If you walk along the beach and find an interesting fossil stone, you immediately understand that it may belong to a long-extinct species. The idea that species are dying out is so familiar to us that it's hard to even imagine a time when people thought that every single type of creature still lives anywhere. People believed that God created everything - why would he create something that could not survive?
George Cuvier was the first person to ask this question. In 1796 he wrote an article on elephants in which he described African and Asian varieties. He also mentioned a third type of elephant known to science only from its bones. Cuvier noted key differences in the third elephant's jaw shape and suggested that the species must be entirely separate. The scientist called it a mastodon, but then where are the living individuals?
According to Cuvier, "all these facts are consistent with each other and do not contradict any other message, so it seems to me possible to prove the existence of a world that preceded ours and was destroyed due to a kind of catastrophe." He did not stop at this revolutionary idea alone. Cuvier studied the fossils of other ancient animals - coining the term "pterodactyl" along the way - and found that reptiles were once the dominant species.
First cells grown outside the body
If a biologist wants to study the inner workings of animal cells, it is much easier if those cells are not part of the animal at the time. Currently, biologists are cultivating wide strips of cells in a test tube, which greatly simplifies the task. The first person to try to keep cells alive outside the host body was Wilhelm Roux, a German zoologist. In 1885, he placed part of a chicken embryo in saline and kept it alive for several days.
For several decades, research continued using this particular method, but in 1907 someone suddenly decided to grow new cells in solution. Ross Harrison took tissues from a frog embryo and was able to grow new nerve fibers from them, which he then kept alive for a month. Today, cell samples can be kept alive almost indefinitely - scientists are still experimenting with cell tissues from a woman who died 50 years ago.
Discovery of homeostasis
You have probably heard something about homeostasis, but in general it is very easy to forget how important it is. Homeostasis is one of the four important principles modern biology, along with evolution, genetics and cell theory. The main idea is in a short phrase: Organisms regulate their internal environment. But as in the case of others important concepts, which can be fit into a short and capacious phrase - objects with mass are attracted to each other, revolve around the Sun, there is no catch - this is a really important understanding of the nature of our world.
The idea of homeostasis was first put forward by Claude Bernard, a prolific mid-19th century scientist who was kept awake by the fame of Louis Pasteur (although they were friends). Bernard made serious progress in understanding physiology, despite the fact that his love of vivisection destroyed his first marriage - his wife rebelled. But the true importance of homeostasis - which he called milleu interieur - was recognized decades after Bernard's death.
In an 1887 lecture, Bernard explained his theory thus: “The living body, although it needs an environment, is relatively independent of it. This independence from the external environment stems from the fact that in a living being, the tissues are essentially separated from direct external influences and protected by a true internal environment, which consists, in particular, of the fluids circulating in the body.
Scholars who are ahead of their time often go unrecognized, but Bernard's other work was enough to bolster his reputation. Nevertheless, it took nearly 50 years for science to test, validate, and evaluate his most important idea. An entry about it in the Encyclopedia Britannica for 1911 says nothing at all about homeostasis. Six years later, the same article on Bernard calls homeostasis " major achievement epoch."
First isolation of the enzyme
Enzymes are usually first learned in school, but if you've been skipping classes, let's explain: they are large proteins that help the flow chemical reactions. In addition, they make an effective washing powder based on them. They also provide tens of thousands of chemical reactions in living organisms. Enzymes (enzymes) are just as important to life as DNA - our genetic material cannot replicate itself without them.
The first enzyme discovered was amylase, also called diastase, and it's in your mouth right now. It breaks down starch into sugar and was discovered by the French industrial chemist Anselme Payen in 1833. He isolated the enzyme, but the mixture was not very pure. For a long time, biologists believed that extracting a pure enzyme might be impossible.
It took almost 100 years for the American chemist James Batchler Sumner to prove them wrong. In the early 1920s, Sumner began isolating the enzyme. His goals were so audacious that they actually cost him the friendship of many of the leading experts in the field, who thought his plan would fail. Sumner continued and in 1926 isolated urease, an enzyme that breaks down urea into its chemical components. Some of his colleagues doubted the results for years, but in the end they, too, had to give up. Sumner's work brought him Nobel Prize in 1946.
The assumption that all life has a common ancestor
Who was the first to suggest that all life evolved from a single creature? You say: . Yes, Darwin developed this idea - in his "Origin of Species" he wrote the following: "There is a certain greatness in such a view of such a life, with its various manifestations, which was originally embodied in several forms or in one." However, while we are in no way minimizing Darwin's accomplishments, the idea of a common ancestor was put forward decades earlier.
In 1740, the famous Frenchman Pierre Louis Moreau de Maupertuis suggested that "blind fate" produced a wide range of individuals, of whom only the most able survived. In the 1790s, Immanuel Kant noted that this could refer to the original ancestor of life. Five years later, Erasmus Darwin wrote: "Would it be too bold to assume that all warm-blooded animals are descended from a single living thread?". His grandson Charles decided that there was no "too much" and guessed.
Invention of cell staining
If you have ever seen microscopic photographs of cells (or looked at them yourself), there are many high chance that they were first painted. Coloring allows us to see those parts of the cell that are usually not visible, and generally increase the clarity of the picture. There are a lot of different methods for staining cells, and this is one of the most fundamental techniques in microbiology.
The first person to color a specimen for examination under a microscope was Jan Swammerdam, a Dutch naturalist. Swammerdam is best known for his discovery of red blood cells, but he also made a career out of looking at everything under a microscope. In the 1680s, he wrote about the "colored liquor" of dissected worms, which "make it possible to better identify the internal parts, because they are of the same color."
