Development of ideas about the origin of life presentation. Modern ideas about the origin of life on Earth. the process of transforming inanimate nature into living
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KSU "Zyryanovsk Agricultural College" ORIGIN AND INITIAL STAGES OF LIFE ON EARTHslide 2
Lesson objectives: Educational: students should know the conditions and stages of the emergence of life on Earth in the course of biochemical evolution. - understand that life, as a way of existence, is unique - be able to compare and analyze various hypotheses, correctly identify them according to their essential characteristics. - apply the acquired knowledge when working with diagrams, tables Developing: to develop - the ability to compare, analyze, draw conclusions; skills in working with information, tables, diagrams. Educators: students should: - show such qualities as composure, responsibility, attentiveness. - develop interest and positive attitude to biological science and the search for a comprehensive theory on the problem of the origin of life on Earth.slide 3
“Oh, solve for me the riddle of life, the painful ancient riddle, over which so many heads, heads in hats painted with hieroglyphs, heads in turbans and black berets, heads in wigs and thousands of other poor human heads...” H. Heine.slide 4
Problem questions How did life originate on Earth? What are the views and hypotheses about the origin of life on Earth? Which one is the most persuasive?slide 5
Life is ... "nutrition, growth and decrepitude" Aristotle "persistent uniformity of processes with a difference in external influences" G. Treviranus "a set of functions that resist death" M. Bisha "chemical function" A. Lavoisier "complex chemical process" I.P. Pavlov "special, very complex shape motion of matter "A.I. Oparinslide 6
“Life is a mode of existence of protein bodies, the essential point of which is the constant exchange of substances with the external nature surrounding them, and with the cessation of this exchange of substances, life also ceases, which leads to the decomposition of protein” Friedrich Engels (November 28, 1820 - August 5, 1895, London) - German philosopher, one of the founders of Marxism, friend, like-minded and co-author of Karl MarxSlide 7
“Living bodies that exist on Earth are open, self-regulating and self-reproducing systems built from biopolymers - proteins and nucleic acids»Mihai L Vladi Mirovich Volkenstein (October 10 (23), 1912, St. Petersburg - February 18, 1992, Moscow) - Soviet physical chemist and biophysicist, corresponding member of the Russian Academy of Sciences.Slide 8
“Life is a phase-separated form of existence of functioning autocatalysts capable of chemical mutations and having undergone a rather long evolution due to natural selection” Valenti n Nikolaevich Parmon (born April 18, 1948, Brandenburg) is a Russian scientist. Specialist in the field of catalysis and photocatalysis, chemical kinetics.Slide 9
Criteria are the basic properties of living organisms. - the complexity and high degree of organization of living beings - the metabolism and energy. - unity chemical composition- discreteness (discontinuity, separateness). – irritability – growth of organisms – development. - self-reproduction (reproduction). - the ability to self-regulate.slide 10
Life is a complex of properties: metabolism, the ability to grow and develop, reproduce their own kind, irritability and mobility.slide 11
A hypothesis is an assumption with insufficient evidence. Theory - views that have solid evidence. Biogenesis is a scientific theory that explains the emergence of life only as a result of the vital activity of living organisms. Abiogenesis is a scientific theory that explains the origin of life through the gradual formation of organic compounds from inorganic ones. Protobionts are primitive organisms that first appeared on Earth. Coacervates are clots in the form of a multimolecular drop with an outer thin water shell. Evolution is the irreversible historical development of living nature. Autotrophs - (ancient Greek αὐτός - itself + τροφή - food) - organisms that synthesize organic substances from inorganic ones. Heterotrophs - (ancient Greek ἕτερος - “other”, “different” and τροφή - “food”) - organisms that use only or mainly organic substances produced by autotrophs for nutrition. New conceptsslide 12
Both the Earth and life are created by the Supreme Mind (God) ABIOGENESIS Life arose repeatedly as a result of spontaneous generation. The main points of view on the origin of life on Earth BIOGENESIS Living organisms appeared on Earth 3.5 billion years ago in the course of biochemical evolution. Life is brought from space along with meteorites, then evolution. The earth has existed forever, has always been able to support life; if changed, then very little (the hypothesis of eternal life)slide 13
Hypotheses of the origin of life № Name of the hypothesis Proponents of the hypothesis Ideas about the origin of life 1. Creationism - Divine creation of the world Creationism - lat. wordcreatio - creationslide 14
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Life is created by the Supreme Mind (God, the Creator) Creationism Hypothesis However, the victory of the theory of biogenesis has led to another problem. For the emergence of one living being, another living organism is needed. Where did the first living organism come from? In other words, how and when did life first arise on Earth? There are many "white spots" in the theories of the formation of the Earth and the solar system, the emergence of life on Earth.slide 16
The hypothesis of Panspermia (from the Greek "pan" - everything, "sperma" - seed) Anaxagoras (500-428 BC) - ancient Greek philosopher, mathematician and astronomer, founder of the Athenian philosophical school. In the 5th century BC. expressed the idea of cosmic seeding - panspermia: life arose from the "seed" that exists "always and everywhere", the "embryos of life" were brought to Earth by meteorites or space dust... However, the victory of the theory of biogenesis led to another problem. For the emergence of one living being, another living organism is needed. Where did the first living organism come from? In other words, how and when did life first arise on Earth? There are many "white spots" in the theories of the formation of the Earth and the solar system, the emergence of life on Earth.slide 17
Eustace Liebig (1803-1873), German chemist, put forward and formulated the panspermia hypothesis: life is transferred from planet to planet by meteorites. The "seeds of life", getting to a new planet and finding favorable conditions here, multiply, giving rise to evolution from the simplest forms to complex ones. Panspermia hypothesis Proponents of the panspermia hypothesis: Vernadsky Vl. Iv. (1863-1945) Svante Arrhenius (1859-1927)slide 18
The Steady State Theory, or… Considered the hot masses of the emerging globe as gigantic living organisms with their own special metabolism. The cooled masses fell out of the circle of life and constituted inorganic nature. Hypothesis of Eternal Life In 1880 put forward by the German scientist W. Preyer.slide 19
Vitalism (from lat. vitalis - vital, life-giving, alive) "Life force" is present everywhere, just "breathe" it, and the inanimate becomes aliveslide 20
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In the Middle Ages, it was “successful” to observe the birth of living beings, such as insects, worms, eels, mice, in the decomposing or rotting remains of organisms. It was believed that there are trees, from the fruits of which, falling to the ground, birds are formed, from those that fell into the water, fish . Spontaneous generation of lambs Spontaneous generation of Bernakel geese SELF-GENERATION OF LIFEslide 22
The Belgian physician Van Helmont (1579 - 1644) offered a recipe for the birth of mice: “Put grain in a pot, plug it with a dirty shirt and wait. What will happen? After 21 days, mice will appear: they will be born from the fumes of caked grain and a dirty shirt ... "Hypothesis of spontaneous generation Aristotle (384 - 322 BC), who is called the founder of biology, wrote that "frogs and insects start in damp soil ... "In Europe until the middle of the XVI century. obscurantism prevailed, an intolerant attitude towards the development of the sciences, especially the natural ones. At this time, alchemy flourished. Among the alchemists there were many naive and ignorant people, but there were others - excellent scientists, whose names went down in history. Among them are the Belgian physician Van Helmont and the Swiss physician Paracelsus, the greatest reformer of the Renaissance, the father of modern medicine. Alchemists dreamed of finding the philosopher's stone and getting gold. But there were others... Having set their tables with jars, retorts, having built distillation cubes and other devices, they boiled, distilled, insisted, filtered... Everything that came to hand was poured into flasks. We tried our best. Some called on God for help, others were ready to give their souls to the devil, just to see how some kind of tadpole, frog, or mouse would wrap in a flask. Alas, nothing worked. Apparently, the essence of the recipe. Van Helmont took over.slide 23
