Topics for passing the OGE in biology. From work experience

The 2019 state final certification in biology for graduates of the 9th grade of general education institutions is carried out to assess the level of general education training of graduates in this discipline. The tasks test knowledge of the following sections of biology:

The role of biology in the formation of the modern natural science picture of the world, in the practical activities of people.
The cellular structure of organisms as proof of their relationship, the unity of living nature.
Signs of organisms. Unicellular and multicellular organisms. Kingdom of Bacteria. Kingdom of Mushrooms.
Kingdom of Plants.
Animal Kingdom.
General plan of the structure and vital processes. Similarities between humans and animals and differences from them. Reproduction and development of the human body.
Neurohumoral regulation of vital processes of the body.
Support and movement.
Internal environment.
Transport of substances.
Nutrition. Breath.
Metabolism. Selection. Covers of the body.
Sense organs.
Psychology and human behavior.
Compliance with sanitary and hygienic standards and rules healthy image life. Techniques for providing first aid.
Influence environmental factors on organisms.
Ecosystem organization of living nature. Biosphere. The Doctrine of Evolution organic world.

In this section you will find online tests that will help you prepare to take the OGE (GIA) in biology. We wish you success!

The standard OGE test (GIA-9) of the 2019 format in biology contains two parts. The first consists of 28 tasks with a short answer, the second - of 4 tasks with a detailed answer. In this regard, only the first part (i.e., the first 28 tasks) is presented in this test. According to the current exam structure, among these tasks, only 22 questions offer answer options. But for the convenience of passing tests, the site administration decided to offer answer options in all tasks. However, for tasks in which answer options are not provided by the compilers of real test and measurement materials (CMMs), the number of answer options has been significantly increased in order to bring our test as close as possible to what you will have to face in the end school year.

The standard OGE test (GIA-9) of the 2019 format in biology contains two parts. The first consists of 28 tasks with a short answer, the second - of 4 tasks with a detailed answer. In this regard, only the first part (i.e., the first 28 tasks) is presented in this test. According to the current exam structure, among these tasks, only 22 questions offer answer options. But for the convenience of passing tests, the site administration decided to offer answer options in all tasks. However, for tasks in which the compilers of real test and measurement materials (CMMs) do not provide answer options, the number of answer options has been significantly increased in order to bring our test as close as possible to what you will have to face at the end of the school year.

The standard OGE test (GIA-9) of the 2018 format in biology contains two parts. The first consists of 28 tasks with a short answer, the second - of 4 tasks with a detailed answer. In this regard, only the first part (i.e., the first 28 tasks) is presented in this test. According to the current exam structure, among these tasks, only 22 questions offer answer options. But for the convenience of passing tests, the site administration decided to offer answer options in all tasks. However, for tasks in which the compilers of real test and measurement materials (CMMs) do not provide answer options, the number of answer options has been significantly increased in order to bring our test as close as possible to what you will have to face at the end of the school year.

The standard OGE test (GIA-9) of the 2017 format in biology contains two parts. The first consists of 28 tasks with a short answer, the second - of 4 tasks with a detailed answer. In this regard, only the first part (i.e., the first 28 tasks) is presented in this test. According to the current exam structure, among these tasks, only 22 questions offer answer options. But for the convenience of passing tests, the site administration decided to offer answer options in all tasks. However, for tasks in which the compilers of real test and measurement materials (CMMs) do not provide answer options, the number of answer options has been significantly increased in order to bring our test as close as possible to what you will have to face at the end of the school year.

The standard OGE test (GIA-9) of the 2016 format in biology contains two parts. The first consists of 28 tasks with a short answer, the second - of 4 tasks with a detailed answer. In this regard, only the first part (i.e., the first 28 tasks) is presented in this test. According to the current exam structure, among these tasks, only 22 questions offer answer options. But for the convenience of passing tests, the site administration decided to offer answer options in all tasks. However, for tasks in which the compilers of real test and measurement materials (CMMs) do not provide answer options, the number of answer options has been significantly increased in order to bring our test as close as possible to what you will have to face at the end of the school year.

The standard OGE test (GIA-9) of the 2015 format in biology contains two parts. The first consists of 28 tasks with a short answer, the second - of 4 tasks with a detailed answer. In this regard, only the first part (i.e., the first 28 tasks) is presented in this test. According to the current exam structure, among these tasks, only 22 questions offer answer options. But for the convenience of passing tests, the site administration decided to offer answer options in all tasks. However, for tasks in which the compilers of real test and measurement materials (CMMs) do not provide answer options, the number of answer options has been significantly increased in order to bring our test as close as possible to what you will have to face at the end of the school year.

one correct option.

When completing tasks A1-A24, select only one correct option.

Biology. New complete guide to prepare for the OGE. Lerner G.I.

M.: 2018. - 288 p.

