Everyone knows well that biology is the science of life. Currently, it represents the totality of sciences about living nature. Biology studies all manifestations of life: the structure, functions, development and origin of living organisms, their relationships in natural communities with their environment and with other living organisms.
Since man began to realize his difference from the animal world, he began to study the world around him. At first his life depended on it. Primitive people needed to know which living organisms could be eaten, used as medicine, to make clothing and homes, and which of them were poisonous or dangerous.
With the development of civilization, man was able to afford the luxury of engaging in science for educational purposes.
Studies of the culture of ancient peoples have shown that they had extensive knowledge about plants and animals and used them widely in everyday life.?
Modern biology is a complex science, which is characterized by the interpenetration of ideas and methods of various biological disciplines, as well as other sciences - primarily physics, chemistry and mathematics.
Main directions of development of modern biology. Currently, three directions in biology can be roughly distinguished.
Firstly, this is classical biology. It is represented by natural scientists who study the diversity of living nature. They objectively observe and analyze everything that happens in living nature, study living organisms and classify them. It is wrong to think that in classical biology all discoveries have already been made. In the second half of the 20th century. not only many new species were described, but also large taxa were discovered, up to kingdoms (Pogonophora) and even superkingdoms (Archebacteria, or Archaea). These discoveries forced scientists to take a fresh look at the entire history of the development of living nature. For real natural scientists, nature is its own value. Every corner of our planet is unique for them. That is why they are always among those who acutely sense the danger to the nature around us and actively advocate for its protection.
The second direction is evolutionary biology. In the 19th century, the author of the theory of natural selection, Charles Darwin, began as an ordinary naturalist: he collected, observed, described, traveled, revealing the secrets of living nature. However, the main result of his work, which made him a famous scientist, was the theory that explains organic diversity.
Currently, the study of the evolution of living organisms is actively continuing. The synthesis of genetics and evolutionary theory led to the creation of the so-called synthetic theory of evolution. But even now there are still many unresolved questions, the answers to which evolutionary scientists are looking for.
Created at the beginning of the 20th century. Our outstanding biologist Alexander Ivanovich Oparin's first scientific theory of the origin of life was purely theoretical. Experimental studies of this problem are currently being actively conducted and, thanks to the use of advanced physicochemical methods, important discoveries have already been made and new interesting results can be expected.
New discoveries made it possible to supplement the theory of anthropogenesis. But the transition from the animal world to humans still remains one of the biggest mysteries of biology.
The third direction is physical and chemical biology, which studies the structure of living objects using modern physical and chemical methods. This is a rapidly developing area of biology, important both theoretically and practically. It is safe to say that new discoveries await us in physical and chemical biology that will allow us to solve many problems facing humanity,
Development of biology as a science. Modern biology has its roots in antiquity and is associated with the development of civilization in the Mediterranean countries. We know the names of many outstanding scientists who contributed to the development of biology. Let's name just a few of them.
Hippocrates (460 - ca. 370 BC) gave the first relatively detailed description of the structure of humans and animals, and pointed out the role of the environment and heredity in the occurrence of diseases. He is considered the founder of medicine.
Aristotle (384-322 BC) divided the world around us into four kingdoms: the inanimate world of earth, water and air; world of plants; the animal world and the human world. He described many animals and laid the foundation for taxonomy. The four biological treatises he wrote contained almost all the information about animals known at that time. Aristotle's merits are so great that he is considered the founder of zoology.
Theophrastus (372-287 BC) studied plants. He described more than 500 plant species, provided information about the structure and reproduction of many of them, and introduced many botanical terms into use. He is considered the founder of botany.
Guy Pliny the Elder (23-79) collected information about living organisms known by that time and wrote 37 volumes of the Natural History encyclopedia. Almost until the Middle Ages, this encyclopedia was the main source of knowledge about nature.
Claudius Galen made extensive use of mammal dissections in his scientific research. He was the first to make comparative
anatomical description of man and monkey. Studied the central and peripheral nervous system. Historians of science consider him the last great biologist of antiquity.
In the Middle Ages, the dominant ideology was religion. Like other sciences, biology during this period had not yet emerged as an independent field and existed in the general mainstream of religious and philosophical views. And although the accumulation of knowledge about living organisms continued, biology as a science in that period can only be spoken of conditionally.
