Terms on biology by topics. Basic biological terms (Glossary). Organelles are divided according to the number of membranes

Completing Missing Information - Complete the Sentence (Advanced)

You can repeat the material for solving tasks in the General Biology section

1. The branch of science and production that develops ways to use biological objects in modern production is

Answer: biotechnology.

2. The science that studies the shape and structure of individual organs, their systems and the whole organism as a whole is

Answer: anatomy.

3. Science that studies the origin and evolution of man as a biosocial species, education human races, - this is

Answer: anthropology.

4. "Record" hereditary information happens at... the level of the organization.

Answer: molecular.

5. Seasonal changes in wildlife are studied by science

Answer: phenology.

6. Microbiology as an independent science took shape thanks to the work

Answer: L. Pasteur (Pasteur)

7. For the first time, a classification system for animals and plants was proposed

Answer: K. Linnaeus (Linnaeus)

8. The founder of the first evolutionary theory was

Answer: J.-B. Lamarck (Lamarck)

9. The founder of medicine is considered

Answer: Hippocrates (Hippocrates).

10. The main provisions of the theory of homologous organs and the law of germinal similarity were formulated by

Answer: K. Baer (Baer).

11. In science, hypotheses are tested using ... a method.

Answer: experimental.

12. Founder experimental method in biology consider

Answer: I. P. Pavlova (Pavlov).

13. A set of techniques and operations used in building a system of reliable knowledge is ... a method.

Answer: scientific.

14. Supreme form experiment consider

Answer: modeling.

15. The ability of organisms to reproduce themselves is

Answer: reproduction.

16. The branch of biology that studies the tissues of multicellular organisms is

Answer: histology.

17. The law of biogenic migration of atms formulated

18. The law of linked inheritance of traits discovered

Answer: T. Morgan (Morgan).

19. The law of irreversibility of evolution formulated

Answer: L. Dollo (Dollo).

20. The law of correlation of parts of the body, or the ratio of organs formulated

Answer: J. Cuvier (Cuvier).

21. The law of change of phases (directions) of evolution formulated

Answer: A. N. Severtsov (Severtsov).

22. The doctrine of the biosphere was developed

Answer: V. I. Vernadsky (Vernadsky).

23. The law of physical and chemical unity of living matter formulated

Answer: V. I. Vernadsky (Vernadsky).

24. The founder of evolutionary paleontology was

Answer: V. O. Kovalevsky (Kovalevsky).

25. Science that studies the structure and life of the cell

Answer: cytology

26. The science that studies the behavior of animals is

Answer: Ethology.

27. The science involved in the planning of quantitative biological experiments and the processing of results using the methods of mathematical statistics is

Answer: biometrics.

28. Science being studied general properties and manifestations of life cellular level, - this is

Answer: cytology

29. The science that studies the historical development of living nature is

Answer: evolution.

30. The science that studies algae is

Answer: algology.

31. The science that studies insects is

Answer: entomology.

32. The inheritance of hemophilia in humans has been established using ... method.

Answer: genealogical.

33. When studying cells with the help of modern devices, they use ... method.

Answer: instrumental.

34. The influence of living and working conditions on health studies

Answer: hygiene.

35. Biosynthetic processes organic compounds occur at... the level of organization of living matter.

Answer: molecular.

36. Oak grove is an example... of the level of organization of living matter.

Answer: biogeocenotic.

37. Storage and transmission of hereditary information occurs at ... the level of organization of living matter.

Answer: molecular.

38. Study natural phenomena under given conditions allows the method

Answer: experiment.

39. The internal structure of mitochondria allows you to study ... a microscope.

Answer: electronic.

40. Changes occurring in the somatic cell during mitosis, allows you to study the method

Answer: microscopy.

41. To identify the nature and type of inheritance of traits from generation to generation based on the study of a person's pedigree allows ... the method of genetics.

Answer: genealogical.

42. Transcription and translation occurs at ... the level of organization of the living.

Answer: molecular.

43. In taxonomy, the method is used

Answer: classifications.

44. A sign of the living, the essence of which lies in the ability of organisms to reproduce their own kind, is

Answer: reproduction.

45. Sign of the living, the essence of which is the ability of living systems to maintain the relative constancy of their internal environment, - this is

Answer: homeostasis.

46. One of the most important principles for the organization of biological systems is their

Answer: openness.

47. The structure of plastids is studied using the method ... microscopy.

Answer: electronic.

48. Ecology does NOT study ... the level of organization of life.

Answer: cellular.

49. The ability of biosystems to maintain constancy chemical composition and the intensity of the course of biological processes is

Answer: self-regulation.

50. The scientific assumption that can explain the observed data is

Answer: hypothesis.

51. A cell is a structural, functional unit of the living, a unit of growth and development - this is the position of ... theory.

Answer: cellular.

52. ATP synthesis in animal cells occurs in

Answer: mitochondria.

53. The similarity of the cells of fungi and animals is that they have ... a way of feeding.

Answer: Heterotrophic.

54. Elementary structural, functional and genetic unit alive is

Answer: cell.

55. An elementary open living system is

Answer: cell.

56. The elementary unit of reproduction and development is

Answer: cell.

57. The cell wall in plants is formed

Answer: cellulose.

58. At the basis of ideas about the unity of all living things lies ... theory.

Answer: cellular.

59. Microscope for biological research invented

Answer: R. Hooke (Hook).

60. The founder of microbiology is

Answer: L. Pasteur (Pasteur).

61. For the first time the term "cell" was used

Answer: R. Hooke (Hook).

62. Unicellular organisms discovered

Answer: A. Leeuwenhoek (Leuwenhoek).

63. "All new cells are formed by dividing the original" - this is the position of modern cell theory proved

Answer: R. Virchow.

64. M. Schleiden and T. Schwann formulated the main provisions of ... theory.

Answer: cellular.

65. A reserve substance in bacterial cells is

Answer: murein.

66. "Cells of all organisms are similar in chemical composition, structure and functions" - this is the position of ... theory.

Answer: cellular.

67. Bacteria, fungi, plants and animals are made up of cells, so a cell is called a unit

Answer: buildings.

68. Cells do NOT have a cell wall

Answer: animals.

69. All eukaryotic organisms are characterized by the presence in cells

Answer: nuclei.

70. They do NOT have a cellular structure

Answer: viruses.

71. Discovered the nucleus in plant cells

Answer: R. Brown (Brown).

72. In mushrooms, the reserve carbohydrate is

Answer: glycogen.

Kirilenko A. A. Biology. USE. Section "Molecular Biology". Theory, training tasks. 2017.

Everything you need to know about the OGE in biology in 2019, you can read - how to prepare, what to look for, why they can withdraw points, what the OGE participants advise last year.

Subscribe to us at contact and stay up to date with the latest news!

Biology(from 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.

The term “biology” is found in the works of the German anatomists T. Roose (1779) and K. F. Burdach (1800), but it was not until 1802 that it was first used independently by J. B. Lamarck and G. R. Treviranus to refer to the science that studies living organisms.

Biological Sciences

At present, biology includes a number of sciences that can be systematized according to the following criteria: according to the subject and prevailing research methods and according to the studied level of organization of living nature. According to the subject of study, 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. The main object of mycology are fungi, their structure and features of life. Lichenology- biological science that studies lichens. Bacteriology, virology and some aspects of mycology are often considered as part of microbiology - a branch of biology, the science of microorganisms (bacteria, viruses and microscopic fungi). Systematics, or taxonomy, is a 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 section of biology, the science of the individual development of an organism, including the development of an embryo.

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

According to the studied level of organization of wildlife, they distinguish molecular biology, cytology, histology, organology, biology of organisms and supraorganismal systems. Molecular biology is one of the youngest branches of biology, a science that studies, in particular, the organization of hereditary information and protein biosynthesis. Cytology, or cell biology, is a 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. The field of organology includes 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.

