Metabolisms occurring in human cells. Metabolisms occurring in human cells The breakdown of macromolecular compounds in the cell is carried out
1. The whole set of chemical reactions in a cell is called
1) photosynthesis
2) chemosynthesis
3) fermentation
4) metabolism
2. Oxidation organic matter with the release of energy in the cell occurs in the process
allocation
photosynthesis
biosynthesis
3. Exchange of substances between the cell and environment regulated
1) plasma membrane
2) endoplasmic reticulum
3) nuclear membrane
4) cytoplasm
4. In the process of energy metabolism, in contrast to plastic,
ATP energy expenditure
storage of energy in ATP
providing cells with proteins and lipids
providing cells with carbohydrates and nucleic acids
5. The reactions of synthesis and breakdown of organic substances in cells cannot occur without the participation of
1) hemoglobin
2) hormones
3) enzymes
4) pigments
6. What characterizes the processes of biological oxidation?
high speed and rapid release of thermal energy
participation of enzymes and gradation
the participation of hormones and low speed
hydrolysis of polymers
7. As a result of what process lipids are oxidized?
1) energy metabolism
2) plastic exchange
3) photosynthesis
4) chemosynthesis
8. The energy used by a person in the process of life is released in the cells
during the oxidation of organic substances
in the process of synthesis of complex organic substances from simple ones
in the formation of organic substances from inorganic
transporting nutrients through the blood
9. Energy metabolism is a set of reactions
1) protein synthesis on the ribosome
2) the entry of substances into the cell
3) breakdown of organic substances and ATP synthesis
4) the formation of glucose from carbon dioxide and water
10. The importance of energy metabolism in cellular metabolism lies in the fact that it provides synthesis reactions
1) energy contained in ATP molecules
2) organic substances
3) enzymes
4) minerals
11. The energy contained in the high-energy bonds of ATP molecules is used in the process
1) protein biosynthesis
2) the preparatory stage of energy metabolism
3) oxygen stage of energy metabolism
4) synthesis of ATP molecules from ADP
12. The greatest amount of energy is released during the splitting of molecules
1) proteins to amino acids
2) polysaccharides to monosaccharides
3) fats to glycerol and fatty acids
4) glucose to carbon dioxide and water
13. Synthesis of ATP molecules occurs
1) in the process of protein biosynthesis
2) in the process of starch synthesis from glucose
3) at the preparatory stage of energy metabolism
4) at the oxygen stage of energy metabolism
14. Hydrolytic cleavage of macromolecular substances in the cell at the preparatory stage of energy metabolism occurs in
1) lysosomes
2) cytoplasm
3) endoplasmic reticulum
4) mitochondria
15. The process of energy metabolism begins with
glucose synthesis
breakdown of polysaccharides
fructose synthesis
PVC oxidation
16. At the preparatory stage of energy exchange
1) proteins are synthesized from amino acids
2) biopolymers are broken down to monomers
3) glucose is broken down to pyruvic acid
4) lipids are synthesized from glycerol and fatty acids
17. The breakdown of lipids to glycerol and fatty acids occurs in
preparatory stage of energy metabolism
glycolysis process
oxygen stage of energy metabolism
the course of plastic exchange
18. Final products preparatory phase energy metabolism
1) carbon dioxide and water
2) glucose and amino acids
3) proteins, fats
4) ADP, ATP
19. Enzymatic breakdown of glucose without the participation of oxygen is
preparatory stage of energy metabolism
plastic exchange
glycolysis
biological oxidation
20. At what stage of energy metabolism are 2 ATP molecules synthesized?
1) glycolysis
2) preparatory stage
3) oxygen stage
4) the entry of substances into the cell
21. How many ATP molecules are stored during glycolysis?
22. The anaerobic stage of glycolysis proceeds in
digestive tube
cytoplasm
mitochondria
23. In the process of glycolysis in human muscles, under heavy loads, accumulates
24. In the process of breathing, energy can move from
chemical to thermal
mechanical to thermal
thermal to chemical
thermal to mechanical
25. When breathing, the human body receives energy due to
oxidation of organic substances
breakdown of minerals
converting carbohydrates into fats
synthesis of proteins and fats
26. At the oxygen stage of energy metabolism, molecules are oxidized
2) lipids
3) polysaccharides
4) pyruvic acid
27. As a result of the oxygen stage of energy metabolism, molecules are synthesized in cells
2) glucose
4) enzymes
28. In mitochondria, hydrogen atoms donate electrons, while energy is used for synthesis
carbohydrates
29. The synthesis of 36 ATP molecules occurs in the process
1) plastic exchange
2) protein biosynthesis
3) the preparatory stage of energy metabolism
4) oxygen stage of energy metabolism
30. 38 ATP molecules are synthesized in the cell during
glucose oxidation
fermentation
photosynthesis
chemosynthesis
31. In what organelles of human cells does the oxidation of pyruvic acid occur with the release of energy?
1) ribosomes
2) nucleolus
3) chromosomes
4) mitochondria
32. Oxidative phosphorylation occurs on
outer membranes of mitochondria
inner membranes of mitochondria
outer membranes of chloroplasts
inner membranes of chloroplasts
33. As a result of energy metabolism reactions, final products are formed
1) carbohydrates and oxygen
2) carbon dioxide and water
3) amino acids
4) pyruvic acid
34. A plant cell, like an animal cell, receives energy in the process
1) oxidation of organic substances
2) protein biosynthesis
3) lipid synthesis
4) nucleic acid synthesis
35. A set of reactions for the synthesis of organic substances using the energy contained in ATP molecules is called