The Renaissance is a transition from the culture of the Middle Ages to the culture of modern times. The radical socio-economic transformations of that time were accompanied by new discoveries in science.
The most famous scientist of this era, Leonardo da Vinci (1452-1519), made a certain contribution to the development of biology.
He studied the flight of birds, described many plants, ways of connecting bones in joints, the activity of the heart and the visual function of the eye, the similarity of human and animal bones.
In the second half of the 15th century. natural science knowledge begins to develop rapidly. This was facilitated by geographical discoveries, which made it possible to significantly expand information about animals and plants. Rapid accumulation of scientific knowledge about living organisms
led to the division of biology into separate sciences.
In the XVI-XVII centuries. Botany and zoology began to develop rapidly.
The invention of the microscope (early 17th century) made it possible to study the microscopic structure of plants and animals. Microscopically small living organisms - bacteria and protozoa - were discovered, invisible to the naked eye.
A great contribution to the development of biology was made by Carl Linnaeus, who proposed a system of classification of animals and plants.
Karl Maksimovich Baer (1792-1876) in his works formulated the basic principles of the theory of homologous organs and the law of germinal similarity, which laid the scientific foundations of embryology.
In 1808, in his work “Philosophy of Zoology,” Jean Baptiste Lamarck raised the question of the causes and mechanisms of evolutionary transformations and outlined the first theory of evolution.
The cell theory played a huge role in the development of biology, which scientifically confirmed the unity of the living world and served as one of the prerequisites for the emergence of Charles Darwin's theory of evolution. The authors of the cell theory are considered to be the zoologist Theodor Schwann (1818-1882) and the botanist Matthias Jakob Schleiden (1804-1881).
Based on numerous observations, Charles Darwin published his main work in 1859, “On the Origin of Species by Means of Natural Selection, or the Preservation of Favored Breeds in the Struggle for Life.” In it, he formulated the main provisions of the theory of evolution, proposed mechanisms of evolution and ways of evolutionary transformations of organisms.
The 20th century began with the rediscovery of Gregor Mendel's laws, which marked the beginning of the development of genetics as a science.
In the 40-50s of the XX century. In biology, ideas and methods of physics, chemistry, mathematics, cybernetics and other sciences began to be widely used, and microorganisms were used as objects of research. As a result, biophysics, biochemistry, molecular biology, radiation biology, bionics, etc. arose and began to rapidly develop as independent sciences. Research in space contributed to the emergence and development of space biology.
In the 20th century a direction of applied research appeared - biotechnology. This direction will undoubtedly develop rapidly in the 21st century. You will learn more about this direction of development of biology when studying the chapter “Fundamentals of selection and biotechnology”.
Currently, biological knowledge is used in all spheres of human activity: in industry and agriculture, medicine and energy.
Ecological research is extremely important. We finally began to realize that the fragile balance that exists on our small planet can be easily destroyed. Humanity is faced with a grandiose task - preserving the biosphere in order to maintain the conditions of existence and development of civilization. It is impossible to solve it without biological knowledge and special research. Thus, at present, biology has become a real productive force and a rational scientific basis for the relationship between man and nature.
MICROSCOPE
REPORT on Biology for a 6th grade student
For a long time, man lived surrounded by invisible creatures, used the products of their vital activity (for example, when baking bread from sour dough, preparing wine and vinegar), suffered when these creatures caused illness or spoiled food supplies, but was not aware of their presence . I didn’t suspect because I didn’t see, and I didn’t see because the size of these micro creatures lay much below the limit of visibility of which the human eye is capable. It is known that a person with normal vision at an optimal distance (25-30 cm) can distinguish an object measuring 0.07–0.08 mm in the form of a point. A person cannot notice smaller objects. This is determined by the structural features of his organ of vision.
Around the same time that space exploration with telescopes began, the first attempts were made to reveal the mysteries of the microworld using lenses. Thus, during archaeological excavations in Ancient Babylon, biconvex lenses were found - the simplest optical instruments. The lenses were made from polished rock crystal We can consider that with their invention, man took the first step on the path to the microworld.
