What biological sciences study plants. Biological sciences and their definitions

Biology is the science of life. At present, it is a complex of sciences about wildlife. The object of study of biology are living organisms - plants and animals. and study the diversity of species, the structure of the body and the functions of organs, development, distribution, their communities, evolution.

The first information about living organisms began to accumulate even primitive man. Living organisms brought him food, material for clothing and housing. Already at that time, a person could not do without knowledge about the properties of plants, their places of growth, the timing of the ripening of fruits and seeds, about the habitats and habits of the animals he hunted, predators and poisonous animals that could threaten his life.

So gradually accumulated information about living organisms. The domestication of animals and the beginning of the cultivation of plants required deeper knowledge about living organisms.

First founders

Significant factual material about living organisms was collected by the great physician of Greece - Hippocrates (460-377 BC). He collected information about the structure of animals and humans, gave a description of the bones, muscles, tendons, brain and spinal cord.

The first major work zoology belongs to the Greek naturalist Aristotle (384-322 BC). He described over 500 species of animals. Aristotle was interested in the structure and lifestyle of animals, he laid the foundations of zoology.

The first work on the systematization of knowledge about plants ( botany) was made by Theophrastus (372-287 BC).

Ancient science owes the expansion of knowledge about the structure of the human body (anatomy) to the doctor Galen (130-200 BC), who performed autopsies on monkeys and pigs. His works influenced natural science and medicine for several centuries.

In the Middle Ages, under the yoke of the church, science developed very slowly. An important milestone in the development of science was the Renaissance, which began in the XV century. Already in the XVIII century. Botany, zoology, human anatomy, and physiology developed as independent sciences.

Milestones in the study of the organic world

Gradually, information was accumulated about the diversity of species, the structure of the body of animals and humans, individual development, and the functions of plant and animal organs. Throughout the centuries-old history of biology, the largest milestones in the study of the organic world can be called:

• Introduction of the principles of systematics proposed by K. Linnaeus;
• the invention of the microscope;
• T. Schwann's creation of the cell theory;
• approval of the evolutionary teachings of Ch. Darwin;
• G. Mendel's discovery of the main patterns of heredity;
• the use of an electron microscope for biological research;
• deciphering the genetic code;
• creation of the doctrine of the biosphere.

To date, about 1,500,000 animal species and about 500,000 plant species are known to science. The study of the diversity of plants and animals, the features of their structure and vital activity is of great importance. Biological sciences are the basis for the development of crop production, animal husbandry, medicine, bionics, and biotechnology.

One of the oldest biological sciences is human anatomy and physiology, which make up the theoretical foundation of medicine. Each person should have an idea about the structure and functions of his body, so that, if necessary, be able to provide first aid, consciously protect his health and follow hygiene rules.

For centuries, botany, zoology, anatomy, physiology were developed by scientists as independent, isolated sciences. Only in the XIX century. regularities common to all living beings were discovered. This is how the sciences that study the general patterns of life arose. These include:

• Cytology is the science of the cell;
• genetics - the science of variability and heredity;
• ecology - the science of the relationship of an organism with the environment and in communities of organisms;
• Darwinism - the science of the evolution of the organic world and others.

In the curriculum, they form the subject of general biology.

Biology(from the Greek bios - life, logos - word, science) is a complex of sciences about wildlife.

The subject of biology is all manifestations of life: the structure and functions of living beings, their diversity, origin and development, as well as interaction with the environment. The main task of biology as a science is to interpret all the phenomena of living nature on a scientific basis, while taking into account that the whole organism has properties that are fundamentally different from its components.

Biology studies all aspects of life, in particular, the structure, functioning, growth, origin, evolution and distribution of living organisms on Earth, classifies and describes living beings, the origin of their species, interaction with each other and with the environment.

At the heart of modern biology are 5 fundamental principles:

1. cell theory
2. evolution
3. genetics
4. homeostasis
5. energy

Biological Sciences

Currently, biology includes a number of sciences that can be systematized according to the following criteria: subject and predominant methods research and study the level of organization of wildlife.