1) energy exchange
2) photosynthesis
3) plastic exchange
4) denaturation
36. Plastic metabolism in a cell is characterized by
1) the breakdown of organic substances with the release of energy
2) the formation of organic substances with the accumulation of energy in them
3) absorption of nutrients into the blood
4) digestion of food with the formation of soluble substances
37. What molecules are synthesized in cells during plastic metabolism?
4) inorganic substances
38. The value of plastic metabolism is to provide the body
1) organic substances
2) minerals
3) energy
4) vitamins
39. The peculiarities of metabolism in plants in comparison with animals is that in their cells occurs
1) chemosynthesis
2) energy exchange
3) photosynthesis
4) protein biosynthesis
40. Common between the processes of photosynthesis and respiration is
formation of organic substances from inorganic
ATP formation
release of oxygen
release of carbon dioxide
41. Photosynthesis, unlike protein biosynthesis, occurs in cells
1) any organism
42. All living organisms in the process of life use energy that is stored in organic substances created from inorganic
1) animals
2) mushrooms
3) plants
4) viruses
43. Photosynthesis should be considered as the most important link in the carbon cycle in the biosphere, since during its
Plants take carbon from non-living things into living things.
Plants release oxygen into the atmosphere
organisms release carbon dioxide during respiration
industrial production replenishes the atmosphere with carbon dioxide
44. The cosmic role of plants on Earth is
use of solar energy in the process of photosynthesis
absorption of minerals from the environment
absorption of carbon dioxide from the environment
release of oxygen during photosynthesis
45. Plants are the mediator between the Sun and living organisms on Earth, since their cells contain
shell and cell membrane
cytoplasm and vacuoles
mitochondria that synthesize ATP
chloroplasts that carry out photosynthesis
46. What processes occur during photosynthesis?
1) synthesis of carbohydrates and release of oxygen
2) evaporation of water and absorption of oxygen
3) gas exchange and lipid synthesis
4) carbon dioxide release and protein synthesis
47. In the process of plant photosynthesis
1) provide themselves with organic substances
2) oxidize complex organic substances to simple ones
3) absorb minerals roots from the soil
4) consume the energy of organic substances
48. Chlorophyll in chloroplasts of plant cells
1) communicates between organelles
2) accelerates the reactions of energy metabolism
3) absorbs light energy during photosynthesis
4) carries out the oxidation of organic substances in the process of respiration
49. Under the influence of energy sunlight an electron moves to a higher energy level in a molecule
2) glucose
3) chlorophyll
4) carbon dioxide
50. Which of the above processes occurs in the light phase of photosynthesis?
1) reduction of carbon dioxide with hydrogen to glucose
2) synthesis of ATP molecules
3) oxidation of organic substances
4) splitting of ATP molecules to AMP with the release of energy
51. Which of the following conditions is necessary for the synthesis of ATP and the reduction of NADP during photosynthesis?
the presence of glucose
sunlight
lack of lighting
oxygen
52. As a result of what process oxygen is formed during photosynthesis?
1) photolysis of water
2) decomposition of carbon dioxide
3) reduction of carbon dioxide to glucose
4) ATP synthesis
53. Photolysis of water occurs in a cell in
mitochondria
lysosomes
chloroplasts
54. Photolysis of water is initiated during photosynthesis by energy
1) solar
3) thermal
4) mechanical
55. What process does NOT occur during the light phase of photosynthesis?
1) ATP synthesis
2) synthesis of NADP-H 2
3) photolysis of water
4) glucose synthesis
56. Dark phase reactions of photosynthesis involve
CO 2 , ATP and NADP-H 2
carbon monoxide, atomic oxygen, NADP +
O 2, chlorophyll, DNA
water, hydrogen, tRNA
57. What processes occur in the dark phase of photosynthesis?
1) photolysis of water molecules
2) synthesis of ATP molecules
3) reduction of carbon dioxide with hydrogen to glucose
4) excitation of electrons in a chlorophyll molecule
58. The similarity of chemosynthesis and photosynthesis lies in the fact that in both processes
organic matter is formed from inorganic
the same metabolic products are formed
59. The similarity of chemosynthesis and photosynthesis lies in the fact that in both processes
solar energy is used to form organic substances
the formation of organic substances uses the energy of oxidation of inorganic substances
carbon dioxide is used as a source of carbon
the end product, oxygen, is released into the atmosphere
60. In the process of chemosynthesis, unlike photosynthesis,
1) organic substances are formed from inorganic
2) the energy of oxidation of inorganic substances is used
3) organic substances are broken down into inorganic
4) the source of carbon is carbon dioxide
61. What substance is a source of hydrogen for the reduction of carbon dioxide in the process of photosynthesis?
1) hydrochloric acid
2) carbonic acid
4) glucose
62. Photosynthesis first appeared in
cyanobacteria
psilophytes
unicellular algae
multicellular algae
63. In the life of what organisms do chloroplasts play an important role?
nodule bacteria
hat mushrooms
unicellular plants
invertebrates
64. Of the following organisms, photosynthesis is capable of
amoeba common
infusoria slipper
trypanosome
The cell constantly exchanges substances and energy with the environment. Metabolism (metabolism)- the main property of living organisms. At the cellular level, metabolism includes two processes: assimilation (anabolism) and dissimilation (catabolism). These processes occur simultaneously in the cell.