According to the prevailing research methods, one can single out 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 modern man and 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 treatment, 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 progress of other natural and exact sciences such as physics, chemistry, mathematics, computer science, etc. For example, microscopy, ultrasound research (ultrasound), tomography and other methods of biology are based on physical laws, and the study of the structure of biological molecules and processes occurring in living systems would be impossible without application 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.

Achievements in biology

The most important events in the field of biology that influenced the entire course of its further development are: the establishment of the molecular structure of DNA and its role in the transmission of information in living matter (F. Crick, J. Watson, M. Wilkins); deciphering the genetic code (R. Holly, H. G. Koran, M. Nirenberg); the discovery of the structure of the gene and the genetic regulation of protein synthesis (A. M. Lvov, F. Jacob, J. L. Monod, and others); formulation of the cell theory (M. Schleiden, T. Schwann, R. Virchow, K. Baer); study of the patterns of heredity and variability (G. Mendel, H. de Vries, T. Morgan, and others); formulation of the principles of modern systematics (C. Linnaeus), evolutionary theory (C. Darwin) and the doctrine of the biosphere (V. I. Vernadsky).

Significance of discoveries recent decades yet to be assessed, however, the most important achievements of biology have been recognized as: deciphering the genome of humans and other organisms, determining the mechanisms for controlling the flow of genetic information in the cell and the developing organism, the mechanisms for regulating cell division and death, cloning of mammals, as well as the discovery of causative agents of "mad cow disease" ( prions).

The work on the "Human Genome" program, which was carried out simultaneously in several countries and was completed at the beginning of this century, led us to understand that a person has about 25-30 thousand genes, but information from most of our DNA is never read , since it contains a huge number of sections and genes encoding features that have lost their significance for humans (tail, body hair, etc.). In addition, a number of genes responsible for the development of hereditary diseases, as well as drug target genes, have been deciphered. However, the practical application of the results obtained during the implementation of this program is postponed until the genomes of a significant number of people are decoded, and then it becomes clear what is their difference. These goals are set for a number of leading laboratories around the world working on the implementation of the ENCODE program.

Biological research is the foundation of medicine, pharmacy, and is widely used in agriculture, forestry, food industry and other branches of human activity.

It is well known that only the "green revolution" of the 1950s made it possible to at least partially solve the problem of providing the rapidly growing population of the Earth with food, and animal husbandry with feed through the introduction of new plant varieties and advanced technologies for their cultivation. Due to the fact that the genetically programmed properties of agricultural crops have almost been exhausted, the further solution of the food problem is associated with the widespread introduction of genetically modified organisms into production.

The production of many food products, such as cheeses, yogurts, sausages, bakery products, etc., is also impossible without the use of bacteria and fungi, which is the subject of biotechnology.

Knowledge of the nature of pathogens, the processes of the course of many diseases, the mechanisms of immunity, the laws of heredity and variability made it possible to significantly reduce mortality and even completely eradicate a number of diseases, such as smallpox. By using the latest achievements biological science also solves the problem of human reproduction.

A significant part of modern medicines is produced on the basis of natural raw materials, and also thanks to the success of genetic engineering, such as insulin, which is so necessary for patients with diabetes mellitus, is mainly synthesized by bacteria that have transferred the corresponding gene.

No less important are biological studies for the conservation environment and diversity of living organisms, the threat of extinction of which calls into question the existence of mankind.

Of greatest importance among the achievements of biology is the fact that they even underlie the construction of neural networks and the genetic code in computer technology, and are also widely used in architecture and other industries. Without a doubt, the 21st century is the century of biology.

Methods of knowledge of wildlife

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

The scientific method of cognition 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, that is, 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, and quantitative data are more accurate than qualitative ones.

Based on the observational data, we formulate hypothesis- 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 experimentation is modeling- 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 is based on the idea of modeling. scientific research both theoretical and experimental.

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 constituent 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 working hypothesis, and if it can resist attempts to refute it and still successfully predict previously unexplained facts and relationships, then it can become a 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 well-established theories can be challenged, modified, and even rejected, because they themselves scientific knowledge are inherently dynamic and constantly subject to critical rethinking.

historical method reveals patterns of appearance and development of organisms, formation of their structure and function. In some cases, this method new life acquire hypotheses and theories that were previously considered false. So, for example, it happened with Charles Darwin's assumptions about the nature of signal transmission through the plant in response to environmental influences.

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- this 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.

organism is a complete system capable of independent existence. According to the number of cells that make up organisms, they are divided into unicellular and multicellular. The cellular level of organization in unicellular organisms (common amoeba, green euglena, etc.) coincides with the organismic level. There was a period in the history of the Earth when all organisms were represented only by unicellular forms, but they ensured the functioning of both biogeocenoses and the biosphere as a whole. Most multicellular organisms are represented by a combination of tissues and organs, which in turn also have a cellular structure. Organs and tissues are adapted to perform certain functions. 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.

Population-species level

population- this is a collection of individuals of the same species, freely interbreeding with each other and living 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.

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. The biogeocenoses themselves are elementary units of a given level, while elementary phenomena are energy flows and cycles of substances in them. Biogeocenoses make up the biosphere and determine all the processes occurring in it.

biospheric level

Biosphere- 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 body, which in turn undergo the action of natural selection at the population-species level, etc.

Biological systems

Biological objects of varying degrees of complexity (cells, organisms, populations and species, biogeocenoses and the biosphere itself) are currently considered as biological systems.

A system is a unity of structural components, the interaction of which generates new properties in comparison with their mechanical combination. Organisms are made up of organs, organs are made up of tissues, and tissues make up cells.

Characteristic features of biological systems are their integrity, the level principle of organization, as mentioned above, and openness. The integrity of biological systems is largely achieved through self-regulation, functioning on the principle of feedback.

To open systems include systems between which and the environment there is an exchange of substances, energy and information, for example, plants in the process of photosynthesis capture sunlight and absorb water and carbon dioxide, releasing oxygen.

One of the fundamental concepts in modern biology is the idea that all living organisms have a cellular structure. Science deals with the study of the structure of the cell, its vital activity and interaction with the environment. cytology now commonly referred to as cell biology. Cytology owes its appearance to the formulation of the cell theory (1838–1839, M. Schleiden, T. Schwann, supplemented in 1855 by R. Virchow).

cell theory is a generalized idea of the structure and functions of cells as living units, their reproduction and role in the formation of multicellular organisms.

The main provisions of the cell theory:

A cell is a unit of structure, life activity, growth and development of living organisms - there is no life outside the cell. A cell is a single system consisting of many elements that are naturally connected with each other, representing a certain integral formation. The cells of all organisms are similar in their chemical composition, structure and functions. New cells are formed only as a result of division of mother cells (“cell from cell”). The cells of multicellular organisms form tissues, and organs are made up of tissues. The life of an organism as a whole is determined by the interaction of its constituent cells. The cells of multicellular organisms have a complete set of genes, but differ from each other in that different groups of genes work for them, which results in the morphological and functional diversity of cells - differentiation.

Thanks to the creation of the cellular theory, it became clear that the cell is the smallest unit of life, an elementary living system, which has all the signs and properties of living things. The formulation of the cell theory became the most important prerequisite for the development of views on heredity and variability, since the identification of their nature and their inherent patterns inevitably suggested the universality of the structure of living organisms. Revealing the unity of the chemical composition and structural plan of cells served as an impetus for the development of ideas about the origin of living organisms and their evolution. In addition, the origin of multicellular organisms from a single cell during embryonic development has become a dogma of modern embryology.

About 80 chemical elements are found in living organisms, but only 27 of these elements have their functions in the cell and organism. The rest of the elements are present in trace amounts, and appear to be ingested through food, water, and air. The content of chemical elements in the body varies significantly. Depending on the concentration, they are divided into macronutrients and microelements.