The easiest way to enlarge the image of a small object is to observe it with a magnifying glass. A magnifying glass is a converging lens with a small focal length (usually no more than 10 cm) inserted into the handle.
Telescope creator Galileo V 1610
year, he discovered that when greatly extended, his telescope made it possible to greatly magnify small objects. It can be considered inventor of the microscope consisting of positive and negative lenses.
A more advanced tool for observing microscopic objects is simple microscope. It is not known exactly when these devices appeared. At the very beginning of the 17th century, several such microscopes were made by a spectacle maker. Zachariah Jansen from Middelburg.
In the essay A. Kircher, published in 1646 year, contains a description simple microscope, named by him "flea glass". It consisted of a magnifying glass embedded in a copper base, on which an object table was mounted, which served to place the object in question; at the bottom there was a flat or concave mirror that reflected the sun's rays onto the object and thus illuminated it from below. The magnifying glass was moved by means of a screw to the stage until the image became clear and distinct.
First outstanding discoveries were made just using a simple microscope. In the middle of the 17th century, the Dutch naturalist achieved brilliant success Anthony Van Leeuwenhoek. Over the years, Leeuwenhoek perfected his ability to make tiny (sometimes less than 1 mm in diameter) biconvex lenses, which he made from a small glass ball, in turn obtained by melting a glass rod in a flame. This glass bead was then ground using a primitive grinding machine. Throughout his life, Leeuwenhoek made at least 400 such microscopes. One of them, kept in the University Museum in Utrecht, gives more than 300 times magnification, which was a huge success for the 17th century.
At the beginning of the 17th century there appeared compound microscopes, composed of two lenses. The inventor of such a complex microscope is not exactly known, but many facts indicate that he was a Dutchman Cornelius Drebel, who lived in London and was in the service of the English King James I. In a compound microscope there was two glasses: one - the lens - facing the object, the other - the eyepiece - facing the eye of the observer. In the first microscopes, the lens was a biconvex glass, which gave a real, magnified, but inverted image. This image was examined with the help of an eyepiece, which thus played the role of a magnifying glass, but only this magnifying glass served to enlarge not the object itself, but its image.
IN 1663 year microscope Drebel was improved English physicist Robert Hooke, who introduced a third lens into it, called the collective. This type of microscope gained great popularity, and most microscopes of the late 17th - first half of the 8th century were built according to its design.
Microscope device
A microscope is an optical instrument designed to examine magnified images of micro-objects that are invisible to the naked eye.
The main parts of a light microscope (Fig. 1) are the lens and the eyepiece, enclosed in a cylindrical body - a tube. Most models intended for biological research are equipped with three lenses with different focal lengths and a rotating mechanism designed for quick change - a turret, often called a turret. The tube is located on the top of a massive tripod, which includes a tube holder. Just below the lens (or a turret with several lenses) there is a stage on which slides with the samples under study are mounted. Sharpness is adjusted using the coarse and fine adjustment screw, which allows you to change the position of the stage relative to the lens.
In order for the sample under study to have sufficient brightness for comfortable observation, microscopes are equipped with two more optical units (Fig. 2) - an illuminator and a condenser. The illuminator creates a stream of light that illuminates the drug being studied. In classical light microscopes, the design of the illuminator (built-in or external) involves a low-voltage lamp with a thick filament, a collecting lens and a diaphragm that changes the diameter of the light spot on the sample. The condenser, which is a collecting lens, is designed to focus the illuminator beams on the sample. The condenser also has an iris diaphragm (field and aperture), with which the light intensity is adjusted.
When working with objects that transmit light (liquids, thin sections of plants, etc.), they are illuminated with transmitted light - the illuminator and condenser are located under the object stage. Opaque samples need to be illuminated from the front. To do this, the illuminator is placed above the object stage, and its rays are directed to the object through the lens using a translucent mirror.
The illuminator can be passive, active (lamp) or consist of both elements. The simplest microscopes do not have lamps to illuminate samples. Under the table they have a two-way mirror, one side of which is flat and the other is concave. In daylight, if the microscope is placed near a window, you can get pretty good illumination using a concave mirror. If the microscope is located in a dark room, a flat mirror and an external illuminator are used for illumination.