Assimilation(plastic exchange) - a set of reactions of biological synthesis. From simple substances entering the cell from the outside, substances characteristic of this cell are formed. The synthesis of substances in the cell occurs using the energy contained in the ATP molecules.
Dissimilation (energy metabolism)- a set of reactions of splitting substances. During the breakdown of macromolecular compounds, the energy necessary for biosynthesis reactions is released.
According to the type of assimilation, organisms can be autotrophic, heterotrophic and mixotrophic.
Photosynthesis and chemosynthesis- two forms of plastic exchange. Photosynthesis- the process of formation of organic substances from carbon dioxide and water in the light with the participation of photosynthetic pigments.
Chemosynthesis - a method of autotrophic nutrition, in which oxidation reactions serve as an energy source for the synthesis of organic substances from CO2 inorganic compounds
Generally, all organisms capable of inorganic substances synthesize organic, i.e. Organisms capable of photosynthesis and chemosynthesis are classified as autotrophs. Plants and some microorganisms are traditionally classified as autotrophs.
The main substance involved in the multi-stage process of photosynthesis is chlorophyll. It is it that transforms solar energy into chemical energy.
Light phase of photosynthesis:
(carried out on thylakoid membranes)
Light, hitting the chlorophyll molecule, is absorbed by it and brings it into an excited state - an electron that is part of the molecule, having absorbed the energy of light, goes to a higher energy level and participates in the synthesis processes;
Under the action of light, the splitting (photolysis) of water also occurs: 
protons (with the help of electrons) turn into hydrogen atoms and are spent on the synthesis of carbohydrates;
ATP is synthesized (energy)
Dark phase of photosynthesis(occurs in the stroma of chloroplasts)
the actual synthesis of glucose and the release of oxygen
note: this phase is called dark not because it takes place at night - glucose synthesis occurs, in general, around the clock, but light energy is no longer needed for the dark phase.
20. Metabolism in the cell. dissimilation process. The main stages of energy metabolism.
In all cells of living organisms, the processes of metabolism and energy are continuously going on - this is metabolism. If we consider this process in more detail, then this permanent processes formation and decay substances and absorption and excretion energy.
Metabolism in the cell:
The process of synthesis of substances = plastic metabolism = assimilation = anabolism
To build something, you need to spend energy - this process goes with the absorption of energy.
splitting process = energy metabolism= dissimilation=catabolism
This is a process in which complex substances decompose into simple ones, while energy is released.
Basically, these are oxidation reactions, they occur in mitochondria, the simplest example is breath. When breathing, complex organic substances are broken down into simple ones, carbon dioxide and energy are released. In general, these two processes are interrelated and go one into the other. In total, the equation of metabolism - metabolism in a cell - can be written as follows:
catabolism + anabolism = cell metabolism = metabolism.
The process of creation is constantly going on in the cell. From simple substances more complex ones are formed, from low molecular weight - high molecular weight. Proteins are synthesized complex carbohydrates, fats, nucleic acids. Synthesized substances are used to build different parts cells, its organelles, secrets, enzymes, reserve substances. Synthetic reactions are especially intense in a growing cell, constantly there is a synthesis of substances to replace the molecules used up or destroyed during damage. In place of each destroyed molecule of a protein or some other substance, a new molecule rises. In this way, the cell retains its shape and chemical composition, despite their continuous change in the process of life.
The synthesis of substances that takes place in a cell is called biological synthesis or biosynthesis for short. All biosynthetic reactions involve the absorption of energy. The set of biosynthetic reactions is called plastic exchange or assimilation(lat. "similis" - similar). The meaning of this process is that those entering the cell from external environment food substances, which differ sharply from the substance of the cell, become the substances of the cell as a result of chemical transformations.
splitting reactions. Complex Substances break down into simpler, high molecular weight - into low molecular weight. Proteins are broken down into amino acids, starch into glucose. These substances are split into even lower molecular weight compounds, and in the end, very simple, energy-poor substances are formed - CO 2 and H 2 O. Splitting reactions in most cases are accompanied by the release of energy.
The biological significance of these reactions is to provide the cell with energy. Any form of activity - movement, secretion, biosynthesis, etc. - needs the expenditure of energy. The set of cleavage reactions is called cell energy exchange or dissimilation. Dissimilation is directly opposite to assimilation: as a result of splitting, substances lose their similarity with the substances of the cell.
Plastic and energy exchanges (assimilation and dissimilation) are in inseparable connection. On the one hand, biosynthesis reactions require the expenditure of energy, which is drawn from cleavage reactions. On the other hand, for the implementation of energy metabolism reactions, constant biosynthesis of enzymes serving these reactions is necessary, since in the process of work they wear out and are destroyed. The complex systems of reactions that make up the process of plastic and energy exchanges are closely connected not only with each other, but also with the external environment.
From the external environment, food substances enter the cell, which serve as a material for plastic exchange reactions, and in the splitting reactions, the energy necessary for the functioning of the cell is released from them. Substances that can no longer be used by the cell are released into the external environment. The totality of all enzymatic reactions of the cell, that is, the totality of plastic and energy exchanges (assimilation and dissimilation) associated with each other and with the external environment, is called metabolism and energy. This process is the main condition for maintaining the life of the cell, the source of its growth, development and functioning.
energy exchange. Energy is needed for the life of an organism. Plants accumulate solar energy in organic matter during photosynthesis. In the process of energy metabolism, organic substances are broken down and the energy of chemical bonds is released. Partly it is dissipated in the form of heat, and partly stored in ATP molecules. In animals, energy metabolism occurs in three stages.