By subject of researchI biological sciences are divided into bacteriology, botany, virology, zoology, mycology.

Botany is a biological science that comprehensively studies plants and the vegetation cover of the Earth.

Zoology - a branch of biology, the science of diversity, structure, life, distribution and relationship of animals with the environment, their origin and development.

Bacteriology - biological science that studies the structure and vital activity of bacteria, as well as their role in nature.

Virology is the biological science that studies viruses.

main object mycology are mushrooms, their structure and features of vital activity.

Lichenology - biological science that studies lichens.

Bacteriology, virology and some aspects of mycology are often considered within microbiology - section of biology, the science of microorganisms (bacteria, viruses and microscopic fungi).

Systematics, or taxonomy, - biological science that describes and classifies into groups all living and extinct creatures.

In turn, each of the listed biological sciences is subdivided into biochemistry, morphology, anatomy, physiology, embryology, genetics and taxonomy (of plants, animals or microorganisms). Biochemistry - this is the science of the chemical composition of living matter, chemical processes occurring in living organisms and underlying their vital activity.

Morphology - biological science that studies the shape and structure of organisms, as well as the patterns of their development. In a broad sense, it includes cytology, anatomy, histology and embryology. Distinguish the morphology of animals and plants.

Anatomy - This is a branch of biology (more precisely, morphology), a science that studies the internal structure and shape of individual organs, systems and the body as a whole. Plant anatomy is considered as part of botany, animal anatomy is considered as part of zoology, and human anatomy is a separate science.

Physiology - biological science that studies the processes of vital activity of plant and animal organisms, their individual systems, organs, tissues and cells. There are physiology of plants, animals and humans.

Embryology(developmental biology)- a branch of biology, the science of the individual development of the organism, including the development of the embryo.

object genetics are patterns of heredity and variability. Currently, it is one of the most dynamically developing biological sciences.

By the studied level of organization of living nature they distinguish molecular biology, cytology, histology, organology, biology of organisms and supraorganismal systems.

Molecular biology is one of the youngest sections of biology, a science that studies, in particular, the organization of hereditary information and protein biosynthesis.

Cytology, or cell Biology,- biological science, the object of study of which are the cells of both unicellular and multicellular organisms.

Histology - biological science, a section of morphology, the object of which is the structure of tissues of plants and animals.

To the sphere organology include the morphology, anatomy and physiology of various organs and their systems. Biology of organisms includes all sciences that deal with living organisms, for example, ethology the science of the behavior of organisms.

The biology of supraorganismal systems is subdivided into biogeography and ecology. The distribution of living organisms studies biogeography, whereas ecology - organization and functioning of supraorganismal systems at various levels: populations, biocenoses (communities), biogeocenoses (ecosystems) and the biosphere.

By prevailing research methods one can distinguish descriptive (for example, morphology), experimental (for example, physiology) and theoretical biology. Revealing and explaining the regularities of the structure, functioning and development of living nature at various levels of its organization is a task general biology. It includes biochemistry, molecular biology, cytology, embryology, genetics, ecology, evolutionary science and anthropology. evolutionary doctrine studies the causes, driving forces, mechanisms and general patterns of evolution of living organisms. One of its sections is paleontology- science, the subject of which are the fossil remains of living organisms. Anthropology- a section of general biology, the science of the origin and development of man as a biological species, as well as the diversity of populations of modern man and the patterns of their interaction. Applied aspects of biology are assigned to the field of biotechnology, breeding and other rapidly developing sciences. Biotechnology called the biological science that studies the use of living organisms and biological processes in production. It is widely used in food (baking, cheese-making, brewing, etc.) and pharmaceutical industries (obtaining antibiotics, vitamins), for water purification, etc. Selection- the science of methods for creating breeds of domestic animals, varieties of cultivated plants and strains of microorganisms with the properties necessary for a person. Selection is also understood as the process of changing living organisms, carried out by man for his needs.