To Swammerdam's regret, this text was not published for at least another 50 years, and by the time of publication Jan was already dead. At the same time, his fellow countryman and naturalist Anthony van Leeuwenhoek, independently of Swammerdam, came up with the same idea. In 1719 Leeuwenhoek used saffron to stain muscle fibers for further examination and is considered the father of this technique. Since both men came up with this idea independently and still made their reputation as pioneers of microscopy, they must have worked out quite well for them.
Development of cell theory
“Every living being is made up of cells” - this phrase is as familiar to us as “The Earth is not flat”. Today, cell theory is taken for granted, but in fact it was beyond our knowledge until the 19th century, 150 years after Robert Hooke first saw cells through a microscope. In 1824, Henri Duroche wrote of the cell: “It is evident that it is the basic unit of an ordered state; indeed, everything ultimately comes from the cell.”
In addition to being the basic unit of life, the cell theory also implies that new cells are formed when another cell divides into two. Duroce skipped this part (in his opinion, new cells form inside their parent). The final understanding that cells divide to reproduce is due to another Frenchman, Barthelemy Dumortier, but there were other people who made a significant contribution to the development of ideas about cells (Darwin, Galileo, Newton, Einstein). The cell theory was created in small mites, about the same as today modern science.
DNA sequencing
Until his recent death, British scientist Frederick Sanger was the only living person to win two Nobel Prizes. It was the work for the second prize that led to the fact that he got on our list. In 1980 he received the top science prize along with Walter Gilbert, an American biochemist. In 1977, they published a method to figure out the sequence of the building blocks in a DNA strand.
The significance of this breakthrough is reflected in how quickly the Nobel Committee rewarded scientists. Eventually Sanger's method became cheaper and simpler, becoming the standard for a quarter of a century. Sanger paved the way for revolutions in the fields of criminal justice, evolutionary biology, medicine, and more.
Discovery of viruses
In the 1860s, Louis Pasteur became famous for his germ theory of disease. But Pasteur's microbes were only half the story. Early proponents of the germ theory thought that all infectious diseases were caused by bacteria. But it turned out that colds, flu, HIV and other endless health problems are caused by something completely different - viruses.
Martinus Beijerinck was the first to realize that not only bacteria are to blame for everything. In 1898, he took juice from tobacco plants suffering from the so-called mosaic disease. Then I filtered the juice through a sieve so fine that it should have filtered out all the bacteria. When Beijerinck anointed healthy plants with juice, they got sick anyway. He repeated the experiment - and still got sick. Beijerink concluded that there was something else, perhaps a liquid, that was causing the problem. He called the infection vivum fluidum, or soluble living bacteria.
Beijerink also picked up the old English word"virus" and endowed them with a mysterious agent. The discovery that viruses were not liquid belongs to the American Wendell Stanley. He was born six years after the discovery of Beijerinck and, apparently, immediately understood what needed to be done. Stanley shared the 1946 Nobel Prize in Chemistry for his work on viruses. Remember who you shared with? Yes, with James Sumner for work on enzymes.
Rejection of preformism
One of the most unusual ideas in history was preformism, once the leading theory about the creation of the baby. As the name implies, the theory suggested that all creatures were pre-created - that is, their form was already ready before they began to grow. Simply put, people believed that a miniature human body was inside every sperm or egg looking for a place to grow. This tiny little man was called a homunculus.
One of the key proponents of preformism was Jan Swammerdam, the inventor of the cell-staining technique discussed above. The idea was popular for hundreds of years, from the middle of the 17th century until the end of the 18th.
An alternative to preformism was epigenesis, the idea that life arises in a series of processes. The first person to put forward this theory against the backdrop of a love of preformationism was Caspar Friedrich Wolff. In 1759, he wrote an article in which he described the development of an embryo from several layers of cells to a person. His work was highly controversial at the time, but the development of microscopes put everything in its place. Embryonic preformism died far from being in the bud, but it died, pardon the pun.
Based on materialslistverse.com
The study of any living object in one way or another concerns its biological properties and interaction with the outside world.
We can say that a person began to study biology as soon as he became rational:
- Zoology, botany, ecology. Animal study and flora in the early stages of development human society as a source of food, habitat and distribution of animals and plants.
- Genetics and selection. Domestication of animals and breeding of new breeds, cultivation of plants and obtaining new varieties with desired properties.
- Medicine, veterinary medicine, biotechnology and bioinformatics. The study of the functioning of living organisms in order to improve physiological performance. Development of the pharmaceutical industry and the food industry.
Biology in the modern world
Like any science, over time, biology has acquired more advanced ways of studying the world around us, but has not lost its significance both for each individual and for society as a whole.
Examples
Some achievements of biological science have remained virtually unchanged since their introduction into human life, some have undergone serious modifications and reached the industrial level, and some became possible only in the 20th century thanks to scientific and technological progress.
- Yeast and lactic acid is the production of bread, beverages, dairy products and food additives and feed additives for animals.
- Molds and genetically modified bacteria: drugs, citric acid.
- Oil-degrading bacteria help fight oil pollution.
- The simplest decompose organic waste in sewage treatment plants.
- Hydroponics - growing plants without soil helps to develop agro-industrial complex in areas where, due to climate Agriculture difficult.
- The cultivation of cell and tissue cultures "in vitro" looks very promising. food industry will receive only the edible plant parts without the need for additional processing. For medicine, huge opportunities are opening up for organ and tissue transplantation without searching for a donor.
"The study of biology" - Genetic mechanism. Topical issues in biology. Thank you for your attention! Methods of genomics. DNA sequencing. Electrophoresis. Cellular engineering. Increase in oxidation processes. Why are we dying? Thanatology is the science of death. Creative title: Do you want to know more? Topic: New directions in biology.