The first stage is preparatory. Food enters the body of animals and humans in the form of complex macromolecular compounds. Before entering cells and tissues, these substances must be broken down to low molecular weight substances that are more accessible for cellular assimilation. At the first stage, hydrolytic splitting of organic substances takes place, which takes place with the participation of water. It proceeds under the action of enzymes in digestive tract multicellular animals, in the digestive vacuoles of unicellular animals, and at the cellular level - in lysosomes. Reactions of the preparatory stage:
proteins + H 2 0 -> amino acids + Q;
fats + H 2 0 -> glycerol + higher fatty acid + Q;
polysaccharides -> glucose +Q.
In mammals and humans, proteins are broken down into amino acids in the stomach and in duodenum under the action of enzymes - peptide hydrolases (pepsin, trypsin, chemotrypsin). The breakdown of polysaccharides begins at oral cavity under the action of the enzyme ptyalin, and then continues in the duodenum under the action of amylase. Fats are also broken down there under the action of lipase. All the energy released in this case is dissipated in the form of heat. The resulting low molecular weight substances enter the bloodstream and are delivered to all organs and cells. In cells, they enter the lysosome or directly into the cytoplasm. If cleavage occurs at the cellular level in lysosomes, then the substance immediately enters the cytoplasm. At this stage, substances are prepared for intracellular cleavage.
Second phase- oxygen free oxidation. The second stage is carried out at the cellular level in the absence of oxygen. It takes place in the cytoplasm of the cell. Consider the breakdown of glucose as one of the key metabolic substances in the cell. All other organic substances (fatty acids, glycerol, amino acids) different stages involved in the process of its transformation. The anoxic breakdown of glucose is called glycolysis. Glucose undergoes a series of successive transformations (Fig. 16). First, it is converted into fructose, phosphorylated - activated by two ATP molecules and converted into fructose diphosphate. Further, the six-atom carbohydrate molecule decomposes into two three-carbon compounds - two molecules of glycerophosphate (triose). After a series of reactions, they are oxidized, losing two hydrogen atoms each, and turn into two molecules of pyruvic acid (PVA). As a result of these reactions, four ATP molecules are synthesized. Since initially two ATP molecules were spent on the activation of glucose, then The overall result is 2ATP. Thus, the energy released during the breakdown of glucose is partially stored in two ATP molecules, and partially consumed in the form of heat. The four hydrogen atoms that were removed during the oxidation of glycerophosphate are combined with the hydrogen carrier NAD + (nicotinamide dinucleotide phosphate). This is the same hydrogen carrier as NADP + , but is involved in energy metabolism reactions.
Generalized scheme of glycolysis reactions:
C 6 H 12 0 6 + 2NAD + - > 2C 3 H 4 0 3 + 2OVER 2H
2ADF - > 2ATP
The reduced NAD 2H molecules enter the mitochondria, where they are oxidized, giving off hydrogen. Depending on the type of cells, tissue, or organisms, pyruvic acid in an oxygen-free environment can further turn into lactic acid, ethyl alcohol, butyric acid, or other organic substances. At anaerobic organisms these processes are called fermentation.
Lactic fermentation:
C 6 H 12 0 6 + 2NAD + -> 2C 3 H 4 0 3 + 2NAD 2H<=>2C 3 H 6 0 3 + 2NAD +
Glucose PVC lactic acid
Alcoholic fermentation:
C 6 H 12 0 6 + 2NAD + -> 2C 3 H 4 0 3 + 2NAD 2H<=>2C 2 H 5 OH + 2C0 2 + 2NAD +
Glucose PVC Ethyl Alcohol
The third stage is biological oxidation, or respiration. This stage occurs only in the presence of oxygen and is otherwise called oxygen. It takes place in the mitochondria. Pyruvic acid from the cytoplasm enters the mitochondria, where it loses a carbon dioxide molecule and turns into acetic acid, combining with the activator and carrier coenzyme-A. The resulting acetyl-CoA then enters into a series of cyclic reactions. The products of oxygen-free cleavage - lactic acid, ethyl alcohol - also further undergo changes and undergo oxidation with oxygen. AT pyruvic acid lactic acid is converted if it was formed with a lack of oxygen in the tissues of animals. Ethanol oxidized to acetic acid and binds to CoA. Cyclic reactions in which acetic acid is converted are called cycle of di- and tricarboxylic acids, or Krebs cycle, named after the scientist who first described these reactions. As a result of a series of successive reactions, decarboxylation occurs - the elimination of carbon dioxide and oxidation - the removal of hydrogen from the resulting substances. Carbon dioxide, which is formed during the decarboxylation of PVC and in the Krebs cycle, is released from mitochondria, and then from the cell and organism during respiration. Thus, carbon dioxide is formed directly in the process of decarboxylation of organic substances. All the hydrogen that is removed from the intermediates combines with the NAD + carrier, and NAD 2H is formed. During photosynthesis, carbon dioxide combines with intermediate substances and is reduced by hydrogen. Here is the reverse process.
General Equation decarboxylation and oxidation of PVC:
2C 3 H 4 0 3 + 6H 2 0 + 10 NAD + -> 6C0 2 + 10 NAD N.