The progress of biology is closely related to the success of other natural and exact sciences, such as physics, chemistry, mathematics, computer science, etc. For example, microscopy, ultrasound (ultrasound), tomography and other processes occurring in living systems would be impossible without the use of chemical and physical methods. The use of mathematical methods allows, on the one hand, to identify the presence of a regular connection between objects or phenomena, to confirm the reliability of the results obtained, and on the other hand, to model a phenomenon or process. Recently, computer methods, such as modeling, have become increasingly important in biology. At the intersection of biology and other sciences, a number of new sciences have arisen, such as biophysics, biochemistry, bionics, etc.

The role of biology in the formation of the modern natural-science picture of the world

At the stage of formation, biology did not yet exist separately from other natural sciences and was limited only to observation, study, description and classification of representatives of the animal and plant world, that is, it was a descriptive science. However, this did not prevent the ancient naturalists Hippocrates (c. 460-377 BC), Aristotle (384-322 BC) and Theophrastus (real name Tirtham, 372-287 BC). e.) to make a significant contribution to the development of ideas about the structure of the human and animal body, as well as the biological diversity of animals and plants, thereby laying the foundations of human anatomy and physiology, zoology and botany. The deepening of knowledge about living nature and the systematization of previously accumulated facts that took place in the 16th-18th centuries culminated in the introduction of binary nomenclature and the creation of a coherent taxonomy of plants (C. Linnaeus) and animals (J.-B. Lamarck). The description of a significant number of species with similar morphological features, as well as paleontological finds, became prerequisites for the development of ideas about the origin of species and the paths of the historical development of the organic world. Thus, the experiments of F. Redi, L. Spallanzani and L. Pasteur in the 17th-19th centuries refuted the hypothesis of spontaneous spontaneous generation put forward by Aristotle and existed in the Middle Ages, and the theory of biochemical evolution by A.I. Oparin and J. Haldane, brilliantly confirmed by S. Miller and G. Urey, made it possible to answer the question of the origin of all living things. If the very process of the emergence of the living from non-living components and its evolution in themselves no longer raise doubts, then the mechanisms, ways and directions of the historical development of the organic world are still not fully elucidated, since none of the two main competing theories of evolution (the synthetic theory evolution, created on the basis of the theory of C. Darwin, and the theory of J.-B. Lamarck) still cannot provide exhaustive evidence. The use of microscopy and other methods of related sciences, due to progress in the field of other natural sciences, as well as the introduction of experimental practice, allowed the German scientists T. Schwann and M. Schleiden to formulate a cell theory back in the 19th century, later supplemented by R. Virchow and K. Baer. It became the most important generalization in biology, which formed the cornerstone of modern ideas about the unity of the organic world. The discovery of the patterns of transmission of hereditary information by the Czech monk G. Mendel served as an impetus for the further rapid development of biology in the 20th-21st centuries and led not only to the discovery of the universal carrier of heredity - DNA, but also the genetic code, as well as fundamental mechanisms for controlling, reading and variability of hereditary information . The development of ideas about the environment has led to the emergence of such a science as ecology, and wording the doctrine of the biosphere as a complex multi-component planetary system of interconnected huge biological complexes, as well as chemical and geological processes occurring on Earth (V.I. Vernadsky), which ultimately allows at least to a small extent to reduce the negative consequences of human economic activity. Thus, biology has played an important role in the formation of the modern natural-science picture of the world.

Methods for studying living objects

Like any other science, biology has its own arsenal of methods. In addition to the scientific method of cognition, which is used in other branches, such methods as historical, comparative descriptive, etc. are widely used in biology.

scientific method knowledge includes observation, formulation of hypotheses, experiment, modeling, analysis of results and derivation of general patterns.

Observation- this is a purposeful perception of objects and phenomena with the help of sensory organs or instruments, due to the task of activity. The main condition for scientific observation is its objectivity, i.e. the possibility of verifying the data obtained by repeated observation or the use of other research methods, such as experiment. The facts obtained as a result of observation are called data. They can be like quality(describing smell, taste, color, shape, etc.), and quantitative, moreover, quantitative data are more accurate than qualitative ones.