The reference book contains all the theoretical material on the biology course and test tasks necessary to prepare for the State Final Certification (OGE) of 9th grade graduates of general education institutions. The theoretical material is presented in a concise and accessible form. Each section is accompanied by examples of test tasks that correspond to the OGE format. They give a comprehensive idea of the types of tasks in the examination paper and their degree of difficulty. At the end of the manual, answers to the tasks are given. The manual can be used by students to prepare for the Unified State Examination and self-control, and by teachers to prepare primary school students for the final certification in biology. The book is addressed to schoolchildren, teachers and methodologists.

Format: pdf

Size: 5.4 MB

Watch, download:drive.google ; Rghost

CONTENT
From the author 5
Part I
1. BIOLOGY AS A SCIENCE
1.1. Basic biological sciences. Methods of biology. The role of biology in the formation of the modern natural science picture of the world, in the practical activities of people. Methods for studying living objects 7
Part II.
2. SIGNS OF LIVING ORGANISMS
2.1. Cellular structure. Chemical composition of the cell. The cellular structure of organisms as proof of their relationship, the unity of living nature. Genes and chromosomes. Disturbances in the structure and functioning of cells are one of the causes of diseases in organisms 15
2.2. Signs of organisms. Heredity and variability are properties of organisms. Unicellular and multicellular organisms. Tissues, organs, organ systems of plants and animals, identifying the variability of organisms. Techniques for growing, propagating and caring for plants and domestic animals 52
Part III.
3. SYSTEM, DIVERSITY AND EVOLUTION OF LIVING NATURE
3.1. Viruses, bacteria, blue-green algae 65
3.2. Kingdom of Mushrooms. general characteristics 69
3.3. Kingdom of Plants. Key Features plant organism 71
3.4. Animal Kingdom. The role of animals in nature and human life 97
3.5. The doctrine of the evolution of the organic world. Charles Darwin is the founder of the doctrine of evolution. Increasing complexity of plants and animals in the process of evolution. Biological diversity as the basis for the stability of the biosphere and the result of evolution 168
Part IV.
4. MAN AND HIS HEALTH
4.1. Fabrics 197
4.2. Structure and functions of the musculoskeletal system 201
4.3. Internal environment of the body. Composition and functions of blood 206
4.4. Structure and functions of the circulatory system 213
4.5. Structure and functions respiratory system 219
4.6. Structure and functions digestive systems s 224
4.7. Metabolism in the body 231
4.8. Structure and functions of the excretory system 236
4.9. Nervous system. General plan of the building. Functions 240
4.10. Structure and functions of the spinal cord 243
4.11. Structure and functions of the brain 245
4.12. Structure and functions of the vegetative nervous system 250
4.13. Higher nervous activity 253
4.14. Sense organs (analyzers). Structure and functions of the organs of vision 259
4.15. Organ of hearing and balance 262
4.16. Olfactory and taste analyzers 265
4.17. Skin, its structure and functions 266
4.18. Endocrine system. Endocrine glands 268
ANSWERS TO SAMPLE TASKS 277

Proposed tutorial consists of 4 sections, including the basic laws of biology with the basics of ecology, plant biology, animal biology, human anatomy and physiology. The manual is written in order to enable schoolchildren who have chosen biology to take the final exam for basic school to quickly repeat school course biology and receive the necessary additional material, knowledge of which is important for further study of biology in high school.
This guide in no way replaces school books and extensive additional benefits. The content of the course is extremely concentrated; a solid assimilation of this material will ensure successful completion exam for basic school. The headings of individual topics are formulated as they are given in the exam codifier.
The first part of each topic provides a summary of the main material in accordance with the examination requirements. Italics indicate terms and concepts that you need to pay attention to when studying the entire biology course. To speed up your work, it is very important to be able to use more advanced reference books and dictionaries. It is best to retell the material you have worked through to yourself or someone close to you.

How can graduates of secondary educational institutions independently prepare for the OGE in biology quickly and effectively? Now everyone who has to take exams, on the results of which the future depends, is puzzled by these questions.

Quite often, schoolchildren cannot decide on future profession. This means that difficulties arise with the choice of subjects, since technical schools, colleges and schools require passing certain subjects for the desired specialty. Students who remain in school must also pass subjects to advance to 10th grade. Russian language and mathematics are considered mandatory, and the rest are optional. So, if you chose biology, then prepare for short term Maybe. First of all, you need to take all the books on the subject for previous years. Better yet, collect notebooks with notes. This will make it faster and easier to learn the material. If you don’t have notes, it doesn’t matter! You can start a notebook and write down important things there.

After all the material has been completed, you can move on to the second stage of preparation.

The most important thing in preparing for exams is a great desire. If it is not there, then there will be no result. Then you need to determine for yourself which method of preparation will be better.

On this moment Special courses are in the lead. They are arranged in the colleges or universities themselves. 3-4 groups of 15-20 people are recruited. This is suitable for those who know the subject with a weak B. It is worth noting that in group classes you may miss important material. There are a lot of people, and it will be physically difficult for the teacher to approach everyone. Therefore, you will have to listen carefully. There are also advantages here. For example, in a group there may be those students who have learned some material well and will be able to explain it later.