Let us now trace the path of the OVER 2H molecules. They enter the cristae of mitochondria, where the respiratory chain of enzymes is located. On this chain, hydrogen is split off from the carrier with the simultaneous removal of electrons. Each molecule of reduced NAD 2H donates two hydrogens and two electrons. The energy of the removed electrons is very high. They enter the respiratory chain of enzymes, which consists of proteins - cytochromes. Moving through this system in cascades, the electron loses energy. Due to this energy, in the presence of the enzyme ATP-ase, ATP molecules are synthesized. Simultaneously with these processes, hydrogen ions are pumped through the membrane to its outer side. In the process of oxidation of 12 NAD-2H molecules, which were formed during glycolysis (2 molecules) and as a result of reactions in the Krebs cycle (10 molecules), 36 ATP molecules are synthesized. The synthesis of ATP molecules, coupled with the process of hydrogen oxidation, is called oxidative phosphorylation. The final electron acceptor is an oxygen molecule that enters the mitochondria during respiration. Oxygen atoms on the outside of the membrane accept electrons and become negatively charged. Positive hydrogen ions combine with negatively charged oxygen to form water molecules. Recall that atmospheric oxygen is formed as a result of photosynthesis during the photolysis of water molecules, and hydrogen is used to reduce carbon dioxide. In the process of energy exchange, hydrogen and oxygen recombine and turn into water.
The generalized reaction of the oxygen step of the oxidation is:
2С 3 Н 4 0 3 + 4Н + 60 2 -> 6С0 2 + 6Н 2 0;
36ADP -> 36ATP.
So, the yield of ATP molecules during oxygen oxidation is 18 times greater than with oxygen-free.
The overall equation for glucose oxidation in two steps:
C 6 H 12 0 6 + 60 2 -> 6C0 2 + 6H 2 0 + E->Q(warmly).
38ADP -> 38ATP
Thus, during the breakdown of glucose in two stages, a total of 38 ATP molecules are formed, with the main part - 36 molecules - during oxygen oxidation. Such a gain in energy ensured the predominant development of aerobic organisms in comparison with anaerobic ones.
21. Mitotic cell cycle. Characteristics of periods. Mitosis, his biological significance. Amitosis.
Under cell (life) cycle understand the existence of a cell from the moment of its appearance as a result of division to another division or to the death of the cell.
A closely related concept is the mitotic cycle.
Mitotic cycle- this is the life of the cell from division to the next division.
It is a complex of interrelated and coordinated phenomena during cell division, as well as before and after it. Mitotic cycle- this is a set of processes occurring in a cell from one division to the next and ending with the formation of two cells of the next generation. In addition, in the concept life cycle also includes the period of the cell performing its functions and periods of rest. At this time, the further cell fate is uncertain: the cell may begin to divide (enter mitosis) or begin to prepare to perform specific functions.
Main stages of mitosis.
1.Reduplication (self-doubling) of the genetic information of the mother cell and uniform distribution between daughter cells. This is accompanied by changes in the structure and morphology of chromosomes, in which more than 90% of the information of a eukaryotic cell is concentrated.
2. The mitotic cycle consists of four successive periods: presynthetic (or postmitotic) G1, synthetic S, postsynthetic (or premitotic) G2, and mitosis proper. They constitute the autocatalytic interphase (preparatory period).
Phases cell cycle:
1) presynthetic (G1) (2n2c, where n is the number of chromosomes, c is the number of molecules). Occurs immediately after cell division. DNA synthesis has not yet taken place. The cell actively grows in size, stores the substances necessary for division: proteins (histones, structural proteins, enzymes), RNA, ATP molecules. There is a division of mitochondria and chloroplasts (i.e., structures capable of autoreproduction). The features of the organization of the interphase cell are restored after the previous division;
2) synthetic (S) (2n4c). Genetic material is duplicated by DNA replication. It occurs in a semi-conservative way, when the double helix of the DNA molecule diverges into two strands and a complementary strand is synthesized on each of them.
As a result, two identical DNA double helixes are formed, each of which consists of one new and one old DNA strand. The amount of hereditary material is doubled. In addition, the synthesis of RNA and proteins continues. A small part of mitochondrial DNA also undergoes replication (its main part is replicated in the G2 period);
3) postsynthetic (G2) (2n4c). DNA is no longer synthesized, but there is a correction of the shortcomings made during its synthesis in the S period (repair). They also accumulate energy and nutrients, the synthesis of RNA and proteins (mainly nuclear) continues.
S and G2 are directly related to mitosis, so they are sometimes isolated in a separate period - preprophase.
This is followed by mitosis itself, which consists of four phases. The division process includes several successive phases and is a cycle. Its duration is different and ranges from 10 to 50 hours in most cells. At the same time, in cells of the human body, the duration of mitosis itself is 1-1.5 hours, the G2 period of interphase is 2-3 hours, the S-period of interphase is 6-10 hours .
stages of mitosis.
The process of mitosis is usually divided into four main phases: prophase, metaphase, anaphase and telophase. Since it is continuous, the phase change is carried out smoothly - one imperceptibly passes into another.
in prophase the volume of the nucleus increases, and due to the spiralization of chromatin, chromosomes are formed. By the end of prophase, each chromosome is seen to consist of two chromatids. Gradually, the nucleoli and nuclear membrane dissolve, and the chromosomes are randomly located in the cytoplasm of the cell. The centrioles move towards the poles of the cell. An achromatin spindle is formed, some of the threads of which go from pole to pole, and some are attached to the centromeres of chromosomes. The content of genetic material in the cell remains unchanged (2n4c).