“Take a well-known human fluid (urine), leave it to rot first sealed in a pumpkin, then in a horse stomach for 40 days, until it begins to live, move and swarm, which is easy to notice ... then daily, in secret and carefully, with prudence, feed it human blood and kept for 40 weeks in constant and uniform warmth of the stomach, then a real living child will occur, having all members, like a child born from a woman, but only very vertically challenged ". The alchemists called such a man from a test tube HOMUNCULUS (homunculus) Theophrastus Paracelsus (1493 - 1541) The Swiss doctor, alchemist, wrote: Paracelsus also offered his recipe. Messing around with getting mice, frogs, scorpions is too small. If we get down to business, then so that a homunculus appears in a test tube. You, who have not studied Latin, do not understand this word. But you have heard the word "homo" more than once - a person. The diminutive of the word "man" is "little man", and in Latin - "homunculus". But "homunculus" was a fantastic creature that was supposed to be created in the laboratory, even if it was a giant. The homunculus is a memory of visionaries who dreamed of creating the living from the inanimate. The great magician in his laboratory, dimly lit, with vaulted ceilings, tables filled with flasks of colored liquids, stills and retorts. On the walls are bundles of bats, mangy, moth-eaten stuffed animals and birds. Under the ceiling is a crocodile. He writes the recipe: “Take a known human fluid. (urine) leave it to rot first in a sealed gourd, then in a horse's stomach for forty days, until it begins to live, move and swarm, which is easy to notice. What happened is not at all like a person, it is transparent and without a body. But if then every day, secretly and carefully, with prudence, nourish it with human blood and keep it for forty weeks in the constant and even warmth of a horse's stomach, then a real living child will occur, having all members, like a child born from a woman, but only very small. growth." It’s easy to pour the “known human liquid” into a pumpkin, and then pour it into a horse’s stomach, too. But to “nourish carefully and with prudence” that invisible and transparent thing that should be swarming in a rotting liquid is not at all simple. There are so many loopholes in the recipe that you can always get away with the answer. Let's imagine that an alchemist student enters his laboratory, bows respectfully before the Teacher and speaks with trembling. Student. Teacher, I did everything that is written in your recipe. But I didn't succeed! Paracelsus. Yes? And did you do it right? Student. Yes, yes, Teacher. Paracelsus. No, no and NO! You didn't follow all the instructions! Were you prudent and careful? Did you let the liquid rot enough? Did you pour it from the pumpkin into your stomach in time? Have you kept the secret? The student lowers his head. Yes, about the secret - he could not resist, he boasted in the tavern to his comrades that the “unborn” little man would soon appear in his laboratory. Paracelsus. Well? Confess! Student. You are right, Teacher. Again, the unfortunate student fills the gourd and waits. Every day he looks: rots or does not rot. At the right time, he pours the rotten liquid into the horse's stomach, turning his nose to the side. Smells very unpleasant. Yes, Paracelsus deftly fooled everyone. There were new "creators" of fantastic stories. No one knew where worms, flies, frogs, snails come from. Why do they sometimes appear in large numbers? Nobody saw their birth, their eggs, development. Here is the conclusion: they spontaneously originated from dirt, rotting parts of plants, animals, and you never know what. However, there were skeptics who believed nothing and no one. Sometimes they tried to protest. But... (pause) the authority of the Greek scientists and the wisest of them, Aristotle, was unshakable. Who dares to contradict him! Just then, an ominous cry was heard.slide 24
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Redi took 4 pots with a wide mouth, put a dead snake in one, some fish in another, eels in the third, a piece of veal in the fourth, tightly closed. Then I placed the same in 4 other pots, leaving them open. Soon the meat and fish in the open vessels became wormy, and flies could be seen freely entering and flying out of the vessels. There was not a single worm in the closed pots, although many days had passed since the experiment was begun. Experiments by Francesco REDI, 1668 “Flies are not born from rotting meat. Worms don't spawn on their own in rotting meat. They hatch from testicles laid there by flies…” 1668. Redi took four wide-mouthed pots, put a dead snake in one of them, some fish in another, Arno eels in the third, a piece of veal in the fourth, closed them tightly and sealed. Then he placed the same in four other pots, leaving them open. Thus, the scientist decided to control the course of his experiment. Outside it was the middle of June. Soon the meat and fish in the open vessels became wormy, and flies could be seen freely entering and flying out of the vessels. There was not a single worm in the closed pots, although many days had passed since the experiment was begun. Redi: "Flies are not born from rotting meat. Worms don't spawn on their own in rotting meat. They come out of the testicles laid there by the flies.” It was a brilliant experiment. Redi proved the impossibility of spontaneous generation of flies. His data supported the idea that "life can only arise from a previous life." By striking at the theory of abiogenesis, Redi laid the foundation for the theory of biogenesis.slide 26
Lazzaro Spallanzani, Italian abbot, mathematician and naturalist: “... One has only to seal the bottles and boil the infusion for an hour - and not a single microbe will appear there, no matter how long the infusion stands ...” Ideas of biogenesis: Ideas of abiogenesis Georges-Louis Leclerc, Comte de Buffon, French writer, naturalist, biologist, mathematician, artist: "... Microbes are born from tinctures and gravies! .." ... And microbes must have parents! .. 1729 - 1799 1707 - 1788 Scientists divided into two camps on the origin of microorganisms , some argued that microorganisms spontaneously generated, others argued that spontaneous generation was impossible. The French Buffon and the Irish Needham were representatives of one camp, the other was represented by the Italian abbot Lazzaro Spallanzani.slide 27
I can make infusions from peas and almonds, from wallflower leaves or carnation flowers. And the composition of the animals will be the same everywhere. But only on condition that all infusions are prepared on the same water. A simple conclusion follows from this: animalcules get along with water. There is nothing surprising. Indeed, in nature, these crumbs live in water: swamp, pond, lake, sea and even well. And when they dry out, they die. Refutation of spontaneous generation… M.M. Terechovsky 1740-1796 Spallanzani's ally was the Russian scientist Martyn Matveyevich Terekhovsky. In dozens of books one can read about Spallanzani's dispute with Buffon and Needham, but one rarely comes across the name of Terekhovsky, our compatriot, who experimentally proved the impossibility of spontaneous generation almost simultaneously with Spallanzani. At the University of Strasbourg, Terekhovsky wrote and defended the work "Zoological and physiological dissertation on Linnaeus's pouring chaos." “Pouring Chaos” is a name that is not very clear to us. "Chaos" in his system of animals, Linnaeus called the section to which he attributed the most diverse creatures that have one common property - the smallest sizes. For example, ciliates, the very name of which comes from the Latin "infusion, liqueur". Terekhovsky, unlike Spallanzani, did not argue with Buffon. He worked only with ciliates and flagellates, which after a while appear in infusions of seeds, fruits and herbs. But where do they come from? Terekhovsky. The reason is the water. I can make infusions from peas and almonds, from wallflower leaves or carnation flowers. And the composition of the animals will be the same everywhere. But only on condition that all infusions are prepared on the same water. A simple conclusion follows from this: animalcules get along with water. There is nothing surprising. Indeed, in nature, these crumbs live in water: swamp, pond, lake, sea and even well. And when they dry out, they die. There was another way for these crumbs to get into the infusions - air. However, the doctor decided that such a probability was too small. The water was the most suspect. Terekhovsky began to experiment with water. Terekhovsky. To