Every second person hires tutors. This is the same teacher, but he teaches individually. You don't have to go through all the topics. You can take those that are not clear. Or download the OGE program. And then figure it out.

Self-education is the most effective method. Here the student reads himself, chooses what is useful for himself, learns the most important things and remembers what will be useful in exams. Only this is a method for those who have great willpower and are not lazy. You will have to distribute your time so that you have time left for classes. You need to allocate at least 2 hours a day for self-study. Otherwise there will be no result.

Which preparation method should I choose?

It is now very fashionable to impose preparatory courses and tutors on graduates. Such methods are very expensive. Sometimes like this additional education a lot of money is wasted. And there are also parents who go into debt to educate their children. There is another way out - self-preparation. Firstly, it gives more knowledge, and secondly, it does not require investment.

The best option is to start preparing for exams after finishing 8th grade in the summer. But if it was not possible, then it is advisable to implement the plan in September. In order not to miss anything, you should write down an algorithm of actions for yourself:

Before preparing for the test, you need to take all books, reference books, and encyclopedias on biology. If the librarian refuses to give you textbooks, then you must say that they are needed to prepare for exams. Then you should buy a notebook and take notes for important topics. This will take about three months. Then you need to search the Internet for tables, additional electronic textbooks, brief theory. If possible, it is better to print it out so that the material is always before your eyes. When there is a basic base (it needs to be mastered from September to December), you can begin decision of the OGE.
Now there are many sites for solving the OGE online. This is convenient because you can come in at any time, select an option and decide. Online tests have a time limit, a scoring system for correct and incorrect answers, and a total score. So immediately after solving you can evaluate your knowledge. Don’t be upset if for the first time the system shows low level preparation. On the contrary, you need to start practicing harder. If the specified time is not enough, you can print the tests or buy them at a bookstore. In this case, you can sit and think as much as you want.
The program of the main state exam changes every year. Or amendments are made there. Therefore, it is very important to download a program that indicates which topics to focus on Special attention. It’s better to take it from a tutor or biology teacher. They certainly have it right!
After all the books have been read and more than 80 tests have been passed, you should contact the teacher with a request to check your knowledge. It is better to do this in March. If the teacher says that the result is excellent, then you need to continue in the same spirit. For general development, you can take additional literature on biology, which can also become an integral source of information.
IN social network VKontakte has created special communities for preparing for exams. Several thousand schoolchildren from different corners Russia. And this is another source of information.
If there are those in the class who are taking biology, then you can prepare with them. As they say: “One head is good, but two are better.”

When preparing on your own, you should never give yourself any slack. It is recommended to study daily for 3 hours on weekdays and up to 5 hours on weekends. Of course, it’s hard to sit for so long. Therefore, during the training period you need to take a short rest of 10-15 minutes.

Besides schooling and preparation there are additional things to do - cleaning, walks in the fresh air, entertainment. If possible, it is better to download an audio recording of the topics and listen to free time or before bed.

You need to prepare carefully for the State Examination in Biology, using all possible sources of information. And regular lessons on this subject at school cannot be skipped, despite the fact that the topic is familiar and simple. Repetition of material has never brought harm to anyone.

IN OGE program There will definitely be topics like this:

Biology as a science;
Alive organisms;
Anatomy;
Botany;
Zoology;
Genetics;
Bacteria and viruses;
Animal Kingdom;
Human Physiology;
Evolution of the animal world;
Biosphere;
Ecosystem, etc.

And that's not even half the list! Good preparation takes 4 months or more. Cramming, spurs and hope for luck are unlikely to help. Only knowledge and the ability to apply it in practice will give a positive result.

How to prepare for exams and how difficult it is is clear. But it’s not clear how to make it easier. Doctors strongly recommend the use of Glycine, motherwort tincture, Piracetam and other sedatives. And in order to find out whether a particular medicine is suitable, you need to consult a specialist. The main thing with this question is not to cause panic. It is especially important to reach out Fresh air and eat right.

Preparing for exams requires a lot of effort and time. In order to pass the subject with a good grade, you will have to try. If possible, do not put classes on the back burner. After all, his future depends on how a child prepares. Even if there is only a month left before the exam, there is no need to panic. Nothing is impossible in the world!

THEORETICAL MATERIAL

BIOLOGY AS A SCIENCE. METHODS OF BIOLOGY

Biology - the science of life, its patterns and forms of manifestation, its existence and distribution in time and space. She explores the origins of life and its essence, development, interconnections and diversity. Biology belongs to the natural sciences.

The term “biology” was first used by the German professor of anatomy T. Ruz in 1779. However, it became generally accepted in 1802, after the French naturalist J.-B. began to use it in his works. Lamarck.

Modern biology is a complex science consisting of a number of independent scientific disciplines with their own objects of research.

BIOLOGICAL DISCIPLINES

Botany- plant science,

Zoology- animal science,

Mycology- about mushrooms,

Virology- about viruses,

Microbiology- about bacteria.