On the basis of observational data, a hypothesis is formulated - a hypothetical judgment about the regular connection of phenomena. The hypothesis is tested in a series of experiments.

experiment called scientifically staged experience, the observation of the phenomenon under study under controlled conditions, allowing to identify the characteristics of this object or phenomenon. The highest form of experiment is modeling - the study of any phenomena, processes or systems of objects by building and studying their models. In essence, this is one of the main categories of the theory of knowledge: any method of scientific research, both theoretical and experimental, is based on the idea of ​​modeling. The results of the experiment and simulation are subjected to a thorough analysis.

Analysis called the method of scientific research by decomposing an object into its component parts or mental dismemberment of an object by logical abstraction. Analysis is inextricably linked with synthesis.

Synthesis- this is a method of studying the subject in its integrity, in the unity and interconnection of its parts. As a result of analysis and synthesis, the most successful research hypothesis becomes a working hypothesis, and if it is able to resist attempts to refute it and still successfully predicts previously unexplained facts and relationships, then it can become theory.

Under theory understand such a form of scientific knowledge that gives a holistic view of the patterns and essential connections of reality. The general direction of scientific research is to achieve higher levels of predictability. If no facts can change a theory, and the deviations from it that occur are regular and predictable, then it can be elevated to the rank law- a necessary, essential, stable, recurring relationship between phenomena in nature. As the body of knowledge increases and research methods improve, hypotheses and even well-established theories can be challenged, modified, and even rejected, since scientific knowledge itself is dynamic in nature and is constantly subjected to critical rethinking.

The historical method reveals the patterns of the appearance and development of organisms, the formation of their structure and function. In a number of cases, with the help of this method, hypotheses and theories that were previously considered false acquire new life. So, for example, happened with Darwin's assumptions about the nature of signaling through the plant in response to environmental influences. The comparative-descriptive method provides for an anatomical and morphological analysis of the objects of study. It underlies the classification of organisms, identifying patterns of emergence and development of various forms of life.

Monitoring is a system of measures for monitoring, evaluating and predicting changes in the state of the object under study, in particular the biosphere. Conducting observations and experiments often requires the use of special equipment, such as microscopes, centrifuges, spectrophotometers, etc. Microscopy is widely used in zoology, botany, human anatomy, histology, cytology, genetics, embryology, paleontology, ecology and other branches of biology. It allows you to study the fine structure of objects using light, electron, X-ray and other types of microscopes.

The light microscope consists of optical and mechanical parts. The optical parts are involved in the construction of the image, and the mechanical ones serve for the convenience of using the optical parts. The total magnification of a microscope is determined by the formula: objective magnification x eyepiece magnification = microscope magnification.

For example, if the objective magnifies an object by 8 times and the eyepiece magnifies by 7 times, then the total magnification of the microscope is 56.

Differential centrifugation, or fractionation, makes it possible to separate particles according to their size and density under the action of centrifugal force, which is actively used in studying the structure of biological molecules and cells.

The main levels of organization of wildlife

1. Molecular genetic. The most important tasks of biology at this stage is the study of the mechanisms of transmission of gene information, heredity and variability.
2. Cellular level. The elementary unit of the cellular level of organization is the cell, and the elementary phenomenon is the reaction of cellular metabolism.
3. tissue level. This level is represented by tissues that combine cells of a certain structure, size, location and similar functions. Tissues arose in the course of historical development along with multicellularity. In multicellular organisms, they are formed in the process of ontogeny as a result of cell differentiation.
4. Organ level. The organ level is represented by the organs of organisms. In protozoa, digestion, respiration, circulation of substances, excretion, movement and reproduction are carried out by various organelles. More advanced organisms have organ systems. In plants and animals, organs are formed due to a different number of tissues.
5. Organism level. The elementary unit of this level is an individual in its individual development, or ontogenesis, therefore the organismal level is also called ontogenetic. An elementary phenomenon of this level is the changes in the organism in its individual development.
6. Population-species level. A population is a collection of individuals of the same species that freely interbreed and live apart from other similar groups of individuals. In populations, there is a free exchange of hereditary information and its transmission to descendants. The population is the elementary unit of the population-species level, and the elementary phenomenon in this case are evolutionary transformations, such as mutations and natural selection.
7. Biogeocenotic level. Biogeocenosis is a historically established community of populations of different species, interconnected with each other and the environment through the metabolism and energy. Biogeocenoses are elementary systems in which the material-energy cycle is carried out, due to the vital activity of organisms. Biogeocenoses themselves are elementary units of a given level, while elementary phenomena are energy flows and the circulation of substances in them. Biogeocenoses make up the biosphere and determine all the processes occurring in it.
8. biospheric level. The biosphere is the shell of the Earth inhabited by living organisms and transformed by them. The biosphere is the highest level of organization of life on the planet. This shell covers the lower part of the atmosphere, the hydrosphere and the upper layer of the lithosphere. The biosphere, like all other biological systems, is dynamic and actively transformed by living beings. It itself is an elementary unit of the biospheric level, and as an elementary phenomenon, they consider the processes of circulation of substances and energy that occur with the participation of living organisms.