The concentration of each macronutrients in the body exceeds 0.01%, and their total content is 99%. Macronutrients include oxygen, carbon, hydrogen, nitrogen, phosphorus, sulfur, potassium, calcium, sodium, chlorine, magnesium, and iron. The first four of these elements (oxygen, carbon, hydrogen and nitrogen) are also called organogenic, since they are part of the main organic compounds. Phosphorus and sulfur are also components of a number of organic substances, such as proteins and nucleic acids. Phosphorus is essential for the formation of bones and teeth.

Without the remaining macronutrients, the normal functioning of the body is impossible. So, potassium, sodium and chlorine are involved in the processes of excitation of cells. Potassium is also needed for many enzymes to function and to retain water in the cell. Calcium is found in the cell walls of plants, bones, teeth, and mollusk shells and is required for muscle contraction and intracellular movement. Magnesium is a component of chlorophyll - a pigment that ensures the flow of photosynthesis. It also takes part in protein biosynthesis. Iron, in addition to being a part of hemoglobin, which carries oxygen in the blood, is necessary for the processes of respiration and photosynthesis, as well as for the functioning of many enzymes.

trace elements are contained in the body in concentrations of less than 0.01%, and their total concentration in the cell does not even reach 0.1%. Trace elements include zinc, copper, manganese, cobalt, iodine, fluorine, etc. Zinc is part of the pancreatic hormone molecule insulin, copper is required for photosynthesis and respiration. Cobalt is a component of vitamin B12, the absence of which leads to anemia. Iodine is necessary for the synthesis of thyroid hormones, which ensure the normal course of metabolism, and fluorine is associated with the formation of tooth enamel.

Both deficiency and excess or metabolic disorders of macro- and microelements lead to the development of various diseases. In particular, a lack of calcium and phosphorus causes rickets, a lack of nitrogen causes severe protein deficiency, an iron deficiency causes anemia, and a lack of iodine causes a violation of the formation of thyroid hormones and a decrease in metabolic rate. Reducing the intake of fluoride with water and food to a large extent causes a violation of the renewal of tooth enamel and, as a result, a predisposition to caries. Lead is toxic to almost all organisms. Its excess causes permanent damage to the brain and central nervous system, which is manifested by loss of vision and hearing, insomnia, kidney failure, seizures, and can also lead to paralysis and diseases such as cancer. Acute lead poisoning is accompanied by sudden hallucinations and ends in coma and death.

The lack of macro- and microelements can be compensated by increasing their content in food and drinking water, as well as by taking medications. So, iodine is found in seafood and iodized salt, calcium in eggshells, etc.

plant cells

Plants are eukaryotic organisms, therefore, their cells necessarily contain a nucleus at least at one of the stages of development. Also in the cytoplasm of plant cells there are various organelles, however, their distinguishing feature is the presence of plastids, in particular chloroplasts, as well as large vacuoles filled with cell sap. The main storage substance of plants - starch - is deposited in the form of grains in the cytoplasm, especially in the storage organs. Another essential feature of plant cells is the presence of cellulose cell membranes. It should be noted that in plants, formations, the living contents of which have died off, are also commonly called cells, but the cell walls remain. Often, these cell walls are impregnated with lignin during lignification, or with suberin during corking.

Plant tissues

Unlike animals, in plants the cells are glued together by a carbohydrate median lamina; between them there can also be intercellular spaces filled with air. During life, tissues can change their functions, for example, xylem cells first perform a conducting function, and then a supporting one. In plants, there are up to 20–30 types of tissues, uniting about 80 types of cells. Plant tissues are divided into educational and permanent.

Educational, or meristematic, tissues take part in plant growth processes. They are located at the tops of shoots and roots, at the bases of internodes, form a layer of cambium between the bast and wood in the stem, and also underlie the cork in lignified shoots. The constant division of these cells supports the process of unlimited plant growth: the educational tissues of the tips of the shoot and root, and in some plants, internodes, ensure the growth of plants in length, and the cambium in thickness. When a plant is damaged, from the cells that are on the surface, wound educational tissues are formed that fill the gaps that have arisen.

permanent fabrics plants specialize in performing certain functions, which is reflected in their structure. They are incapable of division, but under certain conditions they can again acquire this ability (with the exception of dead tissues). Permanent tissues include integumentary, mechanical, conductive and basic.

Integumentary tissues plants protect them from evaporation, mechanical and thermal damage, the penetration of microorganisms, and ensure the exchange of substances with the environment. Integumentary tissues include skin and cork.

Skin, or epidermis, is a single-layer tissue devoid of chloroplasts. The peel covers the leaves, young shoots, flowers and fruits. It is riddled with stomata and can carry various hairs and glands. The top of the skin is covered cuticle of fat-like substances that protect plants from excessive evaporation. Some hairs on its surface are also intended for this, while glands and glandular hairs can secrete various secrets, including water, salts, nectar, etc.

stomata- these are special formations through which water evaporates - transpiration. In stomata, the guard cells surround the stomatal opening, with free space below them. The guard cells of the stomata are most often bean-shaped, they contain chloroplasts and starch grains. The inner walls of the guard cells of the stomata are thickened. If the guard cells are saturated with water, then the inner walls stretch and the stomata open. Saturation of the guard cells with water is associated with the active transport of potassium ions and other osmotically active substances in them, as well as the accumulation of soluble carbohydrates in the process of photosynthesis. Through the stomata, not only the evaporation of water occurs, but also gas exchange in general - the supply and removal of oxygen and carbon dioxide, which penetrate further through the intercellular spaces and are consumed by cells in the process of photosynthesis, respiration, etc.

Cells traffic jams, which mainly covers lignified shoots, are impregnated with a fat-like substance suberin, which, on the one hand, causes cell death, and on the other hand, prevents evaporation from the plant surface, thereby providing thermal and mechanical protection. In the cork, as well as in the skin, there are special formations for ventilation - lentils. Cork cells are formed as a result of the division of the cork cambium that underlies it.

mechanical fabrics plants perform supporting and protective functions. These include collenchyma and sclerenchyma. Collenchyma is a living mechanical tissue with elongated cells with thickened cellulose walls. It is characteristic of young, growing plant organs - stems, leaves, fruits, etc. Sclerenchyma- this is a dead mechanical tissue, the living content of the cells of which dies due to the lignification of the cell walls. In fact, only thickened and lignified cell walls remain from sclerenchyma cells, which in the best possible way contributes to the performance of their respective functions. Cells of mechanical tissue are most often elongated and are called fibers. They accompany the cells of the conductive tissue in the composition of the bast and wood. Single or in groups stony cells sclerenchyma round or star-shaped are found in the immature fruits of pear, hawthorn and mountain ash, in the leaves of water lilies and tea.

By conductive tissue substances are transported throughout the body of the plant. There are two types of conductive tissue: xylem and phloem. Part xylem, or wood, includes conductive elements, mechanical fibers and cells of the main tissue. The living contents of the cells of the conducting elements of the xylem - vessels and tracheid- dies off early, only lignified cell walls remain from them, as in sclerenchyma. The function of the xylem is the upward transport of water and mineral salts dissolved in it from the root to the shoot. Phloem, or bast, is also a complex tissue, since it is formed by conductive elements, mechanical fibers and cells of the main tissue. Cells of conductive elements - sieve tubes- living, but the nuclei disappear in them, and the cytoplasm is mixed with cell sap to facilitate the transport of substances. The cells are located one above the other, the cell walls between them have numerous holes, which makes them look like a sieve, which is why the cells are called sieve. The phloem transports water and organic substances dissolved in it from the aboveground part of the plant to the root and other organs of the plant. Loading and unloading of sieve tubes is provided by adjacent companion cells. Main fabric not only fills the gaps between other tissues, but also performs nutritional, excretory and other functions. The nutritional function is performed by photosynthetic and storage cells. For the most part this parenchymal cells, i.e. they have almost the same linear dimensions: length, width and height. The main tissues are located in leaves, young stems, fruits, seeds and other storage organs. Some types of basic tissue are capable of performing a suction function, such as cells of the hairy layer of the root. The selection is carried out by a variety of hairs, glands, nectaries, resin passages and receptacles. A special place among the main tissues belongs to lactic cells, in the cell juice of which rubber, gutta, and other substances accumulate. In aquatic plants, the intercellular spaces of the main tissue may grow, as a result of which large cavities are formed, with the help of which ventilation is carried out.

plant organs

Vegetative and generative organs

Unlike animals, the body of plants is divided into a small number of organs. They are divided into vegetative and generative. Vegetative organs support the vital activity of the organism, but do not participate in the process of sexual reproduction, while generative organs perform exactly this function. The vegetative organs include the root and shoot, and the generative (in flowering) - flower, seed and fruit.