Anatomy- a science that studies the internal structure of organisms (individual organs, tissues). Plant anatomy studies the structure of plants, animal anatomy studies the structure of animals.

Morphology- the science that studies external structure organisms

Physiology- a science that studies the vital processes of the body and the functions of individual organs.

Hygiene- the science of preserving and strengthening human health.

Cytology- cell science.

Histology- tissue science.

Taxonomy- the science of classifying living organisms. Classification is the division of organisms into groups (species, genus, families, etc.) based on structural features, origin, development, etc.

Paleontology- a science that studies the fossil remains (imprints, fossils, etc.) of organisms.

Embryology- the science that studies the individual (embryo) development of organisms.

Ecology- a science that studies the relationships of organisms with each other and with the environment.

Ethology- the science of animal behavior.

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

Selection- science of breeding new and improving existing breeds of domestic animals, varieties cultivated plants and strains of bacteria and fungi.

Evolutionary doctrine- studies issues of origin and laws historical development life on Earth.

Anthropology- the science of the emergence and development of man.

Cell engineering- a branch of science dealing with the production of hybrid cells. An example is the hybridization of cancer cells and lymphocytes, the fusion of protoplasts of different plant cells, and cloning.

Genetic Engineering- a branch of science that deals with the production of hybrid DNA or RNA molecules. If cell engineering works at the cellular level, then genetic engineering works at the molecular level. In this case, specialists “transplant” the genes of one organism to another. One of the results genetic engineering is the production of genetically modified organisms (GMOs).

Bionics- a direction in science that searches for opportunities to apply the principles of organization, properties and structures of living nature in technical devices.

Biotechnology- a discipline that studies the possibilities of using organisms or biological processes to produce substances, needed by a person. Typically, biotechnological processes use bacteria and fungi.

GENERAL METHODS OF BIOLOGY

A method is a way of understanding reality.

1. Observation and description.

2.Measurement

3. Comparison

4. Experiment or experience

5. Simulation

6. Historical.

STEPS scientific research

Held observation over an object or phenomenon

based on the data obtained, it is put forward hypothesis

scientific experiment(with control experience)

a hypothesis tested during an experiment can be called
theory or by law

PROPERTIES OF LIVING

Metabolism and energy flow- most important property alive. All living organisms absorb the substances they need from external environment and release waste products into it.

Unity chemical composition. Among chemical elements In living organisms, carbon, oxygen, hydrogen and nitrogen predominate. In addition, the most important feature of living organisms is the presence of organic substances: fats, carbohydrates, proteins and nucleic acids.

Cellular structure. All organisms are made up of cells. Only viruses have a non-cellular structure, but they also show signs of being alive only after entering the host cell.

Irritability- the body’s ability to respond to external or internal influences.

Self-reproduction. All living organisms are capable of reproduction, that is, the reproduction of their own kind. Reproduction of organisms occurs in accordance with the genetic program recorded in DNA molecules.

Heredity and variability.

Heredity is the ability of organisms to pass on their characteristics to their descendants. Heredity ensures continuity of life. Variability is the ability of organisms to acquire new characteristics in the process of their development. Hereditary variability is important factor evolution.

Growth and development.

Growth - quantitative changes (for example, increase in mass).

Development - qualitative changes (for example, the formation of organ systems, flowering and fruiting).

Self-regulation - the ability of organisms to maintain the constancy of their chemical composition and vital processes - homeostasis.

Adaptation

Rhythm - periodic changes in the intensity of physiological functions with different periods of fluctuations (daily, seasonal rhythms). (For example, photoperiodism is the body’s reaction to the length of daylight hours).

Levels of life organization

Number level	Name	What is represented by
	Biosphere	The totality of all ecosystems planets
	Ecosystem (biogeocenotic)	System of different populations species in their relationship with each other and the environment	Savannah, tundra
	Population- species	The totality of populations forming species	White bears, blue whales
	Organismal	The body as an integral system	Bacteria, monkey
	Cellular	Cell and its structural components	Red blood cells, mitochondria, chloroplasts
	Molecular	Organic and inorganic substances	Proteins, carbohydrates; Water, salt ions

Test tasks in OGE format

What science studies varietal diversity plants?

1)physiology 2)systematics 3)ecology 4)selection

2. You can find out whether light is necessary for the formation of starch in leaves using

1) descriptions of plant organs 2) comparisons of different plants natural areas

3) observations of plant growth 4) photosynthesis experiment

3. In what area of biology was cell theory developed?

1) virology 2) cytology 3) anatomy 4) embryology

4. To separate cell organelles by density, you will choose a method

1) observation 2) chromatography 3) centrifugation 4) evaporation

5. The photograph shows a model of a DNA fragment. What method allowed scientists to create such a three-dimensional image of a molecule?