In metaphase chromosomes reach maximum spiralization and are arranged in an orderly manner at the equator of the cell, so their counting and study is carried out during this period. The content of genetic material does not change (2n4c).
in anaphase each chromosome "splits" into two chromatids, which from then on are called daughter chromosomes. The spindle fibers attached to the centromeres contract and pull the chromatids (daughter chromosomes) to opposite poles of the cell. The content of genetic material in the cell at each pole is represented by a diploid set of chromosomes, but each chromosome contains one chromatid (4n4c).
in telophase chromosomes located at the poles despiralize and become poorly visible. Around the chromosomes at each pole, a nuclear membrane forms from the membrane structures of the cytoplasm, and nucleoli form in the nuclei. The spindle of division is destroyed. At the same time, the cytoplasm is dividing. Daughter cells have diploid set chromosomes, each of which consists of one chromatid (2n2c).
Demo version
Work instructions
3 hours (180 minutes) are allotted to complete the examination work in biology. The work consists of 3 parts, including 50 tasks.
Part 1 includes 36 tasks (A1-A36). Each question has 4 possible answers, one of which is correct.
Part 2 contains 8 tasks (B1-B8): 3 - with a choice of 3 correct answers out of 6, 3 - for correspondence, 2 - for establishing the sequence of biological processes, phenomena, objects.
Part 3 contains 6 open-ended tasks (С1–С6).
For completing tasks of various complexity, from one to three points are given. Points received for completed tasks are summed up.
Part 1
Choose 1 correct answer out of 4.
A1. main feature alive:
1) movement;
2) weight gain;
3) metabolism;
4) decay into molecules.
A2. The similarity of eukaryotic cells is evidenced by the presence in them:
1) nuclei;
2) plastid;
3) cellulose shells;
4) vacuoles with cell sap.
A3. The structure and functions of the plasma membrane are determined by its constituent molecules:
1) glycogen and starch;
2) DNA and ATP;
3) proteins and lipids;
4) fiber and glucose.
A4. Meiosis differs from mitosis in that:
1) interphases;
2) spindle division;
3) four phases of fission;
4) two consecutive divisions.
A5. Autotrophic organisms include:
1) mukor;
2) yeast;
3) penicillium;
4) chlorella.
A6. In parthenogenesis, an organism develops from:
1) zygotes;
2) vegetative cell;
3) somatic cell;
4) unfertilized egg.
A7. Paired genes of homologous chromosomes are called:
1) allelic;
2) linked;
3) recessive;
4) dominant.
A8. Dogs have black hair BUT) dominates brown ( a), and short-legged ( AT) – above normal leg length ( b). Select the genotype of a black short-legged dog that is heterozygous for leg length only.
1) AABb;
2) Aabb;
3) AaBb;
4) AABB.
A9. Mutational variability in contrast to modification:
1) is reversible;
2) is inherited;
3) characteristic of all individuals of the species;
4) is a manifestation of the norm of the reaction of the trait.
A10. What features of the vital activity of fungi indicate their similarity with plants?
1) the use of solar energy in photosynthesis;
2) unlimited growth throughout life;
3) synthesis of organic substances from inorganic;
4) the release of oxygen into the atmosphere.
A11. The tuber and bulb are:
1) organs of soil nutrition;
2) modified shoots;
3) generative organs;
4) rudimentary shoots.
A12. To which group do plants consisting of cells undifferentiated into tissues belong?
1) mosses;
2) horsetail;
3) algae;
4) lichens.
A13. In insects with complete metamorphosis:
1) the larva is similar to an adult insect;
2) the larval stage is followed by the pupal stage;
3) the larva turns into an adult insect;
4) the larva and pupa eat the same food.
A14. What vertebrates are called the first true land animals?
1) amphibians;
2) reptiles;
3) birds;
4) mammals.
A15. Toxic substances that have entered the human body with food are neutralized in:
1) kidneys;
2) liver;
3) large intestine;
4) pancreas.
A16. Friction during the movement of bones in the joint is reduced due to:
1) articular bag;
2) negative pressure inside the joint;
3) joint fluid;
4) articular ligaments.
A17. When anemia occurs in humans:
1) lack of calcium in the blood;
2) a decrease in the content of hormones in the blood;
3) decrease in hemoglobin content in the blood;
4) violation of the activity of the pancreas.
A18. What letter in the figure indicates the part of the brain in which the center of respiration is located?
1) A;
2) B;
3) B;
4) G.
A19. Infection of humans by Finns bull tapeworm can happen when using:
1) eating unwashed vegetables;
2) water from a stagnant reservoir;
3) poorly fried meat;
4) poorly washed dishes used by the patient.
A20. What criterion of species refers to the area of distribution of the reindeer?
1) environmental;
2) genetic;
3) morphological;
4) geographical.
A21. The source material for natural selection serves:
1) struggle for existence;
2) mutational variability;
3) change in the habitat of organisms;
4) adaptation of organisms to the environment.
A22. The formation of fitness in organisms occurs as a result of:
1) development of new territories by the species;
2) direct impact of the environment on the body;
3) genetic drift and an increase in the number of homozygotes;
4) natural selection and conservation of individuals with useful traits.
A23. In connection with reaching land, the first plants formed:
1) fabrics;
2) disputes;
3) seeds;
4) sex cells.
A24. The biotic components of an ecosystem include:
1) gas composition of the atmosphere;
2) the composition and structure of the soil;
3) features of climate and weather;
4) producers, consumers, decomposers.
A25. Which object is missing in the power circuit below:
leaf litter ® ...... ® hedgehog ® fox?
