration constantly increased and gradually the waters became a "broth" of nutrient organic compounds. Each molecule has a certain structural organization: some are dissociated, some have hydrated shells. Organic molecules have a large molecular weight and a complex structure. Molecules surrounded by an aqueous shell are combined to form high-molecular complexes - coacervates. In the primordial ocean, coacervate drops absorbed other substances, either collapsed or grew larger. As a result, the drops became more complex and adapted to external conditions. Among the coacervates, the selection of the most stable forms began. There were differences between the chemical composition of the internal and external environment. As a result of chemical evolution, those forms have been preserved that, when decomposed into daughter ones, did not lose their structural features. This is the ability to reproduce itself. In the process of evolution, the connection of nucleic acids and protein molecules led to the emergence of the genetic code. This nucleotide sequence served as information for the sequence of amino acids in a protein molecule. (Reproduction of their own kind). Gradually, the lipid layers around the coacervates were transformed into an outer membrane. This predetermined the path of further evolution. The formation of primary cellular organisms marked the beginning of biological evolution.

The emergence of prokaryotes

The selection of coacervates continued for about 750 million years. As a result, nuclear-free prokaryotes appeared. According to the method of solution, they were heterotrophs - they used the organic matter of the primary ocean. In the absence of atmospheric oxygen, anaerobic metabolism proceeded in them. He is ineffective. Gradually, food supplies in the ocean were depleted. The competition for food has begun.

Organisms capable of using solar energy for the synthesis of organic matter turned out to be in a more advantageous position. This is how photosynthesis came about. This led to the emergence of a new power source. Then photosynthetic organisms learned to use water as a source of hydrogen. The assimilation of carbon dioxide in them was accompanied by the release of oxygen and the incorporation of carbon into organic compounds. (Today, ocean surface prokaryotes produce up to 78% of renewable oxygen.)

The transition from the primary atmosphere to the oxygen environment is a very important event. In the upper layers, an ozone screen is formed, a more favorable, oxygen type of metabolism appears. On Earth, new forms of life began to emerge with a wider use of the environment.

Emergence of eukaryotes

Eukaryotes arose as a result of symbiosis of various prokaryotes. This is how the ancestors of the primitive living flagellate protozoa arose. Symbiosis of flagellates with photosynthetic gave algae or plants.

The possibilities of unicellular organisms in the development of their habitat were limited. Multicellular organisms appeared 2.6 billion years ago. The basis of modern ideas about the origin is explained by the theory of phagocytella by I.I. Mechnikov. Multicellular organisms evolved from colonial flagellates. They exist even now. These colonies have evolved into a simple but complete organism.

Thus, the emergence of life on Earth is associated with a long process of chemical evolution. The formation of the membrane - the shell contributed to the beginning of biological evolution. Both the simplest and the most complex have a cell in their structural organization.

Control questions

1. The history of ideas about the origin of life.

2. Works of L. Pasteur.

3. Theory of the eternity of life.

4. The formation of inorganic substances and the formation of the planet.

5. Theory of A.I. Oparina.

6. Biological evolution.

7. The emergence of the first multicellular.