1) classification 2) experiment 3) observation 4) modeling

6. The photo shows a ball-and-stick DNA fragment. What method allowed scientists to create such a three-dimensional image of a molecule?

classification 2) experiment 3) observation 4) modeling

7. Application of which scientific method illustrates the plot of the painting “Pulse” by the Dutch artist J. Steen, painted in the mid-17th century?

1) modeling 2) measurement 3) experiment 4) observation

8. Study the graph reflecting the process of growth and development of the insect.

Determine the length of the insect on the 30th day of its development.

1) 3,4 2) 2,8 3) 2,5 4) 2,0

9. Which of the following scientists is considered the creator of the doctrine of evolution?

1) I.I. Mechnikov 2) L. Pasteur 3) Ch. Darwin 4) I.P. Pavlova

10. What science studies the varietal diversity of plants?

1) physiology 2) taxonomy 3) ecology 4) selection

11. Select a pair of animals whose experiments have led to major discoveries in animal and human physiology.

1) horse and cow 2) bee and butterfly 3) dog and frog 4) lizard and dove

12. In what area of biology was cell theory developed?

1) virology 2) cytology 3) anatomy 4) embryology

13. You can accurately determine the degree of influence of fertilizers on plant growth using the method

1) experiment 2) modeling 3) analysis 4) observation

14. An example of the application of an experimental research method is

1) description of the structure of a new plant organism

2) comparison of two micropreparations with various fabrics

3) counting a person’s pulse before and after exercise

4) formulating a position based on the facts obtained

15. A microbiologist wanted to find out how quickly one type of bacteria multiplies in different nutrient media. He took two flasks, filled them halfway with different nutrient media and placed approximately the same number of bacteria in them. Every 20 minutes he removed samples and counted the number of bacteria in them. The data from his research are reflected in the table.

Study the table “Change in the rate of reproduction of bacteria over a certain time” and answer the questions.

Change in the rate of bacterial reproduction over a certain time

Time after introduction of bacteria into the culture, min.	Number of bacteria in flask 1	Number of bacteria in flask 2

1) How many bacteria did the scientist put in each flask at the very beginning of the experiment?

2) How did the rate of bacterial reproduction change during the experiment in each flask?

3) How can we explain the results obtained?

Literature

Kamensky A.A., Kriksunov E.A., Pasechnik V.V. Biology. General biology 9th grade: textbook. For educational institution. M.: Bustard, 2013.

Zayats R.G., Rachkovskaya I.V., Butilovsky V.E., Davydov V.V. Biology for applicants: questions, answers, tests, tasks. - Minsk: Unipress, 2011. - 768 p.

“I will solve the OGE”: biology. Dmitry Gushchin's training system [Electronic resource] - URL: http:// oge.sdamgia.ru

Cell structure, cell division, protein biosynthesis. Reproduction. Development -

Ontogenesis

Properties of living structures:

1) self-renewal. Metabolism is based on the interconnected processes of assimilation (anabolism, synthesis, formation of new substances) and dissimilation (catabolism, decay);

2) self-reproduction. Nucleic acids are capable of storing, transmitting and reproducing hereditary information, as well as implementing it through protein synthesis. The information stored on DNA is transferred to the protein molecule using RNA molecules;

3) self-regulation. Based on the totality of flows of matter, energy and information through a living organism;

4) irritability. Associated with the transfer of information from the outside to any biological system and reflects the reaction of this system to external stimulus

5) maintaining homeostasis - the relative dynamic constancy of the internal environment of the body

7) adaptation - the ability of a living organism to constantly adapt to changing conditions of existence in environment;

8) reproduction (reproduction

9) heredity. Thanks to heredity, traits that ensure adaptation to the environment are passed on from generation to generation;

10) variability - due to variability living system acquires characteristics that were previously unusual for her

11) individual development (ontogenesis process). During this process, such a property as the ability to grow appears, which is expressed in an increase in body weight and its size;

12) phylogenetic development. Based on progressive reproduction, heredity, struggle for existence and selection. As a result of evolution, it appeared great amount species;

13) discreteness (discontinuity) and at the same time integrity. Each organism, in turn, is also discrete, since it consists of a collection of organs, tissues and cells.

Squirrels are polymers whose monomers are amino acids Functions of proteins: 1) protective; 2) structural; 3) motor; 4) storage; 5) transport; 6) receptor; 7) regulatory; 8) hormone proteins participate in humoral regulation; 9) enzyme proteins catalyze everything chemical reactions in the body; 10) energy.

Carbohydrates - these are mono- and polymers, which include carbon, hydrogen and oxygen. The functions of carbohydrates are: 1) energy; 2) structural; 3) storage.

Fats (lipids) can be simple or complex. Simple lipid molecules consist of the trihydric alcohol glycerol and three fatty acid residues. Complex lipids are compounds of simple lipids with proteins and carbohydrates. Functions of lipids: 1) energy; 2) structural; 3) storage; 4) protective; 5) regulatory; 6) heat-insulating.

The ATP (adenosine triphosphoric acid) molecule is formed in mitochondria and is the main source of energy.