begin with, I will take clean water - raw and boiled, pour it into vessels and leave them open. I'll see what happens. So, in a vessel with raw water, animals appeared, in boiled water they are not. I will add raw water to a vessel with boiled water. Now, now “cute crumbs” have appeared in it. Therefore, they get into infusions with raw water! I will also do the following experiment: I will heat one jar of animals above 35 ° C, and freeze the other. What will happen? Animalcules died in both banks. Now I will leave the vessels with cooled and melted water for a long time. Animalcules did not appear! So, I’ll boil the grass, fill it with raw and boiled water. Now the animals have appeared in a jar of raw water. And there are none in the boiled jar, although it has stood for many days. And if I make tea, why not infusion? But no one got into it either. There is no spontaneous generation! Terekhovsky did many experiments. The result was the same. Animalcules appeared in infusions made with raw water, and when raw water was added to the broth after cooling. Now you and I know what could have happened in a different way - protozoan cysts could get into the vessels with boiled water from the air. But this did not happen: the vessels stood in the rooms, and the cysts of the protozoa, in contrast to the spores of microbes, in clean air very little - 1-2 per cubic meter of air. However, at the time of Terekhovsky, they simply did not know anything about protozoan cysts, and for his time he convincingly proved that animalcules do not originate in infusions. The Paris Academy of Sciences decided to put an end to these disputes and appointed a prize for the final experimental solution of the issue, having discussed that "no ambiguities in the setting of experiments should obscure their results." Pasteur, the famous "germ hunter", having learned about the competition, set to work. Pasteur. Fools! They think that if there are no germs in the air, then they are not there. No matter how! I'll prove it to them! It's not difficult either. I'll take a glass tube and put a piece of cotton wool in it. I will attach a pump to one end of the tube, put the other out of the window and begin to suck in outside air. Four hours passed, the cotton wool in the tube darkened. I will wash it in a watch glass and wring it out over another. I will do this operation several times. The fleece became clean, all the dust was washed off it. Well, let's see, let's see what is in the flush from the fleece. I put a drop of water on a glass slide and look at its contents under a microscope. There are fungal spores, mold spores, microbes and their spores! Now it was necessary to learn how to catch microbes. Pasteur is an excellent microbiologist. The scientist poured nutrient solutions into cones and boiled them. Then he heated the neck of the flask, pulled it into a long tube and sealed the tip. With such a flask it was possible to start hunting. Going out into the yard, Pasteur broke off the soldered tip. Air rushed into the flask and brought microbes and their spores into it. After that, Pasteur sealed the neck again. Pasteur. So it is, the microbes that got into the flask multiplied. This can be seen from the cloudy cloud formed on the surface of the broth. Oh, these are clouds of microbes! Pasteur did not stop there. Now he had to figure out which air had more germs. With flasks in his hands, he wandered through the Parisian garbage dumps. Then he stumbled over the roots and stumps of trees in the forest, elms in swamps, wandered along the seashore, climbed high mountains, even climbed the glaciers of Mont Blanc. Everywhere he opened and sealed flasks. And then in the laboratory he was engaged in bookkeeping: he kept a careful record of microbes under a microscope. Pasteur. Well, it is, germs are everywhere. True, in some places there are a lot of them, in others there are few. In the air of glaciers, they are the least. Yes, and not always I was able to catch a single microbe here. So the first part of the problem was solved - microbes and their spores were in the air everywhere and could get anywhere. But the second part was much more difficult - to prove that it is the microbes, getting into the flask from the air, that mislead the researchers. The well-known rule “Heat the air, kill the germs in it” is no good. Needham also argued that heated air is not suitable for life, so spontaneous generation does not occur in it. The air cannot be warmed up, which means that microbes can remain in it, and ... a fairy tale about a white bull begins. How to solve this problem? What barrier to put on the way of microbes into the flask? Pasteur was lucky. He met a man who gave good advice. This is how the famous "Pasteur flask" appeared. The neck in such a flask is elongated into a long tube and curved like the neck of a swan. Pasteur set up a new series of experiments: he poured into flasks various nutrient media (yeast solution with added sugar, sugar beet juice, pepper infusion, urine) prepared under normal conditions. Over the fire, he pulled the neck of the flask into a long tube, pulled the tip of the elongated neck down with tweezers, and then up. The result was a bend. The liquid boiled in the flask for several minutes. The steam during boiling escaped freely through the long narrow end of the flask. After the flask cooled down, the nutrient solutions remained clear. At first glance, it might seem that microbes could get into the cooling flask in the usual way - through the neck, along with air. In fact, all the dust and microbes from the air settle in the damp places of the bend of the tube and do not get to the nutrient solution. If, after several months of storage of the infusion in such an open flask, the curved neck is broken off, then various microorganisms will very quickly appear in the infusion. Pasteur. See? No spontaneous generation! The flask contains both nutrient solution and air! Where is your productive force? Where is spontaneous generation? Show it to me. Pouchet and his associates - two professors from Toulouse - stuffed sealed Pasteur flasks with boiled hay infusion into their pockets and climbed into the mountains. The results of the expedition showed that microbes always appeared in the flasks. Even in air samples taken on Mount Mladetta, which is much higher than Mont Blanc. Push. Mister Pasteur! So, is there spontaneous generation or not? Pasteur did not doubt the purity of his experiments and doubted the accuracy of the experiments of Pouchet and his supporters. To him who has experienced much different environments, I didn’t want to repeat all the work and also check the hay infusion. Why waste precious time on nonsense? Pasteur. Let the committee figure it out! And find Pushe's mistake. The Academy of Sciences decided in its own way. Commission? The commission has been appointed. But to understand Pouchet's experiments? Not! The solution is this: in the presence of the members of the commission, Pasteur and Pouchet must perform their experiments. Pouchet refused. Perhaps he doubted his research. There were also rumors that the commission found fault with the French scientist, preferring Pasteur in advance. What really happened, we don't know. But Pouchet refused, and the commission issued a verdict: Pasteur's experiments were convincing. However, 10 years later, in England, the doctor Bastian conducted a new series of experiments with hay infusion. Indeed, microbes appeared in the flasks every time, although the experimenter reproduced Pasteur's experiment exactly. So, was Pasteur wrong, was Pouchet right? Pasteur. I thought Pouchet had messed up something. But Bastian has a similar result... Still, something is wrong here! We need to find the reason. Pasteur solved this riddle as well. Both Pouchet and Bastian were wrong: there was no spontaneous generation in hay infusion. Microbes got into the infusion in this case, not from the air. They were present in the hay, from which the infusion was prepared. There is such a microbe - "hay stick". The spores of this microbe do not die when boiled, withstanding a temperature of 100 C. Therefore, simply boiled hay infusion is teeming with spores of hay bacillus. As long as the flask is sealed, there is no oxygen in it, microbes do not develop. But as soon as the neck of the flask is broken off, air enters it, and microbes begin to multiply. This is what Pouchet and Bastian observed. Pasteur found a hay stick and guessed how to kill it: you need to boil the infusion for at least 20 minutes at a temperature of 120 C and at high pressure in closed vessels. To achieve such conditions, Pasteur came up with what is now called the "autoclave". Autoclaves are now used to sterilize medical instruments. And then the objections of Pouchet and Bastian were refuted. Pasteur. My prize! And he got it. The dispute, which lasted hundreds of years, ended with the victory of the theory of biogenesis. This was in 1862.