As mentioned above, each of the levels of organization of living matter contributes to a single evolutionary process: the cell not only reproduces the inherent hereditary information, but also changes it, which leads to the emergence of new combinations of signs and properties of the organism, which in turn are subjected to the action of natural selection at the population-species level, etc.

Importance of biology for medicine:

Genetic research has made it possible to develop methods for early diagnosis, treatment and prevention of human hereditary diseases;

The selection of microorganisms makes it possible to obtain enzymes, vitamins, hormones necessary for the treatment of a number of diseases;

Genetic engineering allows the production of biologically active compounds and drugs;

Definition of the concept of "life" at the present stage of science. Fundamental properties of living things: It is quite difficult to give a complete and unambiguous definition of the concept of life, given the huge variety of its manifestations. In most definitions of the concept of life, which were given by many scientists and thinkers over the centuries, the leading qualities that distinguish the living from the non-living were taken into account. For example, Aristotle said that life is "nutrition, growth and decrepitude" of the body; A. L. Lavoisier defined life as a “chemical function”; G. R. Treviranus believed that life is "a stable uniformity of processes with a difference in external influences." It is clear that such definitions could not satisfy scientists, since they did not reflect (and could not reflect) all the properties of living matter. In addition, observations indicate that the properties of the living are not exceptional and unique, as it seemed before, they are separately found among non-living objects. AI Oparin defined life as "a special, very complex form of the movement of matter." This definition reflects the qualitative originality of life, which cannot be reduced to simple chemical or physical laws. However, even in this case, the definition is of a general nature and does not reveal the specific peculiarity of this movement.

F. Engels in "Dialectics of Nature" wrote: "Life is a mode of existence of protein bodies, the essential point of which is the exchange of matter and energy with the environment."

For practical application, those definitions are useful, which contain the basic properties that are necessarily inherent in all living forms. Here is one of them: life is a macromolecular open system, which is characterized by a hierarchical organization, the ability to self-reproduce, self-preservation and self-regulation, metabolism, a finely regulated flow of energy. According to this definition, life is a core of order spreading in a less ordered universe.

Life exists in the form of open systems. This means that any living form is not closed only on itself, but constantly exchanges matter, energy and information with the environment.

2. Evolutionary-conditioned levels of life organization: There are such levels of organization of living matter - levels of biological organization: molecular, cellular, tissue, organ, organism, population-species and ecosystem.

Molecular level of organization- this is the level of functioning of biological macromolecules - biopolymers: nucleic acids, proteins, polysaccharides, lipids, steroids. From this level, the most important life processes begin: metabolism, energy conversion, transmission of hereditary information. This level is studied: biochemistry, molecular genetics, molecular biology, genetics, biophysics.

Cellular level- this is the level of cells (cells of bacteria, cyanobacteria, unicellular animals and algae, unicellular fungi, cells of multicellular organisms). A cell is a structural unit of the living, a functional unit, a unit of development. This level is studied by cytology, cytochemistry, cytogenetics, microbiology.

Tissue level of organization- This is the level at which the structure and functioning of tissues is studied. This level is studied by histology and histochemistry.