Root

Root- this is an underground vegetative organ that performs the functions of soil nutrition, fixing the plant in the soil, transport and storage of substances, as well as vegetative propagation.

Root morphology. The root has four zones: growth, absorption, conduction and root cap. root cap protects the cells of the growth zone from damage and facilitates the movement of the root among the solid soil particles. It is represented by large cells that can become slimy and die over time, which facilitates root growth.

growth zone is made up of cells capable of dividing. Some of them, after division, increase in size as a result of stretching and begin to perform their inherent functions. Sometimes the growth zone is divided into two zones: division and stretching.

AT suction zone root hair cells are located, performing the function of water absorption and minerals. Root hair cells do not live long, desquamating 7–10 days after formation.

AT the venue, or lateral roots, substances are transported from the root to the shoot, and branching of the root also occurs, i.e., the formation of lateral roots, which contributes to the anchoring of the plant. In addition, in this zone, it is possible to store substances and lay buds, with the help of which vegetative propagation can occur.

Send your good work in the knowledge base is simple. Use the form below

Students, graduate students, young scientists who use the knowledge base in their studies and work will be very grateful to you.

Hosted at http://www.allbest.ru

1. What does anatomy study?

Human anatomy is the science of the form, structure and development of the human body in accordance with gender, age and individual characteristics.

Anatomy studies the external forms and proportions of the human body and its parts, individual organs, their design, microscopic structure. The tasks of anatomy include the study of the main stages of human development in the process of evolution, the structural features of the body and individual organs at different age periods, as well as in environmental conditions.

2. What does physiology study?

Physiology - (from the Greek physis - nature and logos - word, doctrine), the science of life processes and the mechanisms of their regulation in the human body. Physiology studies mechanisms various functions of a living organism (growth, reproduction, respiration, etc.), their relationship with each other, regulation and adaptation to the external environment, origin and formation in the process of evolution and individual development of an individual. Solving fundamentally common problems, the physiology of animals and humans and the physiology of plants have differences due to the structure and functions of their objects. So, for the physiology of animals and humans, one of the main tasks is the study of the regulatory and integrating role of the nervous system in the body. The greatest physiologists participated in solving this problem (I.M. Sechenov, N.E. Vvedensky, I.P. Pavlov, A.A. Ukhtomsky, G. Helmholtz, K. Bernard, C. Sherrington, etc.). For plant physiology, which emerged from botany in the 19th century, it is traditional to study mineral (root) and air (photosynthesis) nutrition, flowering, fruiting, etc. It serves theoretical basis crop production and agronomy. The founders of Russian plant physiology - A.S. Famintsyn and K.A. Timiryazev. Physiology is associated with anatomy, cytology, embryology, biochemistry, and other biological sciences.

3. What does hygiene study?

Hygiene - (from other Greek ? geinyu "healthy", from? gyaeb "health") - the science of the influence of the environment on human health.

As a result, hygiene has two objects of study - environmental factors and the reaction of the body, and uses the knowledge and methods of physics, chemistry, biology, geography, hydrogeology and other sciences that study the environment, as well as physiology, anatomy and pathophysiology.

Environmental factors are diverse and are divided into:

· Physical -- noise, vibration, electromagnetic and radioactive radiation, climate, etc.

Chemical - chemical elements and their compounds.

· Factors of human activity - the regime of the day, the severity and intensity of labor, etc.

· Social.

Within the framework of hygiene, the following main sections are distinguished:

Environmental hygiene - studying the impact of natural factors - atmospheric air, solar radiation, etc.

· Occupational health - studying the impact of the working environment and factors of the production process on a person.

Communal hygiene - within the framework of which requirements are developed for urban planning, housing, water supply, etc.

· Nutritional hygiene - studying the meaning and impact of food, developing measures to optimize and ensure nutritional safety (often this section is confused with dietetics).

· Hygiene of children and adolescents - studying the complex impact of factors on a growing organism.

· Military hygiene -- aimed at maintaining and improving the combat capability of personnel.

Personal hygiene - a set of hygiene rules, the implementation of which contributes to the preservation and promotion of health.

Also some narrow sections: radiation hygiene, industrial toxicology, etc.

The main tasks of hygiene:

study of the influence of the external environment on the state of health and performance of people. At the same time, the external environment should be understood as the whole complex complex of natural, social, domestic, industrial and other factors.

· scientific rationale and development of hygienic standards, rules and measures to improve the environment and eliminate harmful factors;

· scientific justification and development of hygienic standards, rules and measures to increase the body's resistance to possible harmful environmental influences in order to improve health and physical development, increase efficiency. This is facilitated by rational nutrition, physical exercises, hardening, a properly organized work and rest regimen, and observance of personal hygiene rules.

4. What factors disturbing the balance between the environment and the organism are toxins?

In the body of each person there is a certain amount of harmful substances, which are called toxins (from the Greek. toxikon - poison). They are divided into two large groups.

Exotoxins are harmful substances of chemical and natural origin that enter the body from the external environment with food, air or water. Most often, these are nitrates, nitrites, heavy metals and many others chemical compounds present in almost everything that surrounds us. Living in large industrial cities, working in hazardous industries, and even taking medications containing toxic substances are all, to one degree or another, factors of poisoning the body.

Endotoxins are harmful substances that are formed during the life of the body. Especially a lot of them appear in various diseases and metabolic disorders, in particular, with bad job intestines, deviations in the functioning of the liver, with tonsillitis, pharyngitis, influenza, acute respiratory infections, kidney disease, allergic conditions, even stress.

Toxins poison the body and disrupt its coordinated work - most often they undermine the immune, hormonal, cardiovascular and metabolic systems. This leads to a complication of the course of various diseases and prevents recovery. Toxins lead to a decrease in the body's resistance, deterioration of the general condition and loss of strength.

One theory of aging suggests that it is caused by the accumulation of toxins in the body. They inhibit the work of organs, tissues, cells, disrupt the course of biochemical processes in them. This ultimately leads to a deterioration in their functions and, as a result, to aging of the whole organism.

Almost any disease is much easier and easier to treat if toxins do not accumulate and are quickly eliminated from the body.

Nature has endowed man with various systems and organs capable of destroying, neutralizing and removing harmful substances from the body. These are, in particular, the systems of the liver, kidneys, lungs, skin, gastrointestinal tract, etc. In modern conditions, it is becoming increasingly difficult to cope with aggressive toxins, and a person needs additional reliable and effective help.

5. What factors does radiation refer to?

Radioactivity is called the instability of the nuclei of some atoms, which manifests itself in their ability to spontaneous transformation (according to scientific - decay), which is accompanied by the release of ionizing radiation (radiation). The energy of such radiation is large enough, so it is able to act on the substance, creating new ions of different signs. Induce radiation with chemical reactions no, it's a completely physical process.

There are several types of radiation:

· Alpha particles are relatively heavy particles, positively charged, are helium nuclei.

Beta particles are ordinary electrons.

· Gamma radiation - has the same nature as visible light, but much greater penetrating power.