When discussing the experience of female students in the discipline, it is important to recognize that students are not monoliths. Gender is a complex identity based on a person's inner experience of who he or she is. Thus, people can differ in the extent to which they identify with their gender, the gender roles associated with their gender, and in how their gender identity influences their experiences in different settings such as the classroom. In addition, gender is only one of many social identities that make up who we are and how we respond to certain conditions.
"Biology game" - Additions to the game. The name of which disease comes from the Latin verb "to choke"? Not only a unit of speed of sea vessels, but also a section of the stem. What living creatures did K. Linnaeus classify as "chaos"? Write a famous proverb. What breed was the dog in D. London's story "White Fang"? 80. "Shaggy bumblebee for fragrant hops ..." Music by A. Petrov, but whose words?
Just as all women are not the same, not all biology classes are the same. One classroom factor that has been found to have some influence on achievement and participation is teacher gender. Some studies have found that same-sex teachers, especially student instructors, perceived as competent can improve the performance of female students, while other studies have found no difference.
The first course in the series focuses on evolution and ecology; second in molecular, cellular and developmental biology; and third in plant and animal physiology. Students taking the Introductory Biology Series are predominantly sophomores and biology majors. Although this is a series of three courses, not all specialty scholars are required to take all three. Individual lessons ranged from 159 to over 900 students, depending on the term. Teaching methods varied between instructors; some were taught exclusively through passive learning methods, while others were highly organized and interactive.
"Portfolio educational achievements» - Portfolio Philosophy. Possibility of both qualitative and quantitative evaluation of portfolio materials. Student's personal diary. What is a portfolio? How did it all start? Concept. Student's resume. Analysis of the survey of students of the State Medical University No. 2. Khudyakova T.M. Student portfolio. Section "summary summary sheet".
In addition, the exam format varied from almost exclusively essay to exclusively multiple choice, with most classes using short answer formats. Although some classes were taught by one instructor, most classes were assigned by two instructors, each teaching for 5 weeks. A total of 26 teachers taught these 23 classes. Gender gender also varied across these classes, with 3% taught exclusively by one or two male instructors, 5% had both male and female instructors, and 2% had either one or two female instructors.
"Achievements of Astronomy" - Disagreement with previous observations. 1821 tables published. Independently studied astronomy. Search for annual parallax Friedrich Bessel (1784-1846). State of the art tools. Publication. Deviation of the orbit of Mercury Perihelion longitude - 527 in 100 years. Search for the annual parallax Vasily Yakovlevich (Wilhelm) Struve (1793-1864).
Demographic information collected by the University Registrar showed that on average 1% of students in these grades identified as female, but this number varied from 53% to 64% depending on the specific grade. Another 6% were international students.
Study 1: Is there a gap in achieving gender equality in introductory biology?
We also recorded gender differences in the gender identity of instructors: 0=no female instructors, 1=half of the class taught by a female instructor, 2=full class taught by a female instructor. The response variable for our analysis was overall performance on class exams.
"Achievements of the XIX century" - The first railway ran between St. Petersburg and Moscow on November 1, 1851. Conclusion: urban transport has changed, transportation of people has become better. The streets were lit first with kerosene and then with gas lamps. Conclusion: it became easier for people to communicate with each other. Fashion changed: dresses became more refined, more sophisticated, and also more comfortable to use.
Students differ in many ways that can affect exam performance. We assumed that exam scores would be influenced by gender and ethnicity, and so they included these terms in our analyses. In addition, including a covariate that captures some aspects of academic achievement in our models allows us to more accurately test the effect of our variables of interest on our outcome variable.
Multilevel models differ in many ways from traditional linear regression models. The first layered models are the mixed effects model, which includes fixed and random effects. Fixed effects are usually the variables of interest, and linear regressions assume that all variables are fixed. In mixed effects models, some variables may be random. Random effects are random effects that can be seen to be drawn randomly from a population.
"USE in biology 2009" - The analysis was compiled on the basis of the report of the chairman of the examining committee of the exam in biology Voronin L.V. The average score in Russia is 52.3 in the Yaroslavl region 54.3 in the city of Yaroslavl 54.0. The most difficult tasks of part C. General shortcomings in the answers of part C. The results of the exam in biology 2009. 100 points were scored by 2 people in the Yaroslavl region, including Tatyana Berseneva from gymnasium No. 3 in Yaroslavl Average score more than 70 - schools No. 80 and No. 33.
For example, students participating in a particular class may be considered a random effect if a subset of the classes used in a study can be considered as being chosen at random from a larger pool of possible classes. These preliminary results indicate that the size of the gender gap is not unique to any particular combination of course structure, exam format, or instructor.
In this study, the only class factor we were able to isolate was the instructor's gender identity. To determine which fixed effect variables best explain patterns in student exam scores, we used a powerful multimodal inference technique using the Akaika information criterion. This statistical technique is commonly used in the fields of ecology, evolution, and behavior when the data come from observational studies with a large number of possible explanatory variables.
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Achievements in biology modern versions systematics of life
Only students with a full set of these variables were included in this analysis. The combinations of these variables yielded a total of 26 potential models to describe our data. The total number of models tested was well below our number of observations, justifying a full study of this set of models. Thus, we systematically explored the possible models of our data and eventually chose the model that best fits the data according to the model selection statistics.
Study Findings 1: Is there a Gender Success Gap in Introductory Biology?
We also computed the regression coefficient-averaged coefficients for the fixed effects in our model. Our original complete model was as follows. Most of the two models had great support. The best model included three of the six possible fixed effects. The second best model included two instructor variables.