1) mole;
2) grasshopper;
3) earthworm;
4) mold fungi.
A26. How to prevent human imbalance in the biosphere?
1) increase the intensity economic activity;
2) increase the biomass productivity of ecosystems;
3) take into account environmental patterns in economic activity;
4) study the biology of rare and endangered species of plants and animals.
A27. Hydrolytic cleavage of macromolecular substances in the cell occurs in:
1) lysosomes;
2) ribosomes;
3) chloroplasts;
4) endoplasmic.
A28. Which transfer RNA anticodon corresponds to the TGA triplet in the DNA molecule?
1) ACU;
2) ZUG;
3) UGA;
4) AHA.
A29. In interphase before mitosis in the cell:
1) chromosomes line up in the plane of the equator;
2) chromosomes diverge to the poles of the cell;
3) the number of DNA molecules is halved;
4) the number of DNA molecules doubles.
A30. At monohybrid cross of a heterozygous individual with a homozygous recessive in their offspring, there is a splitting of signs according to the phenotype in the ratio:
1) 3: 1;
2) 9: 3: 3: 1;
3) 1: 1;
4) 1: 2: 1.
A31. In breeding for obtaining new polyploid plant varieties:
1) individuals of two pure lines are crossed;
2) cross parents with their offspring;
3) multiply increase the set of chromosomes;
4) increase the number of homozygous individuals.
A32. The shape of the body of tadpoles, the presence of a lateral line, gills, a two-chambered heart, and one circle of blood circulation indicate a relationship:
1) cartilaginous and bony fishes;
2) lancelet and fish;
3) amphibians and fish;
4) reptiles and fish.
A33. Man, unlike animals, when he hears a word, perceives:
1) the height of its constituent sounds;
2) direction sound wave;
3) the degree of sound volume;
4) the meaning contained in it.
A34. In the process of absorption through the villi small intestine go directly into the blood
1) glucose and amino acids;
2) glycerol and fatty acids;
3) proteins and fats;
4) glycogen and starch.
A35. Which of the following aromorphic traits allowed mammals to master a variety of habitats?
1) warm-bloodedness;
2) heterotrophic nutrition;
3) pulmonary respiration;
4) development of the cerebral cortex.
A36. What is the reason for changing one biocenosis to another?
1) change weather conditions;
2) seasonal changes in nature;
3) fluctuations in the number of populations of one species;
4) change in the habitat by living organisms.
Part 2
Choose 3 correct answers out of 6 and write down the chosen letters in alphabetical order.
IN 1. A prokaryotic cell is characterized by the presence of:
A) ribosome;
B) mitochondria;
B) a formalized core;
D) plasma membrane;
D) endoplasmic reticulum;
E) one circular DNA.
IN 2. In connection with upright posture in humans:
A) are released upper limbs;
B) the foot takes on an arched shape;
AT) thumb hands opposes the rest;
D) the pelvis expands, its bones grow together;
D) brain department the skull is smaller than the facial one;
E) the hairline is reduced.
IN 3. What are the similarities between natural and artificial ecosystems?
A) a small number of species;
B) the presence of power circuits;
C) a closed circulation of substances;
D) the use of solar energy;
D) use of additional energy sources;
E) the presence of producers, consumers, decomposers.
When completing tasks B4–B6, establish a correspondence between the contents of the first and second columns. Write in the table the letters of the selected answers.
AT 4. Establish a correspondence between the trait of animals and the class for which this trait is characteristic.
1) fertilization is internal;
2) fertilization in most species is external;
3) indirect development;
4) reproduction and development takes place on land;
5) thin skin covered with mucus;
6) eggs with a large supply of nutrients.
A) amphibians;
B) reptiles.
AT 5. Match between blood vessels person and the direction of blood flow in them.
BLOOD VESSELS
1) veins of the pulmonary circulation;
2) veins great circle blood circulation;
3) arteries of the pulmonary circulation;
4) arteries of the systemic circulation.
DIRECTION OF BLOOD MOVEMENT
A) from the heart
B) to the heart.
AT 6. Establish a correspondence between the characteristics of metabolism and organisms for which these features are characteristic.
FEATURES OF METABOLISM
1) the use of sunlight energy for the synthesis of ATP;
2) the use of energy contained in food for the synthesis of ATP;
3) use only ready-made organic substances;
4) synthesis of organic substances from inorganic;
5) the release of oxygen in the process of metabolism.
ORGANISMS
A) autotrophs;
B) heterotrophs.
When performing tasks B7–B8, set the correct sequence biological processes, phenomena, practical actions. Write down the letters of the selected answers in the table.
AT 7. Set the sequence reflecting the systematic position of the species Cabbage white in the classification of animals, starting with the smallest category.
A) the class Insects;
B) species Cabbage white;
C) detachment Lepidoptera;
D) phylum Arthropoda;
E) genus Garden whites;
E) the Belyanka family.
Part 3
For task C1, give a short free answer, and for tasks C2-C6 - a full detailed answer.
C1. In the seventeenth century Dutch scientist van Helmont conducted an experiment. He planted a small willow in a tub of soil, after weighing the plant and soil, and only watered it for several years. After 5 years, the scientist weighed the plant again. Its weight increased by 63.7 kg, the weight of the soil decreased by only 0.06 kg. Explain what caused the increase in the mass of the plant, what substances from the external environment ensured this increase.
C2. Find the errors in the given text, correct them, indicate the numbers of the sentences in which they are made, write down these sentences without errors.