· Neutrons are electrically neutral particles that occur mainly near a working nuclear reactor, access there should be limited.

· X-rays are similar to gamma rays, but have less energy. By the way, the Sun is one of natural sources such rays, but the Earth's atmosphere provides protection from solar radiation.

Sources of radiation - nuclear installations (particle accelerators, reactors, X-ray equipment) and radio active substances. They can exist for a considerable time without manifesting themselves in any way, and you may not even suspect that you are near an object of strong radioactivity.

The body reacts to the radiation itself, and not to its source. radioactive substances can enter the body through the intestines (with food and water), through the lungs (during breathing) and even through the skin during medical diagnostics with radioisotopes. In this case, internal radiation occurs. In addition, a significant effect of radiation on the human body is exerted by external exposure, i.e. The radiation source is outside the body. The most dangerous, of course, is internal exposure.

The effect of radiation on the human body is called irradiation. During this process, the energy of the radiation is transferred to the cells, destroying them. Irradiation can cause all sorts of diseases: infectious complications, metabolic disorders, malignant tumors and leukemia, infertility, cataracts and much more. Radiation is especially acute on dividing cells, so it is especially dangerous for children.

Radiation refers to those factors of physiological effects on the human body, for the perception of which it has no receptors. He is simply not able to see, hear, or feel it by touch or taste.

The absence of direct cause-and-effect relationships between radiation and the body's response to its effects allows us to constantly and quite successfully exploit the idea of the danger of low doses affecting human health.

6. What factors are viruses?

Viruses (derived from the Latin virus - “poison”) are the smallest microorganisms that do not have a cellular structure, a protein-synthesizing system and are capable of reproducing only in the cells of highly organized life forms. To designate an agent capable of causing an infectious disease, it was first used in 1728.

The origin of viruses in the evolutionary tree of life is unclear: some of them may have originated from plasmids, small DNA molecules that can be transferred from one cell to another, while others may have originated from bacteria. In evolution, viruses are an important means of horizontal gene transfer, which determines genetic diversity.

Viruses spread in many ways: plant viruses are often transmitted from plant to plant by insects that feed on plant sap, such as aphids; Animal viruses can be spread by blood-sucking insects, such organisms are known as vectors. The influenza virus is spread through the air through coughs and sneezes. Norovirus and rotavirus, which commonly cause viral gastroenteritis, are transmitted by the fecal-oral route through contact with contaminated food or water. HIV is one of several viruses transmitted through sexual contact and through transfusion of infected blood. Each virus has a specific host specificity, determined by the types of cells it can infect. The host range may be narrow or, if the virus infects many species, wide.

Viruses, although very small, they cannot be seen, are the object of study of the sciences:

For physicians, viruses are the most common causative agents of infectious diseases: influenza, measles, smallpox, tropical fevers.

For a pathologist, viruses are the etiological agents (cause) of cancer and leukemia, the most frequent and dangerous pathological processes.

For a veterinarian, viruses are the culprits of epizootics (mass diseases) of foot-and-mouth disease, bird plague, infectious anemia and other diseases that affect farm animals.

For an agronomist, viruses are the causative agents of spotted banding of wheat, tobacco mosaic, yellow potato dwarfism and other diseases of agricultural plants.

For the grower, viruses are the factors that cause the amazing colors of tulips to appear.

For the medical microbiologist, viruses are agents that cause the appearance of toxic (poisonous) varieties of diphtheria or other bacteria, or factors that contribute to the development of antibiotic-resistant bacteria.

For an industrial microbiologist, viruses are pests of bacteria, producers, antibiotics, and enzymes.

For a geneticist, viruses are carriers of genetic information.

For a Darwinist, viruses are important factors in the evolution of the organic world.

For an ecologist, viruses are factors involved in the formation of conjugated systems of the organic world.

For a biologist, viruses are the simplest forms of life, possessing all of its main manifestations.

For a philosopher, viruses are the clearest illustration of the dialectics of nature, a touchstone for polishing such concepts as living and nonliving, part and whole, form and function.

Viruses are the causative agents of the most important diseases of humans, farm animals and plants, and their importance is constantly increasing as the incidence of bacterial, protozoal and fungal diseases decreases.

7. What is homeostasis?

Life is possible only with a relatively small range of deviations various characteristics internal environment - physical and chemical (acidity, osmotic pressure, temperature, etc.) and physiological (arterial pressure, blood sugar, etc.) - from a certain average value. The constancy of the internal environment of a living organism is called homeostasis (from the Greek words homoios - similar, identical and stasis - state).

Under the influence of environmental factors, the vital characteristics of the internal environment may change. Then reactions occur in the body aimed at restoring them or preventing such changes. These reactions are called homeostatic. When blood is lost, for example, vasoconstriction occurs, preventing a drop in blood pressure. With an increase in sugar consumption during physical work its release into the blood from the liver increases, which prevents a drop in blood sugar levels. With an increase in heat production in the body, the skin vessels expand, and therefore heat transfer increases, which prevents the body from overheating.

Homeostatic reactions are organized by the central nervous system, which regulates the activity of the autonomic and endocrine systems. The latter already directly affect the tone of blood vessels, the intensity of metabolism, the work of the heart and other organs. The mechanisms of the same homeostatic reaction and their effectiveness can be different and depend on many factors, including hereditary ones.

Homeostasis is also called the preservation of the constancy of the species composition and the number of individuals in biocenoses, the ability of a population to maintain a dynamic balance of the genetic composition, which ensures its maximum viability (genetic homeostasis).

8. What is a cytolemma?

The cytolemma is the universal skin of the cell, it performs barrier, protective, receptor, excretory functions, transfers nutrients, transmits nerve impulses and hormones, connects cells into tissues.

This is the thickest (10 nm) and complexly organized cell membrane. It is based on a universal biological membrane, covered on the outside with a glycocalyx, and on the inside, from the side of the cytoplasm, with a submembrane layer. The glycocalyx (3-4 nm thick) is represented by the outer, carbohydrate sections of complex proteins - glycoproteins and glycolipids that make up the membrane. These carbohydrate chains play the role of receptors that ensure that the cell recognizes neighboring cells and intercellular substance and interacts with them. This layer also includes surface and semi-integral proteins, the functional sites of which are located in the supramembrane zone (for example, immunoglobulins). The glycocalyx contains histocompatibility receptors, receptors for many hormones and neurotransmitters.

The submembrane, cortical layer is formed by microtubules, microfibrils and contractile microfilaments, which are part of the cell cytoskeleton. The submembrane layer maintains the shape of the cell, creates its elasticity, and provides changes in the cell surface. Due to this, the cell participates in endo- and exocytosis, secretion, and movement.

The cytolemma performs many functions:

1) delimiting (the cytolemma separates, delimits the cell from the environment and ensures its connection with the external environment);

2) recognition by this cell of other cells and attachment to them;

3) recognition by the cell of the intercellular substance and attachment to its elements (fibers, basement membrane);

4) transport of substances and particles into and out of the cytoplasm;

5) interaction with signal molecules (hormones, mediators, cytokines) due to the presence of specific receptors for them on its surface;

6) provides cell movement (formation of pseudopodia) due to the connection of the cytolemma with the contractile elements of the cytoskeleton.

Numerous receptors are located in the cytolemma, through which biologically active substances (ligands, signal molecules, first mediators: hormones, mediators, growth factors) act on the cell. Receptors are genetically determined macromolecular sensors (proteins, glyco- and lipoproteins) built into the cytolemma or located inside the cell and specialized in the perception of specific signals of a chemical or physical nature. Biologically active substances, when interacting with the receptor, cause a cascade of biochemical changes in the cell, while transforming into a specific physiological response (change in cell function).

All receptors have a common structural plan and consist of three parts: 1) supramembrane, interacting with a substance (ligand); 2) intramembrane, carrying out signal transfer; and 3) intracellular, immersed in the cytoplasm.