5. Protein biosynthesis. Genetic code

There are 2 types of nucleic acids - deoxyribonucleic acid (DNA) and ribonucleic acid (RNA).

DNA is a helix consisting of two complementary polynucleotide chains twisted to the right. Two chains of nucleotides are connected to each other through nitrogenous bases according to the principle of complementarity: two hydrogen bonds arise between adenine and thymine, and three between guanine and cytosine.

Functions of DNA:

1) ensures the preservation and transmission of genetic information from cell to cell and from organism to organism (replication);

2) regulates all processes in the cell, providing the ability for transcription followed by translation.

Replication occurs during the synthetic period of interphase of mitosis. The replicase enzyme moves between the two strands of the DNA helix and breaks hydrogen bonds between nitrogenous bases. Then, using the enzyme DNA polymerase, the nucleotides of the daughter chains are added to each of the chains according to the principle of complementarity. As a result of replication, two identical DNA molecules are formed. The amount of DNA in the cell doubles. This method of DNA doubling is called semi-conservative, since each new DNA molecule contains one “old” and one newly synthesized polynucleotide chain.

RNA is a single-stranded polymer. There are 3 types of RNA.

1. Messenger RNA (i-RNA) is located in the nucleus and cytoplasm of the cell and performs the function of transferring hereditary information from the nucleus to the cytoplasm of the cell.

2. Transfer RNA (tRNA) is also found in the nucleus and cytoplasm of the cell and delivers amino acids to ribosomes during the process of translation - protein biosynthesis.

3. Ribosomal RNA (r-RNA) is found in the nucleolus and ribosomes of the cell.

Protein biosynthesis occurs in several stages.

1. Transcription is the process of synthesis of mRNA on a DNA template.

2. Then processing occurs - maturation of the RNA molecule.

Transcription occurs in the cell nucleus. Then the mature mRNA enters the cytoplasm through pores in the nuclear membrane, and translation begins.

3. Translation is the process of protein synthesis on a matrix and RNA.

Genetic code It is a system of encoding the amino acid sequence of a protein as a specific sequence of nucleotides in DNA and RNA.

A unit of genetic code (codon) is a triplet of nucleotides in DNA or RNA that codes for one amino acid.

In total, the genetic code includes 64 codons, of which 61 are coding and 3 are non-coding (terminator codons).

Terminator codons in mRNA: UAA, UAG, UGA, in DNA: ATT, ATC, ACT.

The genetic code has characteristic properties.

1. Universality - the code is the same for all organisms.

2. Specificity - each codon encodes only one amino acid.

Prenuclear prokaryotes do not have a typical nucleus. These include bacteria and blue-green algae.

Prokaryotes arose in Archean era. These are very small cells ranging in size from 0.1 to 10 microns.

A typical bacterial cell is surrounded on the outside cell wall, the basis of which is the substance murein and determines the shape of the bacterial cell. On top of the cell wall there is a mucous capsule that performs protective function.

Below the cell wall is the plasma membrane. The entire cell inside is filled with cytoplasm, which consists of a liquid part (hyaloplasm, or matrix), organelles and inclusions.

Hereditary apparatus: one large “naked” DNA molecule, devoid of protective proteins, closed in a ring - a nucleoid. The hyaloplasm of some bacteria also contains short circular DNA molecules that are not associated with a chromosome or nucleoid - plasmids.

There are few membrane organelles in prokaryotic cells. There are mesosomes - internal outgrowths of the plasma membrane, which are considered the functional equivalent of eukaryotic mitochondria. In autotrophic prokaryotes, lamellae and lamesomes are found - photosynthetic membranes. They contain the pigments chlorophyll and phycocyanin.

Some bacteria have organelles of movement - flagella. Bacteria have recognition organelles called pili (fimbriae).

Chromatin in the form of clumps is scattered in the nucleoplasm and is an interphase form of chromosome existence.

Plant cells also contain chloroplasts, in which photosynthesis occurs.

Functions and structure of the cytoplasmic membrane and cell nucleus

The elementary membrane consists of a bilayer of lipids in complex with proteins. Each fat molecule has a polar hydrophilic head and a non-polar hydrophobic tail. In this case, the molecules are oriented so that the heads face outward and inside the cell, and the non-polar tails face inside the membrane itself. This achieves selective permeability for substances entering the cell.

Functions of membrane proteins: receptor, structural, enzymatic, transport

1) barrier (delimitation of the internal contents of the cell);

2) structural (giving a certain shape to cells);

3) protective (due to selective permeability);

4) regulatory (regulation of selective permeability for various substances);

5) adhesive function (all cells are connected to each other through specific contacts (tight and loose);

6) receptor;

The cell nucleus consists of a membrane, nuclear sap, nucleolus and chromatin . Nuclear envelope consists of two membranes. The main functions of the nuclear membrane: separation of genetic material (chromosomes) from the cytoplasm, as well as regulation of bilateral relationships between the nucleus and the cytoplasm.