Living nature arranged itself brilliantly simply and wisely. It has the only self-reproducing DNA molecule on which the life program is written, and more specifically, the entire synthesis process, the structure and function of proteins as the basic elements of life. In addition to preserving the life program, the DNA molecule performs another important function - its self-reproduction, copying create continuity between generations, the continuity of the thread of life. Once having arisen, life reproduces itself in a huge variety, which ensures its stability, adaptability to various environmental conditions and evolution.
The student identity variable was a relative importance variable of 1 and was present in all six top models, implying that gender had a consistent and robust impact. In our analyses, the main effect of the race at the examination points was confirmed. It is also only present in the fifth most well supported model and this model does not have much support compared to the best model.
Using model average coefficients that include this uncertainty about the relationship between teacher gender identity and student achievement, we find that only the interaction between student gender identity and women exclusively teaches this class, which has a significant positive impact on student exam performance. This would mean that the gender gap in a class with two female instructors would be reduced from 11 points to 7 points.
Modern biotechnologies
Modern biology is an area of rapid and fantastic transformations in biotechnology.
Biotechnologies are based on the use of living organisms and biological processes in industrial production. On their basis, mass production of artificial proteins, nutrients and many other substances, superior to products of natural origin in many properties, has been mastered. The microbiological synthesis of enzymes, vitamins, amino acids, antibiotics, etc. is successfully developing. With the use of gene technologies and natural bioorganic materials, biologically active substances are synthesized - hormonal preparations and compounds that stimulate the immune system.
Study 2: Are there gender gaps in participation in student-teacher interactions across the class. Over a 2-year period, 26 instructors taught the introductory biology series. Although many instructors taught courses more than once during this 2-year period, participation data was collected from only one quarter for each of the 26 instructors. We observed individual classroom sessions to determine participation rates. found that two trained person, each observing one 45-minute session of the teacher's class, have a confidence score of 67, and this paired observation of one session is as reliable as independent observations of four sessions. To be conservative and increase the number of selected student teachers, we randomly selected three class sessions for each instructor.
Modern biotechnology makes it possible to turn waste wood, straw and other plant materials into valuable nutritious proteins. It includes the process of hydrolysis of the intermediate product - cellulose - and the neutralization of the resulting glucose with the introduction of salts. The resulting glucose solution is a nutrient substrate for microorganisms - yeast fungi. As a result of the vital activity of microorganisms, a light brown powder is formed - a high-quality food product containing about 50% of raw protein and various vitamins. Sugar-containing solutions such as treacle stillage and sulfite liquor from pulp production can also serve as a nutrient medium for yeasts.
In this study, we focused solely on student verbal interactions that occurred in the context of the entire class. Although there are other ways for students to interact in the classroom, we were unable to analyze these conversations using all the video recordings of the entire class.
The event was coded as a spontaneous student question when a student asked an instructor an unguided question or was only triggered in general: "Does anyone have a question?" Volunteer responses were characterized by students raising their hands or shouting answers of their own free will in response to the instructor's questions. These volunteer responses included only those students who chose to participate. The random call has a specific structure similar to a cold call, with the instructor calling students by name to answer questions that are heard by the entire class.
Some types of fungi convert oil, fuel oil and natural gas into protein-rich edible biomass. Thus, 10 tons of yeast biomass containing 5 tons of pure protein and 90 tons of diesel fuel can be obtained from 100 tons of crude fuel oil. The same amount of yeast is produced from 50 tons of dry wood or 30 thousand m3 of natural gas. To produce this amount of protein would require a herd of 10,000 cows, and to maintain them, huge areas of arable land are needed. The industrial production of proteins is fully automated, and yeast cultures grow thousands of times faster than cattle. One ton of nutritional yeast allows you to get about 800 kg of pork, 1.5-2.5 tons of poultry or 15-30 thousand eggs and save up to 5 tons of grain.
However, random calling differs from cold calling in that the instructor does not decide who he or she will call. Instead, the instructor comes to the class with a randomized list of classes and calls out the names of the students in the order in which the names appear on the list. The observers were able to distinguish the random call from the responses of the volunteers in the video by observing the behavior of the instructor. When called randomly, the instructor calls out the students' first and last names without waiting for volunteers, and they can often be seen referring to the list before saying the student's name.
The practical application of the achievements of modern biology already at the present time makes it possible to obtain industrially significant amounts of biologically active substances.
Biotechnology, apparently, will take a leading position in the coming decades and, perhaps, will determine the face of civilization in the 21st century.
Gene technologies
Genetics is the most important area of modern biology.
On the basis of genetic engineering, modern biotechnology was born. There are now a huge number of firms doing business in this area in the world. They do everything from drugs, antibodies, hormones, food proteins to technical things - ultra-sensitive sensors (biosensors), computer microcircuits, chitin cones for good acoustic systems. Genetically engineered products are conquering the world, they are environmentally safe.
At the initial stage of the development of gene technologies, a number of biologically active compounds were obtained - insulin, interferon, etc. Modern gene technologies combine the chemistry of nucleic acids and proteins, microbiology, genetics, biochemistry and open up new ways to solve many problems in biotechnology, medicine and agriculture.
Gene technologies are based on the methods of molecular biology and genetics associated with the purposeful construction of new combinations of genes that do not exist in nature. The main operation of gene technology is to extract from the cells of an organism a gene encoding the desired product, or a group of genes, and combine them with DNA molecules that can multiply in the cells of another organism.
The DNA stored and working in the cell nucleus reproduces more than just itself. At the right moment, certain sections of DNA - genes - reproduce their copies in the form of a chemically similar polymer - RNA, ribonucleic acid, which in turn serve as templates for the production of many proteins necessary for the body. It is proteins that determine all the signs of living organisms. The main chain of events at the molecular level:
DNA -> RNA -> protein
This line contains the so-called central dogma of molecular biology.