9. What is the importance of the core?

The nucleus is an obligatory component of the cell (exception: mature erythrocytes), where the bulk of DNA is concentrated.

Two important processes take place in the nucleus. The first of these is the synthesis of the genetic material itself, during which the amount of DNA in the nucleus doubles (for DNA and RNA, see Nucleic acids). This process is necessary so that during subsequent cell division (mitosis), the two daughter cells have the same amount of genetic material. The second process - transcription - is the production of all types of RNA molecules, which, migrating into the cytoplasm, provide the synthesis of proteins necessary for the life of the cell.

The nucleus differs from the cytoplasm surrounding it in terms of the refractive index of light. That is why it can be seen in a living cell, but usually special dyes are used to identify and study the nucleus. The Russian name "nucleus" reflects the spherical shape most characteristic of this organoid. Such nuclei can be seen in liver cells, nerve cells, but in smooth muscle and epithelial cells, the nuclei are oval. There are nuclei and more bizarre shapes.

The most dissimilar nuclei are composed of the same components, i.e. have a common building plan. In the nucleus, there are: nuclear membrane, chromatin (chromosome material), nucleolus and nuclear juice. Each nuclear component has its own structure, composition and functions.

The nuclear membrane includes two membranes located at some distance from each other. The space between the membranes of the nuclear envelope is called the perinuclear space. There are holes in the nuclear membrane - pores. But they are not end-to-end, but are filled with special protein structures, which are called the nuclear pore complex. Through the pores, RNA molecules exit the nucleus into the cytoplasm, and proteins move towards them into the nucleus. The membranes of the nuclear envelope themselves ensure the diffusion of low molecular weight compounds in both directions.

Chromatin (from the Greek word chroma - color, paint) is the substance of chromosomes, which are much less compact in the interphase nucleus than during mitosis. When cells are stained, they are stained brighter than other structures.

The nucleolus is clearly visible in the nuclei of living cells. It has the form of a round body irregular shape and clearly stands out against the background of a fairly homogeneous core. The nucleolus is a formation that occurs in the nucleus on those chromosomes that are involved in the synthesis of RNA ribosomes. The region of the chromosome that forms the nucleolus is called the nucleolar organizer. In the nucleolus, not only RNA synthesis takes place, but also the assembly of ribosome subparticles. The number of nucleoli and their sizes can be different. The products of the activity of chromatin and the nucleolus initially enter the nuclear juice (karyoplasm).

The nucleus is essential for cell growth and reproduction. If the main part of the cytoplasm is separated experimentally from the nucleus, then this cytoplasmic lump (cytoplast) can exist without a nucleus for only a few days. The nucleus, surrounded by the narrowest rim of the cytoplasm (karyoplast), completely retains its viability, gradually ensuring the restoration of organelles and the normal volume of the cytoplasm. Nevertheless, some specialized cells, such as mammalian erythrocytes, function for a long time without a nucleus. It is also deprived of platelets - platelets, which are formed as fragments of the cytoplasm of large cells - megakaryocytes. Spermatozoa have a nucleus, but it is completely inactive.

10. What is fertilization?

Fertilization is the fusion of a male reproductive cell (sperm) with a female (ovum), leading to the formation of a zygote, which gives rise to a new organism. Fertilization is preceded by complex processes of egg maturation (oogenesis) and spermatozoon (spermatogenesis). Unlike sperm, the egg does not have independent mobility. A mature egg is released from the follicle into the abdominal cavity in the middle menstrual cycle at the time of ovulation and enters the fallopian tube due to its suction peristaltic movements and the flickering of cilia. The period of ovulation and the first 12-24 hours. after it are the most favorable for fertilization. If it does not happen, then in the following days regression and death of the egg occur.

During sexual intercourse, semen (semen) enters the woman's vagina. Under the influence of the acidic environment of the vagina, part of the spermatozoa dies. The most viable of them penetrate through the cervical canal into the alkaline environment of its cavity and 1.5-2 hours after sexual intercourse reach the fallopian tubes, in the ampullary section of which fertilization occurs. Many spermatozoa rush to the mature egg, however, as a rule, only one of them penetrates through the shiny membrane covering it, the nucleus of which merges with the nucleus of the egg. From the moment of the fusion of germ cells, pregnancy begins. A unicellular embryo is formed, a qualitatively new cell - a zygote, from which, as a result of a complex process of development during pregnancy, a human body is formed. The sex of the unborn child depends on the type of sperm that fertilized the egg, which is always the carrier of the X chromosome. In the event that the egg was fertilized by a sperm with the X (female) sex chromosome, a female embryo (XX) occurs. When an egg is fertilized by a sperm with a Y (male) sex chromosome, a male embryo (XY) develops. There is evidence that spermatozoa containing the Y chromosome are less durable and die faster compared to spermatozoa containing the X chromosome. Obviously, in this regard, the likelihood of conceiving a boy increases if the fertilizing sexual intercourse occurred during ovulation. In the event that sexual intercourse was a few days before ovulation, there is a greater chance that fertilization will occur. Eggs are sperm cells containing the X chromosome, i.e., a higher probability of having a girl.

The fertilized egg, moving along the fallopian tube, undergoes crushing, passes through the stages of blastula, morula, blastocyst, and on the 5-6th day from the moment of fertilization reaches the uterine cavity. At this point, the embryo (embryoblast) is covered on the outside with a layer of special cells - the trophoblast, which provides nutrition and implantation (introduction) into the uterine mucosa, which is called decidual during pregnancy. The trophoblast secretes enzymes that dissolve the uterine ileus, which facilitates the immersion of the fertilized egg into its thickness.

11. What characterizes the crushing stage?

Cleavage is a series of rapid divisions of the zygote without intermediate growth.

After combining the genomes of the egg and sperm, the zygote immediately proceeds to mitotic division - the development of a multicellular diploid organism begins. The first stage of this development is called fragmentation. It has a number of features. First of all, in most cases cell division does not alternate with cell growth. The number of cells of the embryo increases, and its total volume remains approximately equal to the volume of the zygote. During cleavage, the volume of the cytoplasm remains approximately constant, while the number of nuclei, their total volume, and in particular the surface area, increase. This means that during the period of crushing, normal (ie, characteristic of somatic cells) nuclear-plasma relations are restored. Mitoses in the course of crushing especially quickly follow one after another. This occurs due to the shortening of the interphase: the Gx period falls out completely, and the G2 period also shortens. Interphase is practically reduced to the S-period: as soon as the entire DNA doubles, the cell enters mitosis.

Cells formed during crushing are called blastomeres. In many animals, they divide synchronously for quite a long time. True, sometimes this synchrony is disturbed early: for example, in the roundworm at the stage of four blastomeres, and in mammals the first two blastomeres already divide asynchronously. In this case, the first two divisions usually occur in the meridional planes (pass through the animal-vegetative axis), and the third division - in the equatorial (perpendicular to this axis).

Another one feature crushing - the absence of signs of tissue differentiation in blastomeres. Cells can already "know" their future fate, but they do not yet have signs of nerve, muscle or epithelial.

12. What is implantation?

physiology cytolemma zygote

Implantation (from Latin in (im) - in, inside and plantatio - planting, transplantation), attachment of the embryo to the wall of the uterus in mammals with intrauterine development and in humans.

There are three types of implantation:

Central implantation - when the embryo remains in the lumen of the uterus, attaching to its wall or the entire surface of the trophoblast, or only part of it (in bats, ruminants).

Eccentric implantation - the embryo penetrates deep into the fold of the uterine mucosa (the so-called uterine crypt), the walls of which then fuse over the embryo and form an implantation chamber isolated from the uterine cavity (in rodents).

Interstitial implantation - characteristic of higher mammals (primates and humans) - the embryo actively destroys the cells of the uterine mucosa and is introduced into the resulting cavity; the defect of the uterus heals, and the embryo is completely immersed in the wall of the uterus, where its further development takes place.