The magnification of a microscope is equal to the product of the magnification of the objective and the eyepiece. With an eyepiece magnification of 10 and an objective magnification of 40, the total magnification factor is 400. Typically, a research microscope kit includes objectives with a magnification of 4 to 100. A typical set of microscope lenses for amateur and educational research (x 4, x 10 and x 40) provides increase from 40 to 400.
Resolution is another important characteristic of a microscope, determining its quality and clarity of the image it forms. The higher the resolution, the more fine details can be seen at high magnification. In connection with resolution, they talk about “useful” and “useless” magnification. “Useful” is the maximum magnification at which maximum image detail is provided. Further magnification (“useless”) is not supported by the resolution of the microscope and does not reveal new details, but can negatively affect the clarity and contrast of the image. Thus, the limit of useful magnification of a light microscope is limited not by the general magnification factor of the objective and eyepiece - it can be made as large as desired - but by the quality of the optical components of the microscope, that is, the resolution.
The microscope includes three main functional parts:
1. Lighting part
Designed to create a light flux that allows you to illuminate an object in such a way that subsequent parts of the microscope perform their functions with extreme precision. The illuminating part of a transmitted light microscope is located behind the object under the lens in direct microscopes and in front of the object above the lens in inverted microscopes.
The lighting part includes a light source (lamp and electrical power supply) and an optical-mechanical system (collector, condenser, field and aperture adjustable/iris diaphragms).
2. Reproducing part
Designed to reproduce an object in the image plane with the image quality and magnification required for research (i.e., to construct an image that would reproduce the object as accurately as possible and in all details with the resolution, magnification, contrast and color rendition corresponding to the microscope optics).
The reproducing part provides the first stage of magnification and is located after the object to the microscope image plane. The reproducing part includes a lens and an intermediate optical system.
Modern microscopes of the latest generation are based on optical lens systems corrected for infinity.
This additionally requires the use of so-called tube systems, which “collect” parallel beams of light emerging from the lens in the microscope image plane.
3. Visualization part
Designed to obtain a real image of an object on the retina of the eye, photographic film or plate, on the screen of a television or computer monitor with additional magnification (second stage of magnification).
The visualizing part is located between the image plane of the lens and the eyes of the observer (camera, photo camera).
The imaging part includes a monocular, binocular or trinocular imaging head with an observation system (eyepieces that work like a magnifying glass).
In addition, this part includes additional magnification systems (magnification wholesaler/change systems); projection attachments, including discussion attachments for two or more observers; drawing apparatus; image analysis and documentation systems with corresponding matching elements (photo channel).
A microscope is a unique device designed to magnify microimages and measure the size of objects or structural formations observed through the lens. This development is amazing, and the significance of the invention of the microscope is extremely great, because without it some areas of modern science would not exist. And from here in more detail.
A microscope is a device related to a telescope, which is used for completely different purposes. With its help, it is possible to examine the structure of objects that are invisible to the eye. It allows you to determine the morphological parameters of microformations, as well as evaluate their volumetric location. Therefore, it is even difficult to imagine what significance the invention of the microscope had, and how its appearance influenced the development of science.
History of the microscope and optics
Today it is difficult to answer who first invented the microscope. This issue will probably be as widely discussed as the creation of a crossbow. However, unlike weapons, the invention of the microscope actually occurred in Europe. And by whom exactly is still unknown. The likelihood that the discoverer of the device was Hans Jansen, a Dutch eyeglass maker, is quite high. His son, Zacharias Jansen, made a claim in 1590 that he and his father had constructed a microscope.
But already in 1609, another mechanism appeared, which was created by Galileo Galilei. He called it occhiolino and presented it to the public at the Accademia Nazionale dei Lincei. Proof that a microscope could already have been used at that time is the sign on the seal of Pope Urban III. It is believed to represent a modification of an image obtained by microscopy. Galileo Galilei's light microscope (composite) consisted of one convex and one concave lens.
Improvement and implementation into practice
Just 10 years after Galileo's invention, Cornelius Drebbel created a compound microscope with two convex lenses. And later, that is, towards the end, Christian Huygens developed a two-lens eyepiece system. They are still produced today, although they lack the breadth of visibility. But, more importantly, using such a microscope in 1665, a study was carried out on a section of a cork oak tree, where the scientist saw the so-called honeycombs. The result of the experiment was the introduction of the concept of "cell".