The nuclear envelope is permeated with pores, which have a diameter of about 90 nm.

The basis of nuclear juice (matrix, nucleoplasm) is proteins. The juice forms the internal environment of the kernel, plays important role in the functioning of the genetic material of cells.

Nucleolus is the structure where the formation and maturation of ribosomal RNA (rRNA) occurs. rRNA genes occupy certain regions of several chromosomes, where nucleolar organizers are formed, in the area of which the nucleoli themselves are formed.

Chromatin consists mainly of DNA strands (40% of the chromosome mass) and proteins (about 60%), which together form a nucleoprotein complex.

8. Structure and functions of mitochondria and lysosomes

Mitochondria- these are permanent membrane organelles of a round or rod-shaped (often branching) shape. Main functions of mitochondria:

1) play the role of energy stations of cells;

2) store hereditary material in the form of mitochondrial DNA.

Mitochondria have two membranes: outer (smooth) and inner (forming outgrowths - leaf-shaped (cristae) and tubular (tubules)).

Lysosomes- these are bubbles with a diameter of 200-400 microns. (usually). They have a single membrane shell. The main function is intracellular digestion of various chemical compounds and cellular structures.

Endoplasmic reticulum (ER)- a system of communicating or separate tubular channels and flattened cisterns located throughout the cytoplasm of the cell. ER channels can connect to the surface or nuclear membranes and contact the Golgi complex. Rough XPS Ribosomes are located on the channels of the rough ER in the form of polysomes. Protein synthesis occurs here Smooth XPS There are no ribosomes on the smooth ER membranes. The synthesis of fats and similar substances (for example, steroid hormones), as well as carbohydrates, takes place here. Movement also occurs along the channels of the smooth ER. finished material to the place of its packaging into granules (in the zone of the Golgi complex). Golgi complex gives rise to primary lysosomes.

10. Structure and functions of non-membrane cell structures

Ribosome It is a round ribonucleoprotein particle. Its diameter is 20-30 nm. The ribosome consists of large and small subunits. Cells of all animals, some fungi, algae, higher plants characterized by the presence of a cell center. Cell center usually located next to the nucleus. It consists of two centrioles, located mutually perpendicular. From the centrioles of the cell center, during cell division, filaments of the spindle are formed. Centrioles polarize the process of cell division, thereby achieving uniform separation of sister chromosomes (chromatids) in anaphase of mitosis. Inside the cell is cytoplasm. It consists of a liquid part - hyaloplasm (matrix), organelles and cytoplasmic inclusions. Hyaloplasma- the main substance of the cytoplasm. Inclusions are relatively unstable components of the cytoplasm. They are distinguished: 1) reserve nutrients that are used by the cell itself during periods of insufficient intake nutrients from the outside; 2) products that must be released from the cell;

Many viruses are the causative agents of diseases such as AIDS, rubella measles, mumps, chickenpox and smallpox. Mature virus particles are called virions. In fact, they are a genome covered with a protein shell on top. This shell is the capsid.

Gametes Egg- a large, immobile cell with a supply of nutrients. The size of a female egg is 150-170 microns Sperm is a male reproductive cell (gamete). He has the ability to move. The dimensions of the sperm are microscopic: the length of this cell in humans is 50-70 microns

The sperm has a head, a neck, an intermediate section and a tail in the form of a flagellum. Almost the entire head is filled with a nucleus, which carries hereditary material in the form of chromatin. At the anterior end of the head (at its apex) there is an acrosome, which is a modified Golgi complex.

Fertilization- This is the process of fusion of germ cells. As a result of fertilization, a diploid cell is formed - a zygote. Biological role asexual reproduction Maintaining fitness enhances the importance of stabilizing natural selection; ensures rapid reproduction rates; used in practical selection. Forms of asexual reproduction

In unicellular organisms, the following forms of asexual reproduction are distinguished: division, endogony, schizogony and budding, sporulation.

Division characteristic of amoeba, ciliates, flagellates. First, mitotic division of the nucleus occurs, then the cytoplasm is divided in half by an increasingly deepening constriction. In this case, daughter cells receive approximately the same amount of cytoplasm and organelles.

Endogony(internal budding) is characteristic of toxoplasma. When two daughters are formed, the mother gives only two offspring. But there may be internal multiple budding, which will lead to schizogony.

It is found in sporozoans (malarial plasmodium), etc. Multiple divisions of the nucleus occur without cytokinesis. From one cell many daughter cells are formed.

Budding(in bacteria, yeasts, etc.).

Sporulation(in higher spore plants: mosses, ferns, mosses, horsetails, algae).. Vegetative a form of reproduction by part of the mother's body.

regeneration- restoration of lost tissues and body parts (in annelids, lizards, salamanders). Sexual reproduction - fertilization, Parthenogenesis - daughter organisms develop from unfertilized eggs. The meaning of parthenogenesis:

1) reproduction is possible with rare contacts of opposite-sex individuals; 2) the population size increases sharply; 3) occurs in populations with high mortality during one season.