13. What is gastrulation?

Gastrulation is a complex process of morphogenetic changes, accompanied by reproduction, growth, directed movement and differentiation of cells, resulting in the formation of germ layers (ectoderm, mesoderm and endoderm) - sources of rudiments of tissues and organs. The second stage of ontogenesis after crushing. During gastrulation, the movement of cell masses occurs with the formation of a two-layer or three-layer embryo from the blastula - the gastrula.

The type of blastula determines the mode of gastrulation.

The embryo at this stage consists of clearly separated layers of cells - germ layers: outer (ectoderm) and inner (endoderm).

In multicellular animals, except for intestinal cavities, in parallel with gastrulation or, like in the lancelet, after it, a third germ layer appears - the mesoderm, which is a collection of cellular elements located between the ectoderm and endoderm. Due to the appearance of the mesoderm, the embryo becomes three-layered.

In many groups of animals, it is at the stage of gastrulation that the first signs of differentiation appear. Differentiation (differentiation) is the process of the emergence and growth of structural and functional differences between individual cells and parts of the embryo.

From the ectoderm, the nervous system, sensory organs, skin epithelium, tooth enamel are formed; from the endoderm - the epithelium of the middle intestine, digestive glands, the epithelium of the gills and lungs; from the mesoderm - muscle tissue, connective tissue, circulatory system, kidneys, sex glands, etc.

In different groups of animals, the same germ layers give rise to the same organs and tissues.

Gastrulation methods:

Invagination - occurs by invagination of the blastula wall into the blastocoel; characteristic of most groups of animals.

· Delamination (characteristic of coelenterates) - the cells located outside are transformed into the epithelial layer of the ectoderm, and the endoderm is formed from the remaining cells. Usually, delamination is accompanied by divisions of blastula cells, the plane of which passes "at a tangent" to the surface.

Immigration - migration of individual cells of the blastula wall into the blastocoel.

Unipolar - on one section of the blastula wall, usually on the vegetative pole;

· Multipolar - on several parts of the blastula wall.

Epiboly - fouling of some cells by rapidly dividing other cells or fouling of cells of the internal mass of the yolk (with incomplete crushing).

· Involution - screwing inside the embryo of the outer layer of cells increasing in size, which spreads along the inner surface of the cells remaining outside.

Hosted on Allbest.ru

...

Glossary of basic biological terms and concepts

BUT

ABIOTIC ENVIRONMENT - a set of inorganic conditions (factors) for the habitat of organisms. These include the composition of atmospheric air, the composition of sea and fresh water, soil, air and soil temperature, lighting and other factors.

AGROBIOCENOSIS - a set of organisms living on lands occupied by crops and planting crops. In agriculture, the vegetation cover is created by man and usually consists of one or two cultivated plants and accompanying weeds.

AGROECOLOGY is a branch of ecology that studies the patterns of organization of artificial plant communities, their structure and functioning.

NITROGEN-FIXING BACTERIA - bacteria capable of assimilating atmospheric nitrogen with the formation of nitrogen compounds available for use by other organisms. Among A.b. there are both free-living in the soil and coexisting with mutual benefit with the roots higher plants.

ANTIBIOTICS are specific chemical substances formed by microorganisms and capable of exerting a selective effect on other microorganisms and malignant tumor cells even in small quantities. In a broad sense, A. also includes antimicrobial substances in the tissues of higher plants (phytoncides). The first A. was obtained in 1929 by Fleming (although penicillium was used by Russian doctors much earlier). The term "A." proposed in 1942 by Z. Waksman.

ANTHROPOGENIC FACTORS - factors of human influence on the environment. Human influence on plants can be both positive (plant cultivation, pest control, protection of rare species and biocenoses) and negative. The negative impact of a person can be direct - deforestation, collecting flowering plants, trampling vegetation in parks and forests, indirect - through environmental pollution, the destruction of pollinating insects, etc.

BACTERIA is the kingdom of living organisms. They differ from organisms of other kingdoms in the structure of the cell. Single-celled or grouped microorganisms. Motionless or mobile - with flagella.

BACTERICIDITY - the ability of plant juices, blood serum of animals and some chemical substances kill bacteria.

BIO-INDICATORS - organisms whose developmental characteristics or number serve as indicators of natural processes or anthropogenic changes in the environment. Many organisms can exist only within certain, often narrow limits of changes in environmental factors (the chemical composition of soil, water, atmosphere, climatic and weather conditions, the presence of other organisms). For example, lichens and some coniferous trees serve B. to keep the air clean. Aquatic plants, their species composition and abundance are B. the degree of water pollution.

BIOMASS - the total mass of individuals of a species, group of species or community of organisms. It is usually expressed in units of mass (grams, kilograms) per unit area or volume of habitat (hectare, cubic meter). About 90% of biospheres of the entire biosphere are terrestrial plants. The rest is aquatic vegetation.

BIOSPHERE - the area of distribution of life on Earth, the composition, structure and energy of which are determined by the joint activity of living organisms.

BIOCENOSIS - a set of plants and animals that has developed in the process of evolutionary development in the food chain, affecting each other in the course of the struggle for existence and natural selection (plants, animals and microorganisms that inhabit the lake, river valley, pine forest).

VIEW - the basic unit in the taxonomy of living organisms. A set of individuals that have a number of common characteristics and are capable of interbreeding with the formation of fertile offspring, inhabiting a certain territory.

germination - the ability of seeds to produce normal seedlings within a specified period under certain conditions. Express germination as a percentage.

HIGHER PLANTS - complex multicellular organisms with well-defined vegetative organs, adapted, as a rule, to life in a terrestrial environment.

GAMETE - sex cell. Provides transmission of hereditary information from parents to descendants.

Gametophyte - sexual generation in the life cycle of plants that develop with alternation of generations. Formed from spores, produces gametes. In higher plants, only in mosses, hyphae is represented by a leafy plant. In others, it is poorly developed and short-lived. In club mosses, horsetails, and ferns, G. is a growth that produces both male and female gametes. In angiosperms, the female G. is the embryo sac, and the male is pollen. They grow along the banks of rivers, in swamps and wet fields (reed, cattail).

GENERATIVE ORGANS - organs that perform the function of sexual reproduction. In flowering plants - flowers and fruits, more precisely - a speck of dust and an embryo sac.

HYBRIDIZATION - combining the hereditary material of different cells into one. In agriculture, the crossing of different varieties of plants. See also Selection.

Hygrophytes - plants of wet habitats. They grow in swamps, in water, in tropical rainforests. They have a poorly developed root system. Wood and mechanical fabrics are poorly developed. They can absorb moisture from the entire surface of the body.

HYDROPHYTES - aquatic plants attached to the ground and immersed in water only at the bottom. Unlike hygrophytes, they have well-developed conductive and mechanical tissues, a root system. But there are many intercellular spaces and air cavities.

GLYCOGEN - carbohydrate, polysaccharide. Its branched molecules are built from glucose residues. Energy reserve of many living organisms. When it is broken down, glucose (sugar) is formed and energy is released. Found in the liver and muscles of vertebrates, in fungi (yeast), in algae, in the grain of some varieties of corn.

GLUCOSE - grape sugar, one of the most common simple sugars. In green plants, it is formed from carbon dioxide and water as a result of photosynthesis. Participates in many metabolic reactions.

Gymnosperms are the most ancient of seed plants. Most are evergreen trees and shrubs. Representatives of gymnosperms are coniferous plants (spruce, pine, cedar, fir, larch).

MUSHROOMS - the kingdom of living organisms. Combine signs of both plants and animals, and also have special signs. There are both unicellular and multicellular fungi. The body (mycelium) consists of a system of branching filaments.

HUMUS (HUMUS) - a complex of specific dark-colored organic substances of the soil. It is obtained as a result of the transformation of organic residues. To a large extent determines the fertility of the soil.