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The purpose of the lesson: To form a system of knowledge among students about different views on the origin of life on Earth.
Lesson objectives:
I. Educational:
- Show the role of experiment in resolving scientific disputes about the origin of life.
- Learn to analyze the main scientific hypotheses about the origin of life.
II. Developing:
- Continue to develop the desire for independent cognitive activity.
- Continue the formation of formal-logical skills of explanation, concretization, definition, generalization.
III. Educational:
- Intellectual - to continue the formation of a scientific worldview.
- Ecological - consolidation of knowledge about the relationship of animate and inanimate nature.
- Moral - the formation of students' knowledge and beliefs about human responsibility for maintaining the integrity of the biosphere of our planet.
Motivation:
The origin of life on our planet is the subject of centuries-old discussions in which more than one generation of mankind participated. This is an interesting field of knowledge, which has scientific, philosophical and ideological significance, still attracts the attention of researchers in various fields.
The study of various theories about the origin of life on Earth is necessary for compiling a holistic view of the historical path of the development of wildlife, the formation of a scientific worldview.
Learners should know:
- The main provisions of theories about the origin of life;
- Modern ideas about the origin of life on Earth (the theory of biochemical evolution).
Learners should be able to:
- To uncover key provisions the main theories about the origin of life on Earth;
- Give a description of the experiments of F. Redi, L. Spallanzani, L. Pasteur, S. Miller, reveal their significance for solving the issue of the origin of life;
- To reveal the main provisions of modern ideas about the origin of life on Earth (theories of biochemical evolution);
- Formulate the main provisions of the theory of A.I. Oparin.
Lesson equipment:
- lesson plan;
- abstract;
- Handout;
- tasks for control;
- presentation;
- a laptop;
- multimedia projector;
- screen.
Interdisciplinary connections:
a) physics (device design, physical phenomena);
b) chemistry (composition of the atmosphere, chemical substances);
c) history (development of science);
d) philosophy (formation of scientific outlook);
e) foreign language(translation of terms).
Literature for the teacher:
- Sivoglazov V.I., Agafonov I.B. General biology 10-11. - M .: Bustard, 2005
- Sivoglazov V.I., Sukhova T.S., Kozlova T.A. General biology. A guide for the teacher. – M.: IRIS PRESS, 2004
- Sukhova T.S. Biology lesson. Developmental learning technology. – M.: Ventana-Graf, 2001
Literature for students:
1. Sivoglazov V.I., Agafonov I.B. General biology 10-11.– M.: Bustard, 2005
Lesson timeline:
1. Organizational moment
Greeting, checking those present according to the list, wishing successful work in class.
2. Control of the initial level of knowledge (standards of correct answers are indicated in brackets)
Goals:
- Determine the level of knowledge of students.
- Adjust the level of complexity of the presentation of new material.
1. By what main features (criteria) can a living object be distinguished from an inanimate one?
(The unity of the chemical composition of living organisms, metabolism, irritability, growth, reproduction, development, adaptability to the environment, self-regulation).
2. Where and when did the first living organisms arise? What were they like? (The first organisms appeared about 3 billion years ago in the aquatic environment, they were unicellular prokaryotes, fed on the organic matter of the ocean, anaerobes.)
3. What stages in the development of plants on Earth can you name? (unicellular, multicellular; the emergence of photosynthesis, the sexual process; access to land, the development of terrestrial vegetation.)
4. What stages in the development of animals on Earth can you name? (Single-celled, colonial, multicellular; the appearance of the sexual process; the appearance of invertebrates and vertebrates; access to land; complication in structure due to the terrestrial lifestyle.)
5. What substances are part of living organisms?
(Inorganic (water, mineral salts) and organic (amino acids, proteins, fats, carbohydrates, etc.))
3. Studying new material (explanation of new material is accompanied by a presentation, slide numbers are indicated in the text)
3.1. Formulation of the problem
Life has existed on Earth for billions of years. It fills all corners of our planet.
From ancient times to our time, a huge number of hypotheses about the origin of life have been expressed. The specificity of living things determines a number of questions that need to be answered when solving the problem of the origin of life:
- How did life originate and develop on our planet?
- How did the cell, the structural unit of life, come into being?
- How did all the substances and structures specific to living things come about?
- How was the existing metabolism formed? Etc.
We have to get acquainted with the hypotheses of the origin of life, analyze them and form an idea of how life arose and developed on Earth.
3.2. Development of ideas about the origin of life on Earth (slide number 1)
Since time immemorial, the origin of life has been a mystery to mankind. From the moment of its appearance, thanks to labor, a person begins to stand out among other living beings.
But the ability to ask yourself the question “where are we from?” a person receives relatively recently - 7-8 thousand years ago.
Until that time, man had difficulty separating himself from other animals (man was both a hunter and a kind of game), but gradually he began to delimit himself from nature with his inner spiritual world. The first primitive forms of belief in unreal, supernatural or divine forces arose already 35-40 thousand years ago.
3.3. The main theories of the origin of life on Earth (Slide #2)
According to this theory, life arose as a result of some supernatural event in the past, which most often means a divine creation. The idea of the creation of the world as a “creative act” of God arose, and this myth underlies all religions.