Cell division. Mitosis phases:

1) prophase. The centrioles of the cell center divide and move to opposite poles of the cell. A fission spindle is formed from microtubules, which connects the centrioles of different poles. At the beginning of prophase, the nucleus and nucleoli are still visible in the cell; by the end of this phase, the nuclear envelope is divided into separate fragments. Chromosomes begin to condense: they curl, thicken, and become visible under a light microscope. In the cytoplasm, the number of rough ER structures decreases, the number of polysomes sharply decreases;

2) metaphase. The formation of the fission spindle ends. Condensed chromosomes line up along the equator of the cell, forming a metaphase plate. Spindle microtubules are attached to the centromeres, or kinetochores (primary constrictions), of each chromosome. After this, each chromosome is longitudinally split into two chromatids (daughter chromosomes), which are connected only at the centromere;

3) anaphase. The connection between the daughter chromosomes is broken, and they begin to move to opposite poles of the cell. At the end of anaphase, each pole has a diploid set of chromosomes. Chromosomes begin to decondense and unwind, becoming thinner and longer;

4) telophase. Chromosomes are completely despiralized, the structure of the nucleoli and interphase nucleus is restored, and the nuclear membrane is assembled. The fission spindle is destroyed. Cytokinesis (cytoplasm division) occurs. The formation of a constriction begins in the equatorial plane, which completely divides the mother cell into two daughter cells.

1. Amitosis- This is direct fission of the nucleus. At the same time, the morphology of the nucleus is preserved, the nucleolus and nuclear membrane are visible. The chromosomes are not visible and are not evenly distributed. The nucleus is divided into two relatively equal parts without the formation of a mitotic apparatus. Meiosis is a type of cell division in which the number of chromosomes is halved and Stages of meiosis The first division of meiosis (reduction) leads to the formation of haploid cells from diploid cells. In prophase I, as in mitosis, chromosome spiralization occurs. At the same time, homologous chromosomes come together with their identical sections (conjugate), forming bivalents. Before entering meiosis, each chromosome has doubled genetic material and consists of two chromatids, so the bivalent contains 4 strands of DNA. In the process of further spiralization, crossing over can occur - the crossing of homologous chromosomes, accompanied by the exchange of corresponding sections between their chromatids. In metaphase I, the formation of the division spindle is completed, the threads of which are attached to the centromeres of chromosomes, united into bivalents in such a way that only one thread goes from each centromere to one of the poles of the cell. In anaphase I, the chromosomes diverge to the poles of the cell, with each pole having a haploid set of chromosomes, consisting of two chromatids. In telophase I, the nuclear envelope is restored, after which the mother cell divides into two daughter cells.

The second division of meiosis begins immediately after the first and is similar to mitosis, but the cells entering it carry a haploid set of chromosomes. Prophase II is very short in time. This is followed by metaphase II, during which the chromosomes are located in the equatorial plane, and a spindle is formed. In anaphase II, centromeres separate and each chromatid becomes an independent chromosome. The daughter chromosomes separated from each other are directed to the division poles. In telo-phase II, cell division occurs, in which 4 daughter haploid cells are formed from two haploid cells.

Thus, as a result of meiosis, four cells with a haploid set of chromosomes are formed from one diploid cell. The biological significance of meiosis 1) is the main stage of gametogenesis; 2) ensures the transfer of genetic information from organism to organism during sexual reproduction; 3) daughter cells are not genetically identical to the mother and between themselves. Gametogenesis is the process of formation of germ cells. Ontogenesis- it's a process individual development individuals from the moment of formation of the zygote during sexual reproduction until the end of life. The first stage of embryonic development is splitting up. In this case, first 2 cells are formed from the zygote through mitotic division, then 4, 8, etc. The resulting cells are called blastomeres, and the embryo at this stage of development is called a blastula. At the same time, the total mass and volume almost do not increase, Gastrulation. At this time, blastomeres, which continue to rapidly divide, acquire motor activity and move relative to each other, forming layers of cells - germ layers from the ectoderm, skin and its derivatives develop. The endoderm gives rise to the organs of the respiratory and digestive systems. Muscle, cartilage and bone tissue, organs of the circulatory and excretory systems are formed from the mesoderm.

Dissimilation, or energetic exchange is a set of reactions of the breakdown of high-molecular compounds, which are accompanied by the release and storage of energy.
Stage 1 Preparatory:
occurs in lysosomes or in food. The system is complex organic matter split into simpler ones
(e.g. proteins to amino acids)
At this stage, ATP is not synthesized
Stage 2 Oxygen-free (glycolysis):
occurs in the cytoplasm
glucose to 2 molecules of pyruvic acid
energy reserve in the form of 2 ATP molecules

Stage 3 Oxygen:
occurs in mitochondria
oxidation of pyruvic acid to CO2 and H2O
36 mol ATP is formed

Topics for passing the OGE in biology. From work experience

Biology. New complete guide to prepare for the OGE. Lerner G.I.

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