The first task corresponds to the first section in the codifier, which can be easily found on the FIPI website.

The section is called “Biology as a science. Methods of scientific knowledge”. What does this mean? There are no specifics here, so, in fact, it can include anything.

In the codifier, you can find a list of content elements that are checked for the exam. That is, everything you need to know to successfully complete the task is listed there. For correct execution, you can get 1 point.

We present them below for your reference:

Biology as a science, its achievements, methods of cognition of living nature.
The role of biology in the formation of the modern natural-science picture of the world.
Level organization and evolution. The main levels of organization of living nature: cellular, organismic, population-species, biogeocenotic, biospheric.
Biological systems. General features of biological systems: cellular structure, chemical composition, metabolism and energy conversion, homeostasis, irritability, movement, growth and development, reproduction, evolution.

It looks very complicated and incomprehensible, however, in the process of preparation, you will still get acquainted with all these topics, they do not need to be taught for a separate task.

Analysis of typical tasks No. 1 USE in biology

After reviewing all the tasks offered by the open bank, we can distinguish two classifications of tasks for ourselves: according to the thematic section and according to the form of the question.

By subject area

Arranged in order from largest to smallest, we get:

Botany
human anatomy
Cytology
General biology
Genetics
Evolution

Let's look at examples of tasks for each section.

Botany

Consider the proposed diagram of the structure of the organs of a flowering plant. Write in the answer the missing term, indicated in the diagram with a question mark.

The stem, buds and leaves together make up the ground part of the plant - the shoot.

Answer: escape.

human anatomy

Consider the proposed scheme of the structure of the skeleton of the upper limb. Write in the answer the missing term, indicated in the diagram with a question mark.

The arm belongs to the free upper limb. If you don’t go into details with the bones that make it up yet, then you just need to remember the three sections: shoulder, forearm, hand.

The shoulder begins at the shoulder joint and ends at the elbow joint.

The forearm, respectively, should end with the elbow, and start from the wrist inclusive.

Brush-bones that make up the palm and phalanges of the fingers.

Answer: shoulder.

Cytology

First, you need to familiarize yourself with the concept of "cytology" in order to understand what in question.

Cytology is a branch of biology that studies living cells, their organelles, their structure, functioning, processes of cell reproduction, aging and death. The terms cell biology, cell biology are also used.

The word "cytology" includes two roots from the Greek language: "cytos" - cell, "logos" - science, as in biology - "bio" - living, "logos" - science. Knowing the roots, you can easily assemble a definition.

Consider the proposed classification scheme for organelles. Write in the answer the missing term, indicated by a question mark in the diagram.

From this diagram, it becomes clear that organelles are divided into three types according to the number of membranes. Here, only one window is allocated for each type, but this does not mean that only one organoid corresponds to each type. In addition, plant and animal cells have differences in cell structure.

Plants, unlike animals, have:

Cellulose cell wall
Chloroplasts essential for photosynthesis
Large digestive vacuole. The older the cell, the larger the vacuoles

According to the number of membranes, organelles are divided into:

Single-membrane organelles: endoplasmic reticulum, Golgi complex, lysosomes.
Two-membrane organelles: nucleus, mitochondria, plastids (leukoplasts, chloroplasts, chromoplasts).
Non-membrane organelles: ribosomes, centrioles, nucleolus.

In the diagram, the question is about two-membrane organelles. We know that mitochondria and plastids are two-membrane. We argue: there is only one pass, and there are two options. It's not just like that. You need to read the question carefully. There are two types of cells, but we are not told which one we are talking about, so the answer must be universal. Plastids are characteristic only of plant cells, therefore, mitochondria remain.

Answer: mitochondria, or mitochondrion.

(Both options are listed in the open bank)

Genetics

Again, let's look at the definition:

Genetics is the science of the laws of heredity and variability.

Let's break the definition into definitions:

Heredity - The totality of the natural properties of an organism received from parents, predecessors.

Variability - a variety of characters among representatives of a given species, as well as the property of offspring to acquire differences from parental forms.

Consider the proposed classification scheme for the types of variability. Write in the answer the missing term, indicated in the diagram with a question mark.

Since the property of acquiring differences from parental forms is embedded in the concept of variability, this gives us the term "heredity". A healthy person has 46 chromosomes. 23 from mom, 23 from dad. This means that the child is a combination of traits acquired from parents, moreover, mom and dad also carry the traits of their parents in their genetic code. In the course of permutations, some appear in the offspring, and some can simply be transferred to the genome. Those that appear are dominant, and those that are simply registered in the genome are recessive. Such variability does not bring major changes against the background of the whole species.

Answer: combinative.

Evolution

Evolution in biology is the irreversible historical development of living nature.

It is aimed at the survival of the species. No need to think that evolution is just a complication of the organism, some species have gone down the path of degeneration, that is, simplification, in order to survive.

Biological regression obviously has no options. Those who could not adapt to changing environmental conditions came to regression, which means they died out. Biologists know that it is not the fittest who survive, but the fittest.

Biological progress has three paths, let's start simple:

Adaptation is the main goal. In another way, "adapt" can be said to "adapt".

The next way is idioadaptation.

Idioadaptation is the acquisition of useful traits for life.

Or scientifically: Idioadaptation is the direction of evolution, which consists in the acquisition of new features while maintaining the level of organization of ancestral forms.

Everyone knows what an anteater looks like. He has an elongated muzzle, and all this is necessary in order to get his food, small insects. Such a change in the shape of the muzzle did not make any fundamental changes in the life of anteaters, but it became more convenient for them to eat than from ancestors with a less elongated muzzle.

Aromorphosis - the emergence in the course of evolution of signs that significantly increase the level of organization of living organisms.

For example, the emergence of angiosperms has significantly increased survival rates.

Answer: idioadaptation.

So, we have analyzed one example of tasks from different sections asked in the first task.

Second classification: according to form question asked. Although there are schemes everywhere in the first task, the question can still be posed in different ways.

Question Forms

1. Missing term in the scheme

You just need to enter the missing term in the diagram, as in the tasks above. Most of these questions.

Consider the proposed scheme of evolution directions. Write in the answer the missing term, indicated by a question mark in the diagram.

We discussed this option above, so we write the answer right away.

Answer: idioadaptation.

2. Answer the question from the chart

The scheme is complete, based on your knowledge, you need to answer the question according to the scheme.

Look at the picture for examples of chromosomal mutations. Under the number 3, it indicates a chromosomal rearrangement ... (write down the term in your answer)

There are several types of chromosome rearrangements that you need to know:

Duplication is a type of chromosomal rearrangement in which a portion of a chromosome is doubled.

Deletions are the loss of a portion of a chromosome.

Inversion - a change in the structure of the chromosome, caused by a 180 ° turn of one of its internal sections.

Translocation is the transfer of a part of a chromosome to another.

The third figure clearly shows that there are more sections of chromosomes. The first four sections of the chromosome doubled, they became 9, instead of 5, as it was. This means that a duplication of a part of the chromosome has occurred.

Answer: duplication.

3. Answer to the question about the circuit part

The scheme is complete, but there is a question regarding some part of it:

Consider the proposed scheme for the reaction between amino acids. In response, write down the concept denoting the name of the chemical bond marked in the diagram with a question mark.

This diagram depicts the reaction between two amino acids, which is known from the question. There are peptide bonds between them. You will get to know them in more detail when studying DNA and RNA.

A peptide bond is a chemical bond that occurs between two molecules as a result of a condensation reaction between the carboxyl group (-COOH) of one molecule and the amino group (-NH2) of another molecule, with the release of one molecule of water (H2O).

Answer: peptide or peptide bond.

According to FIPI, the first task is basic, so it is not particularly difficult for a graduate. It covers many topics, but is rather superficial. After studying all the topics, it is better to look at all the available schemes for this assignment, since the answer is not always obvious. And don't forget to read the question carefully, it's not always the same.