Organ level of organization- This is the level of organs of multicellular organisms. Anatomy, physiology, embryology study this level.

Organismal level of organization- this is the level of unicellular, colonial and multicellular organisms. The specificity of the organismic level is that at this level the decoding and implementation of genetic information takes place, the formation of features inherent in individuals of a given species. This level is studied by morphology (anatomy and embryology), physiology, genetics, paleontology.

Population-species level is the level of aggregates of individuals - populations and species. This level is studied by systematics, taxonomy, ecology, biogeography, and population genetics. At this level, genetic and ecological features of populations, elementary evolutionary factors and their influence on the gene pool (microevolution), the problem of species conservation are studied.

Biogeocenotic level of life organization - represented by a variety of natural and cultural biogeocenoses in all living environments . Components- Populations of different species; environmental factors ; Food webs, matter and energy flows ; Basic processes; Biochemical cycling and energy flow that sustain life ; Moving equilibrium between living organisms and the abiotic environment (homeostasis) ; Providing living organisms with living conditions and resources (food and shelter). Sciences leading research at this level: Biogeography, Biogeocenology Ecology

Biospheric level of life organization

It is represented by the highest, global form of organization of biosystems - the biosphere. Components - Biogeocenoses; Anthropogenic impact; Basic processes; Active interaction of living and non-living matter of the planet; Biological global circulation of matter and energy;

Active biogeochemical participation of man in all processes of the biosphere, his economic and ethnocultural activities

Sciences leading research at this level: Ecology; Global ecology; Space ecology; Social ecology.

Biological sciences and aspects studied by them. Anatomy is the science of the internal structure of the body. Genetics is about heredity and variation. Embryology is the science of the embryonic development of an organism. Histology is the science of tissue structure. Cytology is the science of the structure of cell activity. Morphology is the science of the external structure of an organism. Physiology is a science that studies the processes of life. Zoology is the science of animals. Botany is the science of plants. Microbiology is the science of bacteria and viruses.

Biology grade 10

"Methods of reproduction" - Reproduction by spores. Reproduction by division. The formation of germ cells. Types of asexual reproduction. Sporulation. Sexual reproduction. Individuals identical to the original organism. Asexual reproduction. vegetative reproduction. Reproduction. The ability to combine genetic material. The disappearance of sexual reproduction.

"Theories of the origin of life" - My best lesson. Scheme of the transition of chemical evolution. Nebula. The problem of nature. origin theories. Rules of judicial ethics. History of representations. Stages of the emergence of the solar system. Lesson structure. The history of ideas about the origin of life. Group work in the classroom. Judges work. Hypotheses for the origin of life. Matter. Lesson stage. modern hypotheses. Debate. Game regulations. Additional question.

"Inorganic compounds of the cell" - Chemical elements of the cell. The chemical composition of the cell. Functions of water. Polarity of living cell membranes. Included in water. Protein component. Composition of blood plasma. Exercise. Chemical substances. Note the properties of water. Highlight characteristic properties. Water properties. Macronutrients. Substances. Dipole structure.

"Problems of the origin of life on Earth" - The emergence of multicellular organisms. Conditions for the emergence of primitive living beings. The history of carbon. coacervate droplets. The emergence of primary organisms. Works by L. Pasteur. Theories of the origin of life. Development of life. History of ideas about the origin of life. Origin of life on Earth. From carbon to proteins. Representations of ancient and medieval philosophers. Age of the Earth. Possibility of formation of complex organic compounds.

"Population dynamics" - A unicellular amoeba divides into two cells every three hours. Rare species. Dictionary. survival curves. Mathematical and computer modeling. Malthus' law. Population development models. Ecological strategy. The predator-prey model. Anthropogenic impact on growth types. Types of population growth. Graphs of changes in the number of populations. Lesson plan. R-strategists. population density. Which species have stable population dynamics.

"Viruses in the body" - Due to the high mutability of viruses, the treatment of viral diseases is quite difficult. Viral diseases. Structure and classification of viruses. Viruses are the causative agents of many dangerous diseases of humans, animals and plants. Viruses have heredity. The first mention of smallpox in Russia dates back to the 4th century. Attempts to use viruses for the benefit of humanity are quite few. Like other organisms, viruses are capable of replication.