"These are the facts - living things can arise not only as a result of the mating of animals, but also the decomposition of the soil ... Some plants develop from seeds, while others spontaneously arise under the influence of the forces of nature from the decaying earth or certain parts of plants ..."
However, with the advent of Christianity, especially in the Middle Ages, the theory of spontaneous generation came under the yoke of the Church. She was considered an attribute of witchcraft and a manifestation of the devil. However, she continued to exist.
At the turn of the XVI-XVII centuries. Van Helmont (1579 - 1644) described an experiment in which he managed to get mice from dirty linen and wheat placed in a dark closet. Van Helmont considered human sweat to be the active beginning of the birth of a mouse. (Slide number 5)- to concept of biogenesis (from the Greek "bios" - life, "genesis" - origin). (Slide number 6)
In 1668 the Italian physician Francesco Redi (1626-1698) proved that the white worms found in meat are fly larvae; if meat or fish are closed up while they are fresh, and the access of flies is prevented, they, although they rot, will not produce worms. From this, F. Redi concluded that the emergence of the living only from the living). (Slide number 7) In 1765, Lazzardo Spallanzani (1729-1799) boiled meat and vegetable concoctions and immediately sealed them. A few days later, he examined the decoctions and found no signs of life. From this he concluded that heat destroyed all living things, and nothing new could arise. (Slide number 8)
J. Needham - supporter vitalism (from lat. vita - life), explained the negative results obtained by L. Spallanzani by the fact that he subjected his infusions to too harsh processing, as a result of which their "life force" was destroyed. (Slide number 9) According to the vitalists, the "life force" is present everywhere. It is enough just to “breathe” it, and the inanimate will become alive.
In 1862 the great French scientist Louis Pasteur (1822-1895) publishes his observations on the problem of arbitrary spontaneous generation. He proves that the sudden appearance ("spontaneous spontaneous generation") of microbes in various types of rotting tinctures or extracts is not the emergence of life. Rotting and fermentation is the result of the vital activity of microorganisms introduced from the outside. His research finally destroyed the age-old prejudices about spontaneous spontaneous generation.
Fig.1. Experience of L. Pasteur in flasks with S-shaped necks:
1 - flask with sugared yeast water; after sterilization and cooling remains sterile for a long time;
2 - the same flask 48 hours after removal of the curved neck; growth of microorganisms is observed. (slides №10,11)
- Steady State Theory (Slide number 12)
According to this theory, the Earth has existed forever, never having arisen, has always been able to support life, and any changes on it are completely insignificant. This theory does not stand up to scrutiny at the present time.
- Panspermia theory (Slide number 13)
In the 5th century BC. Greek philosopher Anaxagoras expressed the idea of cosmic seeding - panspermia(from the Greek "pan" - everything and "sperma" - seed). According to him, life arose from a seed that exists "always and everywhere." According to this theory, the germs of life are brought to Earth by meteorites or cosmic dust. This theory does not offer any mechanism for the emergence of life, simply putting forward the postulate of its extraterrestrial origin. It is argued that life could arise repeatedly at different times and in different places in the universe.
4. Modern ideas about the origin of life
(Slide 14)The modern theory of the origin of life is based on the idea that biological molecules could have originated in the distant geological past in an inorganic way.
The greatest distribution in the twentieth century. received the theory of biochemical evolution, proposed independently by the Russian chemist A.I. Oparin (1894 - 1980) and the English biologist D. Haldane (1892 - 1964).
- Theory of biochemical evolution (Slide number 15)
Stage 1 - abiogenic occurrence of organic monomers Our planet arose about 4.6 billion years ago. The gradual compaction of the planet was accompanied by the release of a huge amount of heat, radioactive compounds decayed, and a stream of hard ultraviolet radiation came from the Sun. After 500 million years, the slow cooling of the Earth began. The formation of the earth's crust was accompanied by active volcanic activity. It is believed that the primary atmosphere consisted mainly of ammonia, water, methane, carbon monoxide and carbon dioxide. The absence of oxygen gave it reducing properties. On May 3, 1924, at a meeting of the Russian Botanical Society, the young scientist A.I. Oparin expressed the opinion that in the conditions of the Earth's primary atmosphere, which differs significantly from the current one, a synthesis of all precursor substances necessary for the origin of life could take place.
Under such conditions, organic substances could be created much more easily and could be preserved without undergoing decay for a long time. A.I. Oparin believed that complex substances could be synthesized from simpler ones under ocean conditions. The energy necessary for the reactions was brought by solar radiation, since. the protective ozone screen did not yet exist; synthesis also took place under conditions of lightning discharges.
Conditions on primeval earth (slides No. 16,17):
The variety of simple compounds found in the ocean and the large time scales suggest the possibility of the accumulation of a large amount of organic matter in the ocean, which formed the "primordial soup" in which life could originate.
The scheme of formation of the “primary broth”
This theory was confirmed in the experiments of S. Miller conducted in 1953. (Slide 18)
Fig.2. Scheme of the device S. Miller:
1 - reaction flask; 2 - tungsten electrodes; 3 - spark discharge; 4 - a flask with boiling water; 5 - fridge; 6 - trap; 7 - a tap through which a gas mixture is supplied to the apparatus
Through a gas mixture containing methane, ammonia, molecular hydrogen and water vapor, i.e., simulating the atmospheric composition of the primitive Earth, he passed electrical discharges, and then analyzed the resulting reaction products. Tungsten electrodes were mounted in a reaction flask containing a mixture of gases. Spark discharges with a voltage of 60,000 V were passed during the week. In another flask (small), water was kept in a state of boiling. Water vapor passed through the reaction flask and condensed in the refrigerator. In the process of circulation, they captured the reaction products from the reaction flask and transferred them to a trap, where they were concentrated. When identifying the reaction products, organic compounds were found: urea, lactic acid and some amino acids.
Stage 2 - the formation of biological polymers and coacervates (Slide No. 19)
A.I. Oparin believed that the decisive role in the transformation of the inanimate into the living belongs to proteins. Protein molecules formed complexes with water molecules surrounding them. The merger of such complexes with each other led to their separation from the aquatic environment; coacervates(from lat. "coacervus" - clot). Drops-coacervates were able to: exchange substances with the environment, accumulate various compounds. Absorption of metal ions by coacervates led to the formation of enzymes. Proteins in coacervates protected nucleic acids from the damaging effects of ultraviolet radiation. In the drops themselves, further chemical transformations of the substances that got there took place. Lipid molecules lined up at the boundary of the droplets with the external environment, forming a primitive membrane that increased the stability of the entire system.
Stage 3 - the formation of membrane structures and primary organisms (probionts) Around the coacervates, rich in organic compounds, layers of lipids arose that separated the coacervate from the surrounding aquatic environment. Lipids were transformed in the course of evolution into the outer membrane, which significantly increased the viability and resistance of organisms. This is how probionts arose - primitive heterotrophic organisms that fed on organic substances of the primary broth. It happened 3.5 - 3.8 billion years ago. Chemical evolution is over.