Another father of the microscope, Anthony van Leeuwenhoek, only reinvented it, but managed to attract the attention of biologists to the device. And after this it became clear what significance the invention of the microscope had for science, because it allowed the development of microbiology. Probably, the mentioned device significantly accelerated the development of natural sciences, because until man saw microbes, he believed that diseases originate from uncleanliness. And in science the concepts of alchemy and vitalistic theories of the existence of living things and the spontaneous generation of life reigned.
Leeuwenhoek microscope
The invention of the microscope is a unique event in the science of the Middle Ages, because thanks to the device it was possible to find many new subjects for scientific discussion. Moreover, many theories have been destroyed thanks to microscopy. And this is the great merit of Anthony van Leeuwenhoek. He was able to improve the microscope so that it allowed cells to be seen in detail. And if we consider the issue in this context, Leeuwenhoek is indeed the father of this type of microscope.
Device structure
The light itself was a plate with a lens capable of magnifying the objects in question many times over. This plate with a lens had a tripod. Using it, it was mounted on a horizontal table. By directing the lens to the light and placing the material under study between it and the candle flame, it was possible to see. Moreover, the first material that Antonie van Leeuwenhoek studied was dental plaque. In it, the scientist saw many creatures, which he could not name yet.
The uniqueness of the Leeuwenhoek microscope is amazing. The composite models available at that time did not provide high image quality. Moreover, the presence of two lenses only intensified the defects. Therefore, it took more than 150 years until the compound microscopes originally developed by Galileo and Drebbel began to produce the same image quality as Leeuwenhoek's device. Anthony van Leeuwenhoek himself is still not considered the father of the microscope, but he is rightfully a recognized master of microscopy of native materials and cells.
Invention and improvement of lenses
The very concept of a lens already existed in Ancient Rome and Greece. For example, in Greece it was possible to light a fire using convex glass. And in Rome, the properties of glass vessels filled with water have long been noticed. They made it possible to enlarge images, although not many times. The further development of lenses is unknown, although it is obvious that progress could not stand still.
It is known that in the 16th century the use of glasses came into practice in Venice. This is confirmed by the facts about the presence of glass grinding machines, which made it possible to obtain lenses. There were also drawings of optical instruments, which were mirrors and lenses. The authorship of these works belongs to Leonardo da Vinci. But even earlier, people worked with magnifying glasses: back in 1268, Roger Bacon put forward the idea of creating a spyglass. Later it was implemented.
Obviously, the author of the lens did not belong to anyone. But this was observed until Carl Friedrich Zeiss took up optics. In 1847 he began producing microscopes. His company then became a leader in the development of optical glasses. It exists to this day, remaining the main one in the industry. All companies that produce photo and video cameras, optical sights, rangefinders, telescopes and other devices cooperate with it.
Improving microscopy
The history of the invention of the microscope is striking when studied in detail. But no less interesting is the history of further improvement of microscopy. New ones began to appear, and the scientific thought that gave rise to them sank deeper and deeper. Now the scientist’s goal was not only to study microbes, but also to consider smaller components. These are molecules and atoms. Already in the 19th century they could be studied by X-ray diffraction analysis. But science demanded more.
So, already in 1863, researcher Henry Clifton Sorby developed a polarizing microscope to study meteorites. And in 1863, Ernst Abbe developed the theory of the microscope. It was successfully adopted by Carl Zeiss. Due to this, his company has developed into a recognized leader in the optical instruments industry.
But soon 1931 came - the time of the creation of the electron microscope. It has become a new type of device that allows you to see much more than light. It did not use photons or polarized light for transmission, but electrons - particles much smaller than the simplest ions. It was the invention of the electron microscope that allowed the development of histology. Now scientists have gained complete confidence that their judgments about the cell and its organelles are indeed correct. However, only in 1986 was the Nobel Prize awarded to the creator of the electron microscope, Ernst Ruska. Moreover, already in 1938, James Hiller built a transmission electron microscope.