Classifies and describes living beings, the origin of their species, interaction with each other and with the environment.

As an independent science, biology emerged from the natural sciences in the 19th century, when scientists discovered that all living organisms have some common properties and features that, in aggregate, are not characteristic of inanimate nature. The term "biology" was introduced independently by several authors: Friedrich Burdach in 1800, Gottfried Reinhold Treviranus in 1802 and Jean-Baptiste Lamarck in 1802.

Biological picture of the world

At present, biology is a standard subject in secondary and higher educational institutions around the world. Over a million articles and books in biology, medicine, biomedicine, and bioengineering are published each year.

• Cell theory - the doctrine of everything related to cells. All living organisms consist of at least one cell - the main structural and functional unit of organisms. The basic mechanisms and chemistry of all cells in all terrestrial organisms are similar; cells come only from pre-existing cells that multiply by cell division. The cell theory describes the structure of cells, their division, interaction with the external environment, the composition of the internal environment and the cell membrane, the mechanism of action of individual parts of the cell and their interaction with each other.
• Evolution. Through natural selection and genetic drift, the hereditary traits of a population change from generation to generation.
• The Theory of the Gene. The traits of living organisms are passed down from generation to generation along with the genes that are encoded in the DNA. Information about the structure of living things or the genotype is used by cells to create the phenotype, the observable physical or biochemical characteristics of the organism. Although a phenotype, expressed through gene expression, can prepare an organism for life in its environment, information about the environment is not passed back into the genes. Genes can only change in response to environmental influences through the evolutionary process.
• Homeostasis. Physiological processes that allow an organism to maintain a constant internal environment regardless of changes in the external environment.
• Energy. An attribute of any living organism, essential for its state.

cell theory

Evolution

The central organizing concept in biology is that life changes and evolves over time through evolution, and that all known forms of life on Earth share a common origin. This led to the similarity of the basic units and processes of life mentioned above. The concept of evolution was introduced into the scientific lexicon by Jean-Baptiste Lamarck in 1809. Charles Darwin established fifty years later that natural selection is its driving force, just as artificial selection is consciously applied by man to create new animal breeds and plant varieties. Later, in the synthetic theory of evolution, genetic drift was postulated as an additional mechanism for evolutionary change.

gene theory

The form and function of biological objects are reproduced from generation to generation by genes, which are the elementary units of heredity. Physiological adaptation to the environment cannot be encoded in genes and be inherited in offspring (see Lamarckism). It is noteworthy that all existing forms of terrestrial life, including bacteria, plants, animals and fungi, have the same basic mechanisms for DNA copying and protein synthesis. For example, bacteria injected with human DNA are capable of synthesizing human proteins.

The totality of the genes of an organism or cell is called the genotype. Genes are stored on one or more chromosomes. A chromosome is a long chain of DNA that can carry many genes. If a gene is active, then its DNA sequence is copied into RNA sequences via transcription. The ribosome can then use the RNA to synthesize the protein sequence corresponding to the RNA code in a process called translation. Proteins can perform a catalytic (enzymatic) function, transport, receptor, protective, structural, motor functions.

homeostasis

Homeostasis is the ability of open systems to regulate their internal environment in such a way as to maintain its constancy through a variety of corrective actions directed by regulatory mechanisms. All living things, both multicellular and unicellular, are capable of maintaining homeostasis. At the cellular level, for example, a constant acidity of the internal environment () is maintained. Warm-blooded animals maintain a constant body temperature at the body level. In association with the term ecosystem, homeostasis is understood, in particular, as the maintenance by plants and algae of a constant concentration of atmospheric oxygen and carbon dioxide on Earth.

Energy

The survival of any organism depends on a constant supply of energy. Energy is drawn from substances that serve as food, and through special chemical reactions is used to build and maintain the structure and functioning of cells. In this process, food molecules are used both to extract energy and to synthesize the body's own biological molecules.