The essence of the theory of A.I. Oparin can be formulated in the form of three postulates:
1. Life is one of the stages in the evolution of the Universe. 2. The emergence of life is a natural result of the chemical evolution of carbon compounds. 3. For the transition from chemical to biological evolution, the formation and natural selection of integral multimolecular systems isolated from the environment, but constantly interacting with it, which were called probionts, are necessary.
Conclusions. (Slide number 20)
Theory of life
Slides: 10 Words: 482 Sounds: 0 Effects: 85The emergence of life. Theories of origin. Theories of the origin of life. Scientific. Creationism. Evolutionism. intermediate theories. Briefly about creationism: Creationism was most widespread in Ancient Greece and Ancient Egypt. Ancient Greece. Everything originated from the eternal Chaos. Ancient Egypt. BUT still, in the religion of ancient Egypt there are many gods. Consider monotheism. Monotheism is one of the branches of creationism. Monotheistic religions include: Christianity Buddhism Islam. The concept of monotheism: Consider the example of Christianity. Initially, all creatures, including man, lived in beautiful world- paradise. - Theory of Life.ppt
The emergence of life
Slides: 8 Words: 261 Sounds: 0 Effects: 0Origin of life on earth. Hypotheses for the origin of life. Creationism. Considers the emergence of life as a manifestation of the will of God. Spontaneous generation. Panspermia hypothesis. The hypothesis of biochemical evolution. Life in the Earth. Earth as a planet, according to most scientists, has existed for 5 billion years. Influence of space on living beings. Cosmic radiation also affects the variability of weight and offspring. Experiments have shown that birds are able to navigate by the stars and by the magnetic field. Seagull in flight. - The emergence of life.ppt
Origin of life
Slides: 13 Words: 615 Sounds: 0 Effects: 52Theories of the origin of life. Experiments of Louis Pasteur. spontaneous generation of life. Refutation of the theory of spontaneous generation. L. Pasteur boiled various nutrient media in a flask. Despite the access of air, spontaneous generation was not observed. However, Pasteur conducted experiments not only to refute the theory of spontaneous generation. The work was prepared by a student of 10 "A" class. Dmitryukova Ekaterina. Creationism. The theory of creationism speaks of the origin of life as the created world of God. Theory of a steady state. The Steady State Theory states that there has always been life on Earth. The theory of panspermia. - Origin of life.ppt
Theory of life on earth
Slides: 18 Words: 1006 Sounds: 0 Effects: 0Origin of life on Earth. Theories of the origin of life on Earth: Theory of biochemical evolution. The theory of panspermia. The theory of the stationary state of life. However, the hypothesis of a stationary state fundamentally contradicts the data of modern astronomy. Theory of spontaneous generation. Ancient world. Since ancient times, mankind has solved the issues of the origin of life quite unambiguously. In Babylon, people believed that worms appeared by themselves in the channels. Antiquity. Middle Ages. Renaissance. By the 16th century, the theory of spontaneous generation of living organisms had reached its apogee. Refutation of the theory of spontaneous generation. - Theory of life on Earth.ppt
The origin of life on earth
Slides: 12 Words: 358 Sounds: 0 Effects: 0Origin of life on Earth. Theories of the origin of life on Earth. Theories of the origin of life. divine theory. Space theory. Theory of spontaneous generation. The essence of the theory. Development of life on Earth. Archean era. There are few traces of life. Proterozoic era. Organic remains are rare and scarce, but belong to all types of invertebrates. The appearance of primary chordates - a subtype of non-cranial. Palaeozoic. Ordovician, 60 Cambrian, 70 Marine invertebrates thrive. Wide distribution of trilobites, algae. Silurian, 30 Magnificent development of corals, trilobites. The appearance of jawless vertebrates - scutes. - The origin of life on Earth.ppt
Theory of the origin of life
Slides: 15 Words: 1895 Sounds: 0 Effects: 0Theories of the origin of life on Earth. Introduction. Spontaneous life. The scientist boiled various media in water in which microorganisms could form. Pasteur attached a sealed flask with a free end to the S-shaped tube. Spores of microorganisms settled on a curved tube and could not penetrate into the nutrient medium. Theory of biopoiesis. Miller and Urey's experience. It was held in 1953 by Miller and Urey. Sugars, lipids and nucleic acid precursors have also been found. The experiment was repeated several times in 1953-1954. Subsequent rains dissolved the polypeptides. - Theory of the origin of life.ppt
Origin of life theories
Slides: 12 Words: 261 Sounds: 0 Effects: 75Let's talk about theories of the origin of life. Let's consider the main theories on the example of an elementary circuit. Origin of life on earth. Biogenesis. Abiogenesis. Creationism? Spontaneous generation. Panspermia. Refutation from self-generation. Evolutionism. What is the main difference between biogenesis and abiogenesis? So… Living from living. Living from non-living. Consider panspermia. A word about creationism. biochemical evolution. Founder: A. I. Oparin (1894-1980). - Theories of the origin of life.ppt
Theories of the origin of life
Slides: 21 Words: 868 Sounds: 0 Effects: 16Public lesson. My best lesson Hypotheses for the origin of life. Stages of the emergence of the solar system. Debate. Distribution of duties. Group work in the classroom. Lesson structure. Game regulations. Judges work. Rules of judicial ethics. Lesson stage. modern hypotheses. The history of ideas about the origin of life. History of representations. origin theories. Scheme of the transition of chemical evolution. The problem of nature. Additional question. Matter. Nebula. - Theories of the origin of life.ppt
The emergence of living organisms
Slides: 21 Words: 351 Sounds: 0 Effects: 19The initial stages of the development of life. A - aromorphosis I - idioadaptation D - degeneration. Earth is an atomic gas cloud. Earth is a hot compacted body (surface temperature is more than 10,000 C). cooling of the planet. Shower rains. The emergence of reservoirs. A set of conditions. Sufficiently high surface temperature of the planet. Active volcanic activity. Lightning electrical discharges. Ultraviolet radiation. Synthesis of organic substances from inorganic compounds, proceeding in the aquatic environment. Coacervate drop = clot of organic matter. Breakup of a single drop into two or more smaller ones. - The appearance of living organisms.ppt
How life appeared on Earth
Slides: 30 Words: 1507 Sounds: 4 Effects: 28Origin of life on Earth. Topic: Development of ideas about the origin of life. To form knowledge about the main hypotheses of the origin of life on Earth. To form knowledge about the 1st and 2nd stages of biochemical evolution. Both the Earth and life are created by the Supreme Mind. Microorganisms are brought from space along with meteorites, and then evolution. Hypotheses of abiogenesis. Life arose repeatedly as a result of spontaneous generation. Hypotheses of biogenesis: The main hypotheses of the origin of life on Earth. Theories of abiogenesis lasted for many centuries. Hypotheses of abiogenesis: spontaneous generation. What will happen? - How life appeared on Earth.ppt
Origin of life on earth
Slides: 42 Words: 1748 Sounds: 0 Effects: 189Origin of life on Earth. Lesson goals. Lesson plan. 1. History of ideas about the origin of life on Earth. The idea of the origin of life on Earth by scientists - philosophers of antiquity and the Middle Ages. Theories of biogenesis and abiogenesis. The hypothesis of spontaneous generation of life. 2. Analysis of the definition of life by F. Engels and modern scientists. Definition of life according to F. Engels. life criteria. Definition of life according to modern concepts. The place of the biological form of the movement of matter among other forms. 3. Prerequisites for the emergence of life on Earth. Evolution of chemical elements in outer space. - Origin of life on Earth.ppt