The latest types of microscopes
Science, after the successes of many scientists, developed more and more quickly. Therefore, the goal dictated by new realities was the need to develop a highly sensitive microscope. And already in 1936, Erwin Müller produced a field emission device. And in 1951, another device was produced - a field ion microscope. Its importance is extreme because it allowed scientists to see atoms for the first time. And in addition to this, in 1955, Jerzy Nomarski developed the theoretical foundations of differential interference contrast microscopy.
Improving the latest microscopes
The invention of the microscope is not yet a success, because in principle it is not difficult to make ions or photons pass through biological media and then examine the resulting image. But the issue of improving the quality of microscopy was really important. And after these conclusions, scientists created a fly-by mass analyzer, which was called a scanning ion microscope.
This device made it possible to scan a single atom and obtain data on the three-dimensional structure of the molecule. Together with this method, it has been possible to significantly speed up the process of identifying many substances found in nature. And already in 1981, a scanning tunnel microscope was introduced, and in 1986 - an atomic force microscope. 1988 is the year of the invention of the scanning electrochemical tunnel microscope. And the latest and most useful is the Kelvin force probe. It was developed in 1991.
Assessing the global significance of the invention of the microscope
Beginning in 1665, when Leeuwenhoek began processing glass and producing microscopes, the industry developed and became more complex. And when wondering what the significance of the invention of the microscope was, it is worth considering the main achievements of microscopy. So, this method made it possible to examine the cell, which served as another impetus for the development of biology. Then the device made it possible to discern the organelles of the cell, which made it possible to formulate patterns of cellular structure.
The microscope then made it possible to see the molecule and atom, and later scientists were able to scan their surface. Moreover, through a microscope you can even see electron clouds of atoms. Since electrons move at the speed of light around the nucleus, it is completely impossible to examine this particle. Despite this, one should understand the significance of the invention of the microscope. He made it possible to see something new that cannot be seen with the eye. This is an amazing world, the study of which has brought man closer to modern achievements in physics, chemistry and medicine. And it’s worth all the work.
Nowadays, modern technologies are actively used in many areas of human activity. For example, in medicine there are already many devices that help put a person on his feet. But still, despite the big leap in the development of technology, there are many tools in medicine that have no analogues and which cannot be replaced with something else.
One of these instruments is a research biological microscope, which is actively used both in clinical practice and in the microbiological laboratory. Even modern instruments do not have the functions and capabilities that a microscope has, for example, for microbiological research or analysis of blood cells.
Today, biomedical microscopes are the most widespread type of optical technology. These tools can be used in any research that involves the study of objects of natural origin. Microscopes of this type are divided into two types: research and for biological laboratories. And also for routine and working ones. Biological microscopes are mainly used in various research centers, scientific institutions or hospitals.
I would also like to talk about binocular microscopes, which are a new stage in the evolution of these instruments. These devices have two eyepieces, which makes it much easier to work, and the work becomes more comfortable.
Today it is simply irreplaceable in hospitals or scientific laboratories. These microscopes will be a good purchase for higher education students who simply need practice in various academic works to gain experience.
With the help of two eyepieces it will be very easy to examine the experimental object, and, thanks to the eyepieces, the quality of the object being examined will increase several times. One of the main advantages of this device is that you can attach modern cameras or cameras to it, and ultimately get pictures of the object, or microscopic photography.
When you choose this device for yourself, first of all pay attention to the following details, parameters and features: a revolver with several lenses, lighting parameters, methods of moving the table. In addition, the microscope can be equipped with additional accessories, such as lamps, lenses, eyepieces, etc.
This is the science of life. Currently, it represents the totality of sciences about living nature.
Biology studies all manifestations of life: structure, functions, development and origin living organisms, their relationships in natural communities with the environment and with other living organisms.
Since man began to realize his difference from the animal world, he began to study the world around him.
At first his life depended on it. Primitive people needed to know which living organisms could be eaten, used as medicine, to make clothing and homes, and which of them were poisonous or dangerous.
With the development of civilization, man was able to afford the luxury of engaging in science for educational purposes.
Research The cultures of ancient peoples showed that they had extensive knowledge about plants and animals and widely used them in everyday life.