Gene technologies have led to the development of modern methods for the analysis of genes and genomes, and they, in turn, to synthesis, i.e. to the construction of new, genetically modified microorganisms. To date, the nucleotide sequences of various microorganisms, including industrial strains, have been established, and those that are needed to study the principles of genome organization and to understand the mechanisms of microbial evolution. Industrial microbiologists, in turn, are convinced that knowledge of the nucleotide sequences of the genomes of industrial strains will allow them to be "programmed" so that they bring in a lot of income.
Cloning of eukaryotic (nuclear) genes in microbes is the fundamental method that led to the rapid development of microbiology. Fragments of the genomes of animals and plants are cloned in microorganisms for their analysis. To do this, artificially created plasmids are used as molecular vectors, gene carriers, as well as many other molecular entities for isolation and cloning.
With the help of molecular samples (DNA fragments with a certain sequence of nucleotides) it is possible to determine, say, whether donated blood is infected with the AIDS virus. And genetic technologies for identifying some microbes make it possible to monitor their spread, for example, inside a hospital or during epidemics.
Gene technologies for the production of vaccines are developing in two main directions. The first is the improvement of already existing vaccines and the creation of a combined vaccine, i.e. consisting of several vaccines. The second direction is obtaining vaccines against diseases: AIDS, malaria, stomach ulcers, etc.
In recent years, gene technologies have significantly improved the efficiency of traditional producer strains. For example, in a fungal strain producing the antibiotic cephalosporin, the number of genes encoding expandase, the activity that determines the rate of cephalosporin synthesis, has been increased. As a result, antibiotic production increased by 15-40%.
Purposeful work is being carried out to genetically modify the properties of microbes used in the production of bread, cheese making, the dairy industry, brewing and winemaking in order to increase the resistance of production strains, increase their competitiveness in relation to harmful bacteria and improve the quality of the final product.
Genetically modified microbes are beneficial in the fight against harmful viruses and germs and insects. For example:
Plant resistance to herbicides, which is important for controlling weeds that clog fields and reduce the yield of cultivated plants. Herbicide-resistant varieties of cotton, corn, rapeseed, soybean, sugar beet, wheat and other plants have been obtained and are being used.
Plant resistance to insect pests. Development of the delta-endotoxin protein produced by different strains of the bacterium Bacillus turingensis. This protein is toxic to many insect species and is safe for mammals, including humans.
Plant resistance to viral diseases. To do this, genes that block the reproduction of viral particles in plants, such as interferon, nucleases, are introduced into the plant cell genome. Transgenic plants of tobacco, tomatoes and alfalfa with the beta-interferon gene have been obtained.
In addition to genes in the cells of living organisms, there are also independent genes in nature. They are called viruses if they can cause an infection. It turned out that the virus is nothing more than genetic material packed in a protein shell. The shell is a purely mechanical device, like a syringe, in order to package and then inject genes, and only genes, into the host cell and fall off. Then the viral genes in the cell begin to reproduce their RNA and their proteins on themselves. All this overwhelms the cell, it bursts, dies, and the virus in thousands of copies is released and infects other cells.
Illness, and sometimes even death, is caused by foreign, viral proteins. If the virus is "good", the person does not die, but can be ill all his life. A classic example is herpes, the virus of which is present in the body of 90% of people. This is the most adaptable virus, usually infecting a person in childhood and living in it all the time.
Thus, viruses are, in essence, biological weapons invented by evolution: a syringe filled with genetic material.
Now the example is already from modern biotechnology, an example of the operation with the germ cells of higher animals for the sake of noble goals. Humanity is experiencing difficulties with interferon, an important protein with anti-cancer and antiviral activity. Interferon is produced by an animal organism, including a human one. Alien, not human, interferon cannot be taken for the treatment of people, it is rejected by the body or is ineffective. A person produces too little interferon to be isolated for pharmacological purposes. Therefore, the following was done. The human interferon gene was introduced into a bacterium, which then multiplied and produced human interferon in large quantities in accordance with the human gene sitting in it. Now this already standard technique is used all over the world. In the same way, and for quite some time now, genetically engineered insulin has been produced. With bacteria, however, there are many difficulties in purifying the desired protein from bacterial impurities. Therefore, they begin to abandon them, developing methods for introducing the necessary genes into higher organisms. It's more difficult, but it provides tremendous benefits. Now, in particular, dairy production of the necessary proteins using pigs and goats is already widespread. The principle here, very briefly and simplified, is this. Egg cells are extracted from the animal and inserted into their genetic apparatus, under the control of animal milk protein genes, foreign genes that determine the production of the necessary proteins: interferon, or antibodies necessary for a person, or special food proteins. The eggs are then fertilized and returned to the body. Part of the offspring begins to produce milk containing the necessary protein, and it is already quite simple to isolate it from milk. It turns out much cheaper, safer and cleaner.
In the same way, cows were bred to give "women's" milk (cow's milk with the necessary human proteins), suitable for artificial feeding of human babies. And now this is a rather serious problem.
In general, we can say that in practical terms, humanity has reached a rather dangerous milestone. Learned how to influence genetic apparatus, including higher organisms. We learned how to direct, selective gene influence, the production of so-called transgenic organisms - organisms that carry any foreign genes. DNA is a substance that can be manipulated. In the last two or three decades, methods have emerged that can cut DNA in the right places and glue it with any other piece of DNA. Moreover, they can cut and paste not only certain ready-made genes, but also recombinants - combinations of different, including artificially created genes. This direction is called genetic engineering. Man has become a genetic engineer. In his hands, in the hands of a not so intellectually perfect being, there appeared boundless, gigantic possibilities - like the Lord God.