The primary source of energy for the vast majority of terrestrial beings is light energy, mainly solar, however, some bacteria and archaea obtain energy through chemosynthesis. Light energy through photosynthesis is converted by plants into chemical (organic molecules) in the presence of water and certain minerals. Part of the energy received is spent on increasing biomass and maintaining life, the other part is lost in the form of heat and waste products. The general mechanisms for converting chemical energy into life-sustaining energy are called respiration and metabolism.

Levels of life organization

Living organisms are highly organized structures, therefore, in biology, a number of levels of organization are distinguished. In various sources, some levels are omitted or combined with each other. Below are the main levels of organization of wildlife separately from each other.

• Molecular - the level of interaction of molecules that make up the cell and determine all its processes.
• Cellular - the level at which cells are considered as elementary units of the structure of the living.
• Tissue - the level of sets of cells similar in structure and function that form tissues.
• Organ - the level of individual organs that have their own structure (association of tissue types) and location in the body.
• Organismic - the level of an individual organism.
• Population-species level - the level of a population made up of a set of individuals of the same species.
• Biogeocenotic - the level of interaction of species among themselves and with various environmental factors.
• The biospheric level is the totality of all biogeocenoses, including and causing all the phenomena of life on Earth.

Biological Sciences

Most biological sciences are disciplines with a narrower focus. Traditionally, they are grouped according to the types of organisms studied:

• botany is the study of plants, algae, fungi and mushroom-like organisms,
• zoology - animals and protists,
• microbiology - microorganisms and viruses.

• biochemistry studies the chemical basis of life,
• biophysics studies the physical foundations of life,
• molecular biology - complex interactions between biological molecules,
• cell biology and cytology - the basic building blocks of multicellular organisms, cells,
• histology and anatomy - the structure of tissues and the body from individual organs and tissues,
• physiology - the physical and chemical functions of organs and tissues,
• ethology - the behavior of living beings,
• ecology - the interdependence of various organisms and their environment,
• genetics - patterns of heredity and variability,
• developmental biology - the development of an organism in ontogeny,
• paleobiology and evolutionary biology - the origin and historical development of wildlife.

On the borders with related sciences, there are: biomedicine, biophysics (the study of living objects by physical methods), biometrics, etc. In connection with the practical needs of man, such areas as space biology, sociobiology, labor physiology, bionics.

Biological disciplines

History of biology

Although the concept of biology as a distinct natural science originated in the 19th century, the biological disciplines originated earlier in medicine and natural history. Usually their tradition is traced from such ancient scientists as Aristotle and Galen through the Arab physicians al-Jahiz, ibn-Sina, ibn-Zuhra and ibn-al-Nafiz. During the Renaissance, biological thought in Europe was revolutionized by the invention of printing and the spread of printed works, the interest in experimental research, and the discovery of many new animal and plant species during the Age of Discovery. At this time, the outstanding minds Andrei Vesalius and William Harvey worked, who laid the foundations of modern anatomy and physiology. Somewhat later, Linnaeus and Buffon did a great job of classifying the forms of living and fossil creatures. Microscopy opened the previously unknown world of microorganisms to observation, laying the foundation for the development of cell theory. The development of natural science, due in part to the emergence of mechanistic philosophy, contributed to the development of natural history.

By the early 19th century, some of the modern biological disciplines, such as botany and zoology, had reached a professional level. Lavoisier and other chemists and physicists began to converge ideas about animate and inanimate nature. Naturalists such as Alexander Humboldt have explored the interaction of organisms with their environment and its dependence on geography, laying the foundations for biogeography, ecology and ethology. In the 19th century, the development of the doctrine of evolution gradually led to an understanding of the role of extinction and the variability of species, and the cellular theory showed in a new light the fundamentals of the structure of living matter. Combined with data from embryology and paleontology, these advances allowed Charles Darwin to create a holistic theory of evolution based on natural selection. By the end of the 19th century, the ideas of spontaneous generation finally gave way to the theory of an infectious agent as a causative agent of diseases. But the mechanism of inheritance of parental traits was still a mystery.

Popularization of biology

see also