Modern biology - complex the science, which is characterized by the interpenetration of ideas and methods of various biological disciplines, as well as other sciences - primarily physics, chemistry and mathematics.
Main directions of development of modern biology. Currently, three directions in biology can be roughly distinguished.
Firstly, this is classical biology. It is represented by natural scientists who study the diversity of living things. nature. They objectively observe and analyze everything that happens in living nature, study living organisms and classify them. It is wrong to think that in classical biology all discoveries have already been made.
In the second half of the 20th century. not only many new species were described, but also large taxa were discovered, up to kingdoms (Pogonophora) and even superkingdoms (Archebacteria, or Archaea). These discoveries forced scientists to take a new look at the whole history of development living nature, For real natural scientists, nature is its own value. Every corner of our planet is unique for them. That is why they are always among those who acutely sense the danger to the nature around us and actively advocate for its protection.
The second direction is evolutionary biology.
In the 19th century the author of the theory of natural selection, Charles Darwin, began as an ordinary naturalist: he collected, observed, described, traveled, revealing the secrets of living nature. However, the main result of it work What made him a famous scientist was the theory that explained organic diversity.
Currently, the study of the evolution of living organisms is actively continuing. The synthesis of genetics and evolutionary theory led to the creation of the so-called synthetic theory of evolution. But even now there are still many unresolved questions, the answers to which evolutionary scientists are looking for.
Created at the beginning of the 20th century. Our outstanding biologist Alexander Ivanovich Oparin's first scientific theory of the origin of life was purely theoretical. Experimental studies of this problem are currently being actively conducted and, thanks to the use of advanced physicochemical methods, important discoveries have already been made and new interesting results can be expected.
New discoveries made it possible to supplement the theory of anthropogenesis. But the transition from the animal world to humans still remains one of the biggest mysteries of biology.
The third direction is physical and chemical biology, which studies the structure of living objects using modern physical and chemical methods. This is a rapidly developing area of biology, important both theoretically and practically. It is safe to say that new discoveries await us in physical and chemical biology that will allow us to solve many problems facing humanity.
Development of biology as a science. Modern biology has its roots in antiquity and is associated with the development of civilization in the Mediterranean countries. We know the names of many outstanding scientists who contributed to the development of biology. Let's name just a few of them.
Hippocrates (460 - ca. 370 BC) gave the first relatively detailed description of the structure of humans and animals, and pointed out the role of the environment and heredity in the occurrence of diseases. He is considered the founder of medicine.
Aristotle (384-322 BC) divided the world around us into four kingdoms: the inanimate world of earth, water and air; world of plants; the animal world and the human world. He described many animals and laid the foundation for taxonomy. The four biological treatises he wrote contained almost all the information about animals known at that time. Aristotle's merits are so great that he is considered the founder of zoology.
Theophrastus (372-287 BC) studied plants. He described more than 500 plant species, provided information about the structure and reproduction of many of them, and introduced many botanical terms into use. He is considered the founder of botany.
Guy Pliny the Elder (23-79) collected information about living organisms known at that time and wrote 37 volumes of the Natural History encyclopedia. Almost until the Middle Ages, this encyclopedia was the main source of knowledge about nature.
Claudius Galen made extensive use of mammal dissections in his scientific research. He was the first to make a comparative anatomical description of man and monkey. Studied the central and peripheral nervous system. Historians of science consider him the last great biologist of antiquity.
In the Middle Ages, the dominant ideology was religion. Like other sciences, biology during this period had not yet emerged as an independent field and existed in the general mainstream of religious and philosophical views. And although the accumulation of knowledge about living organisms continued, biology as a science in that period can only be spoken of conditionally.
The Renaissance is a transition from the culture of the Middle Ages to the culture of modern times. The radical socio-economic transformations of that time were accompanied by new discoveries in science.
The most famous scientist of this era, Leonardo da Vinci (1452 - 1519), made a certain contribution to the development of biology.
He studied the flight of birds, described many plants, ways of connecting bones in joints, the activity of the heart and the visual function of the eye, the similarity of human and animal bones.
In the second half of the 15th century. natural science knowledge begins to develop rapidly. This was facilitated by geographical discoveries, which made it possible to significantly expand information about animals and plants. The rapid accumulation of scientific knowledge about living organisms led to the division of biology into separate sciences.