Modern cytology
New methods, especially electron microscopy, the use of radioactive isotopes, and high-speed centrifugation, are making great progress in studying the structure of the cell. In developing a unified concept of the physicochemical aspects of life, cytology is increasingly moving closer to other biological disciplines. At the same time, her classical methods, based on fixation, staining and studying cells under a microscope, still retain their practical value.
Cytological methods are used, in particular, in plant breeding to determine the chromosomal composition of plant cells. Such studies are of great help in planning experimental crossings and evaluating the results obtained. A similar cytological analysis is carried out on human cells: it allows you to identify some hereditary diseases associated with changes in the number and shape of chromosomes. Such an analysis, in combination with biochemical tests, is used, for example, in amniocentesis to diagnose hereditary defects in the fetus.
However, the most important application of cytological methods in medicine is the diagnosis of malignant neoplasms. In cancer cells, especially in their nuclei, specific changes occur. Malignant formations are nothing more than deviations in the normal development process due to the exit from the control of the systems that control development, primarily genetic ones. Cytology is a fairly simple and highly informative method for screening diagnostics of various manifestations of papillomavirus. This study is conducted in both men and women.
Description of work
Based on the latest scientific achievements Modern biological science gives the following definition of life: “Life is open self-regulating and self-reproducing systems of living organisms, built from complex biological polymers - proteins and nucleic acids” (I. I. Mechnikov).
Recent advances in biology have led to the emergence of fundamentally new directions in science. The discovery of the molecular structure of the structural units of heredity (genes) served as the basis for the creation of genetic engineering. With the help of its methods, organisms are created with new, including those not found in nature, combinations of hereditary traits and properties. It opens up opportunities for breeding new varieties of cultivated plants and highly productive animal breeds, creating effective medicines etc.
Achievements in biology in modern versions of the taxonomy of life
Based on the latest scientific achievements of modern biological science, the following definition of life is given: “Life is open self-regulating and self-reproducing systems of living organisms, built from complex biological polymers - proteins and nucleic acids” (I. I. Mechnikov).
Recent advances in biology have led to the emergence of fundamentally new directions in science. The discovery of the molecular structure of the structural units of heredity (genes) served as the basis for the creation of genetic engineering. With the help of its methods, organisms are created with new, including those not found in nature, combinations of hereditary traits and properties. It opens up opportunities for breeding new varieties of cultivated plants and highly productive animal breeds, creating effective drugs, etc.
Living nature arranged itself brilliantly simply and wisely. It has the only self-reproducing DNA molecule on which the life program is written, and more specifically, the entire synthesis process, the structure and function of proteins as the basic elements of life. In addition to preserving the life program, the DNA molecule performs another important function - its self-reproduction, copying create continuity between generations, the continuity of the thread of life. Once having arisen, life reproduces itself in a huge variety, which ensures its stability, adaptability to various environmental conditions and evolution.
Modern biotechnologies
Modern biology is an area of rapid and fantastic transformations in biotechnology.
Biotechnologies are based on the use of living organisms and biological processes in industrial production. On their basis, mass production of artificial proteins, nutrients and many other substances, superior to products of natural origin in many properties, has been mastered. The microbiological synthesis of enzymes, vitamins, amino acids, antibiotics, etc. is successfully developing. With the use of gene technologies and natural bioorganic materials, biologically active substances are synthesized - hormonal preparations and compounds that stimulate the immune system.
Modern biotechnology makes it possible to turn waste wood, straw and other plant materials into valuable nutritious proteins. It includes the process of hydrolysis of the intermediate product - cellulose - and the neutralization of the resulting glucose with the introduction of salts. The resulting glucose solution is a nutrient substrate for microorganisms - yeast fungi. As a result of the vital activity of microorganisms, a light brown powder is formed - a high-quality food product containing about 50% of raw protein and various vitamins. Sugar-containing solutions such as treacle stillage and sulfite liquor from pulp production can also serve as a nutrient medium for yeasts.
Some types of fungi convert oil, fuel oil and natural gas into protein-rich edible biomass. Thus, 10 tons of yeast biomass containing 5 tons of pure protein and 90 tons of diesel fuel can be obtained from 100 tons of crude fuel oil. The same amount of yeast is produced from 50 tons of dry wood or 30 thousand m3 of natural gas. To produce this amount of protein would require a herd of 10,000 cows, and to maintain them, huge areas of arable land are needed. industrial production proteins is fully automated, and yeast cultures grow thousands of times faster than cattle. One ton of nutritional yeast allows you to get about 800 kg of pork, 1.5-2.5 tons of poultry or 15-30 thousand eggs and save up to 5 tons of grain.
The practical application of the achievements of modern biology already at the present time makes it possible to obtain industrially significant amounts of biologically active substances.
Biotechnology, apparently, will take a leading position in the coming decades and, perhaps, will determine the face of civilization in the 21st century.
Gene technologies
Genetics is the most important area of modern biology.
On the basis of genetic engineering, modern biotechnology was born. There are now a huge number of firms doing business in this area in the world. They do everything from drugs, antibodies, hormones, food proteins to technical things - ultra-sensitive sensors (biosensors), computer microcircuits, chitin cones for good acoustic systems. Genetically engineered products are conquering the world, they are environmentally safe.
At the initial stage of the development of gene technologies, a number of biologically active compounds were obtained - insulin, interferon, etc. Modern gene technologies combine the chemistry of nucleic acids and proteins, microbiology, genetics, biochemistry and open up new ways to solve many problems in biotechnology, medicine and agriculture.