Origin of life on earth
Slides: 15 Words: 531 Sounds: 0 Effects: 43Integrated lesson. Origin of life on earth. So how did life appear on our planet? Michelangelo Buanarotti: The Creation of Adam. The hypothesis of spontaneous origin of life. Ancient engravings: on the left - the transformation of fruits into fish and birds; on the right - in ducks. Steady State Hypothesis. Earth and life have always existed, forever. Species have always existed, but they could die out or change their numbers. Panspermia hypothesis ("seeds everywhere"). Hypothesis of biochemical evolution. Stages of the origin of life on the planet (according to Oparin): Geophysical stage. "Big Bang". - The origin of life on Earth.ppt
Origin of life hypotheses
Slides: 45 Words: 1386 Sounds: 0 Effects: 56Lesson topic: Development of ideas about the origin of life on Earth. Hypotheses about the origin of life on Earth. How did life originate on Earth? What are the views and hypotheses about the origin of life on Earth? What is life? Friedrich Engels (November 28, 1820 - August 5, 1895, London) - German philosopher, one of the founders of Marxism, friend, associate and co-author of Karl Marx. Mikhail Vladimirovich Volkenshtein (October 10 (23), 1912, St. Petersburg - February 18, 1992, Moscow) - Soviet physical chemist and biophysicist, corresponding member of the Russian Academy of Sciences. Valenti?n Nikolaevich Parm?n (born April 18, 1948, Brandenburg) is a Russian scientist. - Hypotheses of the origin of life.ppt
Hypotheses of the origin of life
Slides: 10 Words: 295 Sounds: 0 Effects: 3The origin of man. Hypotheses. Hypotheses of the origin of life: Creationism. Divine creation of the world. Spontaneous generation. Pansmermia hypothesis. Stationary state. Theory of oparin-holdin. The hypothesis of biochemical evolution, or "coacervate hypothesis". A.I. Oparin gave primacy in the formation of life to proteins, and J. Haldane to nucleic acids. - Hypotheses of the origin of life.pptx
The emergence and development of life
Slides: 11 Words: 159 Sounds: 0 Effects: 47The emergence and initial development of life on Earth. F a l e s. Water is everything… A n a k s i m a n d r. The beginning of all things is "apeiron". Heraclitus. The basis of everything is fire ... Democritus. The beginnings of the Universe are atoms and emptiness. Aristotle. The world consists of five elements: earth, water, air, fire, and ether. Assembly of coacervates. Coacervate drops obtained in the experiment. S External environment. A Substance enters the drop. B Reaction product. Z External environment. Diagram of an open system. Conclusions. Life originated on Earth in an abiogenic way. Biological evolution was preceded by a long chemical evolution. - The emergence and development of life.ppt
Theories of the origin of life on Earth
Slides: 26 Words: 3535 Sounds: 0 Effects: 0Origin of life on earth. Life fills all corners of our planet. For billions of years, life has been walking the Earth as a unique self-organizing system. Today science knows about 4.5 million species of animals and plants. Since time immemorial, the origin of life has been a mystery to mankind. Prerequisites for the emergence of life on Earth. Such gas-dust matter is found in interstellar space at the present time. Hydrogen is the predominant element in the universe. One of these conditions is the size of the planet. An example of such planets is the Earth's satellite - the Moon. - Theories of the origin of life on Earth.pptx
Problems of the origin of life on Earth
Slides: 16 Words: 1540 Sounds: 1 Effects: 229Origin of life on Earth. History of ideas about the origin of life. Conditions for the emergence of primitive living beings. Representations of ancient and medieval philosophers. Works by L. Pasteur. Theories of the origin of life. The history of carbon. From carbon to proteins. Possibility of formation of complex organic compounds. Age of the Earth. The emergence of primary organisms. coacervate droplets. Development of life. The emergence of multicellular organisms. - Problems of the origin of life on Earth.ppt
Development of ideas about life on Earth
Slides: 37 Words: 1175 Sounds: 0 Effects: 77Development of ideas about the origin of life on Earth. Heads in caps. A life. The mode of existence of protein bodies. properties of the living. Hypothesis. Problem questions. Democritus. Jan Van Helmont. Francesco Redi. Gottfried Leibniz. Anthony van Leeuwenhoek. Lazzaro Spallanzani. Louis Pasteur. Forms. Soviet biochemist. Theory of biochemical evolution. Experiences. Charles Darwin. The process of existence of complex systems. Divine creation of the world. German scientist. Stages of the process of the origin of life. English biologist. Oparin's hypothesis. The living comes only from the living. Life in the Earth. - Development of ideas about life on Earth.ppt
Panspermia theory
Slides: 8 Words: 397 Sounds: 0 Effects: 13The theory of panspermia - life on our planet is brought from outside, from the Universe. The hypothesis was put forward in the middle of the XIX century. Hypothesis. With the help of panspermia, the emergence of life on Earth was also explained. Evidence. Technogenic panspermia. Modern evidence for panspermia. Fred Hoyle's suggestion. As a result, the universe remains on average unchanged. - Panspermia theory.ppt
The Big Bang Theory
Slides: 11 Words: 291 Sounds: 0 Effects: 6Origin of life on earth. The Big Bang Theory. Creationism spontaneous generation steady state theory panspermia theory biochemical evolution. Theories of the origin of life on earth. Molecules of organic substances combined with each other, forming chains of nucleic acids. Apparently, such complexes were the prototype of future cells. biochemical evolution. The Big Bang theory was proposed by scientists Friedman and Lemaitre. The space quickly expanded, t flying particles with high energy began to decline. The Big Bang period is conventionally called the time interval from zero to several hundred seconds. -
The origin of life on Earth The history of ideas about the origin of life. Modern ideas about the origin of life. Theories of the origin of protobiopolymers. Evolution of protobionts. The initial stages of biological evolution. The origin of life on Earth The history of ideas about the origin of life Theories of the origin of protobiopolymers. Evolution of protobionts. Representations of philosophers Modern ideas about the origin of life Initial stages of biological evolution. Formation of planetary systems Works of L. Pasteur Primary atmosphere of the Earth Theories of eternity of life Sources of energy and age of the Earth Theories of the origin of life Environmental conditions on the ancient Earth It is often argued that at present there are all the conditions for the emergence of primitive living beings that were once. But if now in any reservoir containing all the necessary ammonium salts and phosphates and accessible to light, heat, electricity, etc., a protein capable of further more and more complex transformations was chemically formed, then this protein would immediately be destroyed or absorbed, which was not possible in the period before the creation of living beings. Charles Darwin Representations of Ancient and Medieval Philosophers. General level of knowledge in ancient world was low, and the ideas prevailing at that time were distinguished by their fantastic character. So, Empedocles (5th century BC) attributed to trees the ability to carry eggs. It is not surprising, therefore, that even such a prominent scientist as Aristotle (4th century BC) expressed similar views, absurd from our point of view. For example, Aristotle Works of L. Pasteur. The works of L. Pasteur were a turning point in the history of the doctrine of the origin of life. The question of spontaneous generation was resolved, and the principle "everything is from life" for all known creatures could be considered fair and not knowing not one exception. Along with this, old ideas about the origin and eternity of the theory of the origin of life reappeared. All