In the XVI-XVII centuries. Botany and zoology began to develop rapidly.
The invention of the microscope (early 17th century) made it possible to study the microscopic structure of plants and animals. Microscopically small living organisms - bacteria and protozoa - were discovered, invisible to the naked eye.
Carl Linnaeus made a great contribution to the development of biology, proposing a system of classification of animals and plants,
Karl Maksimovich Baer (1792-1876) in his works formulated the basic principles of the theory of homologous organs and the law of germinal similarity, which laid the scientific foundations of embryology.
In 1808, in his work “Philosophy of Zoology,” Jean Baptiste Lamarck raised the question of the causes and mechanisms of evolutionary transformations and outlined the first theory of evolution.
The cell theory played a huge role in the development of biology, which scientifically confirmed the unity of the living world and served as one of the prerequisites for the emergence of Charles Darwin's theory of evolution. The authors of the cell theory are considered to be the zoologist Theodor Ivann (1818-1882) and the botanist Matthias Jakob Schleiden (1804-1881).
Based on numerous observations, Charles Darwin published his main work in 1859, “On the Origin of Species by Natural Selection or the Preservation of Favored Breeds in the Struggle for Life,” in which he formulated the basic principles of the theory of evolution, proposed mechanisms of evolution and ways of evolutionary transformations of organisms.
In the 19th century Thanks to the work of Louis Pasteur (1822-1895), Robert Koch (1843-1910), and Ilya Ilyich Mechnikov, microbiology took shape as an independent science.
The 20th century began with the rediscovery of Gregor Mendel's laws, which marked the beginning of the development of genetics as a science.
In the 40-50s of the XX century. in biology, ideas and methods of physics, chemistry, mathematics, cybernetics and other sciences began to be widely used, and microorganisms were used as objects of research. As a result, biophysics, biochemistry, molecular biology, radiation biology, bionics, etc. arose and began to rapidly develop as independent sciences. Research in space contributed to the emergence and development of space biology.
In the 20th century a direction of applied research appeared - biotechnology. This direction will undoubtedly develop rapidly in the 21st century. You will learn more about this direction of development of biology when studying the chapter “Fundamentals of selection and biotechnology”.
Currently, biological knowledge is used in all spheres of human activity: in industry and agriculture, medicine and energy.
Ecological research is extremely important. We finally began to realize that the fragile balance that exists on our small planet can be easily destroyed. Humanity is faced with a tremendous task - preserving the biosphere in order to maintain the conditions of existence and development of civilization. It is impossible to solve it without biological knowledge and special research. Thus, at present, biology has become a real productive force and a rational scientific basis for the relationship between man and nature.
Classical biology. Evolutionary biology. Physico-chemical biology.
1. What directions in the development of biology can you highlight?
2. Which great scientists of antiquity made a significant contribution to the development of biological knowledge?
3. Why in the Middle Ages could one speak only conditionally about biology as a science?
4. Why is modern biology considered a complex science?
5. What is the role of biology in modern society?
6. Prepare a message on one of the following topics:
7. The role of biology in modern society.
8. The role of biology in space research.
9. The role of biological research in modern medicine.
10. The role of outstanding biologists - our compatriots in the development of world biology.
How much scientists' views on the diversity of living things have changed can be demonstrated by the example of the division of living organisms into kingdoms. Back in the 40s of the 20th century, all living organisms were divided into two kingdoms: Plants and Animals. The plant kingdom also included bacteria and fungi. Later, a more detailed study of organisms led to the identification of four kingdoms: Prokaryotes (Bacteria), Fungi, Plants and Animals. This system is given in school biology.
In 1959, it was proposed to divide the world of living organisms into five kingdoms: Prokaryotes, Protists (Protozoa), Fungi, Plants and Animals.
This system is often cited in biological (especially translated) literature.
Other systems have been developed and continue to be developed, including 20 or more kingdoms. For example, it has been proposed to distinguish three superkingdoms: Prokaryotes, Archaea (Archebacteria) and Eukaryotes. Each superkingdom includes several kingdoms.
Kamensky A. A. Biology 10-11 grade
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