Gene technologies are based on the methods of molecular biology and genetics associated with the purposeful construction of new combinations of genes that do not exist in nature. The main operation of gene technology is to extract from the cells of an organism a gene encoding the desired product, or a group of genes, and combine them with DNA molecules that can multiply in the cells of another organism.
The DNA stored and working in the cell nucleus reproduces more than just itself. At the right moment, certain sections of DNA - genes - reproduce their copies in the form of a chemically similar polymer - RNA, ribonucleic acid, which in turn serve as templates for the production of many proteins necessary for the body. It is proteins that determine all the signs of living organisms. The main chain of events at the molecular level:
DNA -> RNA -> protein
This line contains the so-called central dogma of molecular biology.
Gene technologies have led to the development of modern methods for the analysis of genes and genomes, and they, in turn, to synthesis, i.e. to the construction of new, genetically modified microorganisms. To date, the nucleotide sequences of various microorganisms, including industrial strains, have been established, and those that are needed to study the principles of genome organization and to understand the mechanisms of microbial evolution. Industrial microbiologists, in turn, are convinced that knowledge of the nucleotide sequences of the genomes of industrial strains will allow them to be "programmed" so that they bring in a lot of income.
Cloning of eukaryotic (nuclear) genes in microbes is the fundamental method that led to the rapid development of microbiology. Fragments of the genomes of animals and plants are cloned in microorganisms for their analysis. To do this, artificially created plasmids are used as molecular vectors, gene carriers, as well as many other molecular entities for isolation and cloning.
With the help of molecular samples (DNA fragments with a certain sequence of nucleotides) it is possible to determine, say, whether donated blood is infected with the AIDS virus. And genetic technologies for identifying some microbes make it possible to monitor their spread, for example, inside a hospital or during epidemics.
Gene technologies for the production of vaccines are developing in two main directions. The first is the improvement of already existing vaccines and the creation of a combined vaccine, i.e. consisting of several vaccines. The second direction is obtaining vaccines against diseases: AIDS, malaria, stomach ulcers, etc.
Behind last years Gene technologies have significantly improved the efficiency of traditional producer strains. For example, in a fungal strain producing the antibiotic cephalosporin, the number of genes encoding expandase, the activity that determines the rate of cephalosporin synthesis, has been increased. As a result, antibiotic production increased by 15-40%.
Purposeful work is being carried out to genetically modify the properties of microbes used in the production of bread, cheese making, the dairy industry, brewing and winemaking in order to increase the resistance of production strains, increase their competitiveness in relation to harmful bacteria and improve the quality of the final product.
Genetically modified microbes are beneficial in the fight against harmful viruses and germs and insects. For example:
- plant resistance to herbicides, which is important for controlling weeds that clog fields and reduce the yield of cultivated plants. Herbicide-resistant varieties of cotton, corn, rapeseed, soybean, sugar beet, wheat and other plants have been obtained and are being used.
- resistance of plants to insect pests. Development of the delta-endotoxin protein produced by different strains of the bacterium Bacillus turingensis. This protein is toxic to many insect species and is safe for mammals, including humans.
- resistance of plants to viral diseases. To do this, genes that block the reproduction of viral particles in plants, such as interferon, nucleases, are introduced into the plant cell genome. Transgenic plants of tobacco, tomatoes and alfalfa with the beta-interferon gene have been obtained.
In addition to genes in the cells of living organisms, there are also independent genes in nature. They are called viruses if they can cause an infection. It turned out that the virus is nothing more than genetic material packed in a protein shell. The shell is a purely mechanical device, like a syringe, in order to package and then inject genes, and only genes, into the host cell and fall off. Then the viral genes in the cell begin to reproduce their RNA and their proteins on themselves. All this overwhelms the cell, it bursts, dies, and the virus in thousands of copies is released and infects other cells.
Illness, and sometimes even death, is caused by foreign, viral proteins. If the virus is "good", the person does not die, but can be ill all his life. A classic example is herpes, the virus of which is present in the body of 90% of people. This is the most adaptable virus, usually infecting a person in childhood and living in it all the time.
Thus, viruses are, in essence, biological weapons invented by evolution: a syringe filled with genetic material.
Now the example is already from modern biotechnology, an example of the operation with the germ cells of higher animals for the sake of noble goals. Humanity is experiencing difficulties with interferon, an important protein with anti-cancer and antiviral activity. Interferon is produced by an animal organism, including a human one. Alien, not human, interferon cannot be taken for the treatment of people, it is rejected by the body or is ineffective. A person produces too little interferon to be isolated for pharmacological purposes. Therefore, the following was done. The human interferon gene was introduced into a bacterium, which then multiplied and large quantities produced human interferon in accordance with the human gene sitting in it. Now this already standard technique is used all over the world. In the same way, and for quite some time now, genetically engineered insulin has been produced. With bacteria, however, there are many difficulties in purifying the desired protein from bacterial impurities. Therefore, they begin to abandon them, developing methods for introducing the necessary genes into higher organisms. It's more difficult, but it provides tremendous benefits. Now, in particular, dairy production of the necessary proteins using pigs and goats is already widespread. The principle here, very briefly and simplified, is this. Egg cells are extracted from the animal and inserted into their genetic apparatus, under the control of animal milk protein genes, foreign genes that determine the production of the necessary proteins: interferon, or antibodies necessary for a person, or special food proteins. The eggs are then fertilized and returned to the body. Part of the offspring begins to produce milk containing the necessary protein, and it is already quite simple to isolate it from milk. It turns out much cheaper, safer and cleaner.
In the same way, cows were bred to give "women's" milk (cow's milk with the necessary human proteins), suitable for artificial feeding of human babies. And now this is a rather serious problem.