religions, and in particular the Christian one, teach that plants, animals and people at the “creation of the world” were created by God about the same as they are now. Therefore, according to religious ideas, our planet was from the very beginning inhabited by the same species of living beings. The statement of the church was refuted by the great English scientist Charles Darwin. He was able to scientifically prove that all highly organized beings of our time descended from organisms that were more simply arranged, through evolution, that is, through sequential development. The study of fossil remains preserved in the earth's crust from living creatures that once inhabited our planet fully confirmed Darwin's teachings. The earth has not always been inhabited by the same species of living beings. Living beings arose as a result of the consistent development of relatively simple living organisms. The older the fossil remains of organisms, the simpler the structure of these organisms. How then did the primary organisms - the ancestors of all life on Earth - arise? Before such a question, Darwin himself stopped in thought. At the end of the last century, F. Engels suggested that such primitive living beings could arise only as a result of the development of lifeless matter. At the end of the last century, F. Engels suggested that such primitive living beings could arise only as a result of the development of lifeless matter. However, at that time, scientists could not yet imagine the successive steps in the development of inanimate matter into living organisms. This was possible only in the 20th century, when a sufficient amount of scientific information was accumulated. The history of carbon. The history of the formation of the Earth shows that during the formation of our planet and in the first periods of its existence, enormous quantities of the simplest organic substances arose on the surface of the globe. It is now generally accepted in astronomy that the Earth and other planets solar system formed from a giant cloud of gas and dust matter. Such gas and dust matter exists in interstellar space even now. Astronomers have learned to determine its composition. It contains methane (CH4). Perhaps there are more complex hydrocarbons. When the particles of the gas and dust cloud united into large planets (Jupiter, Saturn), methane and other gases remained in the primary atmosphere of the formed planets. Astronomers are still detecting these gases there. And in the composition of the Earth - it is, after all, a relatively small planet - carbon remained only in the form of graphite and carbides (compounds of carbon with metals). From carbides, when they interact with water, hydrocarbons are formed, and water was also part of the Earth - in the form of hydrates of various rocks. Consequently, hydrocarbons and their simplest derivatives must inevitably have formed on Earth long before the appearance of living beings on it. From carbon to proteins. The age of the earth is determined by science different ways within 5 billion years, life has existed on it for more than 2 billion years. Thus, for the greatest period of its existence, our planet was lifeless. And hydrocarbons and the simplest organic substances that arose from them began to appear on the earth's surface from the very beginning of its formation. They served as the initial link in that long chain of transformations that eventually led to the emergence on the earth's surface, in its water shell and in the atmosphere of a large number of diverse and sometimes very complex substances. The very nature of hydrocarbons already contains the possibility of such transformations. But in order for them to occur, a sufficient influx of energy from the outside is needed. Such energy on the earth's surface was available in several forms: the radiant energy of the Sun, in particular ultraviolet light. The possibility of the formation of complex organic compounds under the conditions that were on the surface of the Earth in the initial periods of its existence can be proved even by direct laboratory experiments. Recently, the American researcher S. Miller artificially reproduced the conditions of the Earth's primary atmosphere: he passed quiet electric discharges through a mixture of methane, hydrogen, ammonia, and water vapor. The result is amino acids - the main components of the protein molecule. The Indian scientist K. Bahadur in a similar experiment obtained amino acids by exposure to sunlight. This experience, by using ultraviolet rays, was significantly refined by our scientists at the Institute of Biochemistry. A. N. Bach of the Academy of Sciences of the USSR. The experiments of the Japanese scientist Sh. Akabori also showed how, under the conditions of the primary periods of the Earth's existence, protein-like substances could form from the combination of amino acids, more precisely, from their immediate predecessors. Age of the Earth The age of the Earth is determined by science in various ways within 5 billion years, life has existed on it for more than 2 billion years. Thus, for the greatest period of its existence, our planet was lifeless. And hydrocarbons and the simplest organic substances that arose from them began to appear on the earth's surface from the very beginning of its formation. They served as the initial link in that long chain of transformations that eventually led to the emergence on the earth's surface, in its water shell and in the atmosphere of a large number of diverse and sometimes very complex substances. The very nature of hydrocarbons already contains the possibility of such transformations. But in order for them to occur, a sufficient influx of energy from the outside is needed. Such energy on the earth's surface was available in several forms: the radiant energy of the Sun, in particular ultraviolet light, electrical discharges in the atmosphere, the energy of atomic decay of natural radioactive substances. The emergence of primary organisms When such protein-like substances arose on Earth, new stage in the development of matter - the transition from organic compounds to living beings. At first, organic substances were in the seas and oceans in the form of solutions. They didn't have any building, any structure. But when solutions of proteins or other similar organic compounds are mixed with each other, special semi-liquid ones are released from the solutions. Although coacervate droplets are liquid, they have a certain internal structure. Particles of matter in them are not arranged randomly, as in a solution, but with a certain regularity. With the formation of coacervates, the rudiments of organization appear, however, still very primitive and unstable. For the most droplet, this organization has great importance. Any coacervate droplet is capable of trapping certain substances from the solution in which it floats. They chemically attach themselves to the substances of the droplet itself. Thus, the process of creation, growth takes place in it. But in any drop, along with creation, decay is also observed. One or another of these processes, depending on FURTHER DEVELOPMENT OF LIFE. The structure of these primary living organisms was much more perfect than that of coacervate droplets. But still, it was incomparably simpler than even the simplest living beings today. Natural selection, which began in coacervate droplets, continued with the advent of life. Centuries, millennia passed, and the structure of living beings improved more and more, adapted to the conditions of existence. At the dawn of life, both plants and animals were the smallest single-celled creatures, similar to bacteria living in our time, blue-green algae, amoeba. A great event in the history of the consistent development of living nature was the emergence of multicellular organisms, that is, living beings consisting of many cells combined into one organism. Gradually, but much faster than before, living organisms became more complex and diverse. The end … Worked on the presentation: Student 10 3rd grade of gymnasium No. 13 Ibragimova Khazina
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