In general, we can say that in practical terms, humanity has reached a rather dangerous milestone. We learned how to influence the genetic apparatus, including higher organisms. We learned how to direct, selective gene influence, the production of so-called transgenic organisms - organisms that carry any foreign genes. DNA is a substance that can be manipulated. In the last two or three decades, methods have emerged that can cut DNA into right places and glue with any other piece of DNA. Moreover, they can cut and paste not only certain ready-made genes, but also recombinants - combinations of different, including artificially created genes. This direction is called genetic engineering. Man has become a genetic engineer. In his hands, in the hands of a not so intellectually perfect being, there appeared boundless, gigantic possibilities - like the Lord God.
Modern cytology
New methods, especially electron microscopy, the use of radioactive isotopes, and high-speed centrifugation, are making great progress in studying the structure of the cell. In developing a unified concept of the physicochemical aspects of life, cytology is increasingly moving closer to other biological disciplines. At the same time, her classical methods based on fixation, staining and microscopic examination of cells still retain their practical value.
Cytological methods are used, in particular, in plant breeding to determine the chromosomal composition of plant cells. Such studies are of great help in planning experimental crossings and evaluating the results obtained. A similar cytological analysis is carried out on human cells: it allows you to identify some hereditary diseases associated with changes in the number and shape of chromosomes. Such an analysis, in combination with biochemical tests, is used, for example, in amniocentesis to diagnose hereditary defects in the fetus.
However, the most important application of cytological methods in medicine is the diagnosis of malignant neoplasms. In cancer cells, especially in their nuclei, specific changes occur. Malignant formations are nothing more than deviations in the normal development process due to the exit from the control of the systems that control development, primarily genetic ones. Cytology is a fairly simple and highly informative method for screening diagnostics of various manifestations of papillomavirus. This study is conducted in both men and women.
Cloning
Cloning is a process in which a living being is produced from a single cell taken from another living being.
Cloning is usually defined as the production of cells or organisms with the same nuclear genomes as another cell or organism. Accordingly, by cloning, you can create any living organism or part of it, identical to an existing one, or etc.
The most important discoveries in biology
1. Microorganisms (1674)
Using a microscope, Anton van Leeuwenhoek accidentally discovers microorganisms in a drop of water. His observations laid the foundation for the science of bacteriology and microbiology.
2. Cell nucleus (1831)
In studying the orchid, botanist Robert Brown describes the structure within the cells, which he calls the "nucleus".
3. Archaea (1977)
Carl Wese discovers bacteria without a nucleus. Many organisms classified in the new kingdom Archaea are extremophiles. Some of them live in very high or low temperatures, others in very salty, acidic or alkaline water.
4. Cell division (1879)
Walter Flemming is careful to note that animal cells divide in stages, which constitutes the process of mitosis. Eduard Strasburger independently defines a similar process of cell division in plant cells.
Economic relationships are studied by science - econometrics. As a rule, general global processes represent a deeply non-linear system of interrelations. However, according to the theory big numbers it is possible to predict the trend based on the analysis of the main determining factors.
Programming allows you to calculate the average values of processes: an online statistics calculator allows you to do this quite quickly.
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5 Sex Cells (1884)
August Weismann determines that germ cells must be divided in different ways in order to end up with only half of the chromosome set. This special type of germ cells is called meiosis. Weismann's experiments with jellyfish led him to the conclusion that changes in the offspring result from the combination of matter from the parents. He refers to this substance as "germ plasm".
6. Cell differentiation (late 19th century)
Some scientists are involved in the discovery of cell differentiation, which ultimately leads to the isolation of human embryonic stem cells. In differentiation, the cell turns into one of the many types of cells that make up the body, such as lung, skin, or muscle.
Some genes are activated while others are inactivated so that the cell develops structurally to perform a specific function. Cells that are not yet differentiated and have the potential to become any type of cell are called stem cells.
7. Mitochondria (late 19th century to present)
Scientists have found that mitochondria are the powerhouse of the cell. These small structures in animal cells are responsible for the metabolism and transformation of food in cells into chemical substances that can be used. They were originally thought to be specialized bacteria with their own DNA.
8. Krebs cycle (1937)
Hans Krebs defines the stages of the state of the cell, necessary for the conversion of sugar, fats and proteins into energy. Also known as the citric acid cycle, this is a series of chemical reactions using oxygen as part of cellular respiration. The cycle contributes to the breakdown of carbohydrates, fats and proteins into carbon dioxide and water.
9. Neurotransmission (late 19th - early 20th century)
Scientists have discovered neurotransmitters - bodies that transmit signals from one nerve cell to another through chemicals or electrical signals.
10. Hormones (1903)
William Bayliss and Ernest Starling give the hormone its name and show their role as chemical messengers. They specifically describe secretin, a substance released into the blood from the duodenum (between the stomach and small intestine) that stimulates the secretion of gastric juice from the pancreas into the intestines.
11. Photosynthesis (1770)
Jan Ingenhousz discovers that plants react differently to sunlight than they do to shade. This laid the foundation for understanding photosynthesis. Photosynthesis is the process by which plants, algae and some bacteria convert light energy into chemical energy. In plants, the leaves take in carbon dioxide while the roots take in water. sunlight catalyzes a reaction that leads to the production of glucose (food for plants) and oxygen, which is a waste product, enters environment. Almost all life on Earth is ultimately dependent on this process.
12. Ecosystem (1935)
Arthur George Tensley
Arthur George Tensley coined the term ecosystem. Ecosystems are defined as a dynamic and complex whole that acts as an ecological unit.
13. Tropical biodiversity (15th century to present)
On expeditions around the world, early European explorers reported a much greater diversity of species in the tropics. The answer to the question why this is so allows scientists today to protect life on Earth.