1. In plants, like in all organisms, there is a metabolism.
2. They breathe, eat, grow and reproduce.
3. When breathing, they absorb carbon dioxide and release oxygen.
4. They grow only in the first years of life.
5. All plants are autotrophic organisms by type of nutrition; they reproduce and spread using seeds.
C3. What underlies the combinative variability of organisms? Explain the answer.
C4. Why red blood cells are destroyed if they are placed in distilled water? Justify the answer.
C5. In one DNA molecule, nucleodides with thymine (T) make up 24% of total number nucleotides. Determine the number (in%) of nucleotides with guanine (G), adenine (A), cytosine (C) in the DNA molecule and explain the results.
C6. According to the pedigree shown in the figure, establish the nature of the inheritance of the trait highlighted in black (dominant or recessive, sex-linked or not), the genotypes of children in the first and second generation.
Answers
Part 1
For the correct performance of tasks A1–A36, 1 point is given.
A1 – 3; A2 – 1; A3 – 3; A4 – 4; A5 – 4; A6 – 4; A7 – 1; A8 – 1; A9 – 2; A10 – 2; A11 – 2; A12 – 3; A13 – 2; A14 – 2; A15 – 2; A16 – 3; A17 – 3; A18 – 1; A19 – 3; A20 – 4; A21 – 2; A22 – 4; A23 – 1; A24 – 4; A25 – 3; A26 – 3; A27 – 1; A28 – 3; A29 – 4; A30 –3; A31 – 3; A32 – 3; A33 – 4; A34 – 1; A35 – 1; A36 – 4.
Part 2
For the correct performance of tasks B1–B6, 2 points are given. If the answer contains one mistake, then the examiner receives 1 point. For an incorrect answer or an answer containing 2 or more errors, 0 points are given.
For the correct answer to tasks B7–B8, 2 points are also given. 1 point is given if the answer incorrectly determines the sequence of the last two elements or they are missing when correct definition all previous elements. In other cases, 0 points are given.
IN 1– AGE; IN 2- ABG; IN 3– BGE; AT 4- BAABAB; AT 5- BBAA; AT 6- ABBAA; AT 7- BDEVAG; AT 8- GAVBD.
Part 3
Other formulations of the answer are allowed that do not distort its meaning.
C1. Response elements: 1) the mass of the plant increased due to organic substances formed during photosynthesis; 2) in the process of photosynthesis, water and carbon dioxide come from the external environment.
The answer includes all the above elements of the answer, does not contain biological errors 2 points.
The answer includes only 1 of the above response elements and does not contain biological errors OR the answer includes 2 of the above elements, but contains non-gross biological errors - 1 point.
Wrong answer - 0 points
C2. Response elements: 3 - when breathing, plants absorb oxygen and release carbon dioxide; 4 - plants grow throughout their lives; 5 - not all plants form seeds.
All three errors are indicated and corrected in the answer - 3 points.
2 errors are indicated and corrected in the answer OR 3 errors are indicated, but only 2 of them are corrected - 2 points.
1 error is indicated and corrected in the answer OR 2-3 errors are indicated, but 1 of them is corrected - 1 point.
Errors are not indicated OR 1-3 errors are indicated, but none of them is corrected - 0 points.
When evaluating tasks C3–C5, take into account the following items response.
The answer is correct and complete, includes all the above elements of the answer, does not contain biological errors - 3 points.
The answer is correct, but incomplete, includes 2 of the above response elements and does not contain biological errors OR the answer includes 3 of the above elements, but contains non-gross biological errors - 2 points.
The answer is incomplete, includes 1 of the above response elements and does not contain biological errors OR the answer includes 1-2 of the above elements, but contains non-gross biological errors - 1 point.
Wrong answer - 0 points.
C3. response elements. Combinative variability is based on the following processes: 1) crossing over leads to a change in the combination of genes in homologous chromosomes; 2) meiosis, as a result of which an independent divergence of chromosomes into gametes occurs; 3) a random combination of gametes during fertilization.
C4. Answer elements: 1) the concentration of substances in erythrocytes is higher than in water; 2) due to the difference in concentration, water enters the erythrocytes; 3) the volume of red blood cells increases, as a result of which they are destroyed.
C5. Response elements: 1) adenine (A) is complementary to thymine (T), and guanine (G) is complementary to cytosine (C), so the number of complementary nucleotides is the same; 2) the number of nucleotides with adenine is 24%; 3) the amount of guanine (G) and cytosine (C) together make up 52%, and each of them - 26%.
C6. Answer elements: 1) dominant trait, not sex-linked; 2) genotypes of children of the 1st generation: daughter Ah, daughter aa, son Ah; 3) genotypes of children of the 2nd generation: daughter Ah(other genetic symbolism is allowed, which does not distort the meaning of the solution of the problem).
Control testing No. 2. Cell structure.
TIME - 35 MINUTES!
Part A
Part A includes tasks with 4 possible answers, one of which is correct.
A1. All functions of the whole organism are performed by the cell.
1) ciliates-shoes
3) human liver
4) birch leaf
A2. What structure controls the life processes in the cells of plants, animals, fungi
1) cytoplasm
2) mitochondrion
3) chloroplast
A3. In the Golgi complex, unlike chloroplasts,
1) transport of substances
2) oxidation of organic substances to inorganic
3) accumulation of substances synthesized in the cell
4) synthesis of protein molecules
A4. The similarity of the functions of lysosomes and mitochondria lies in what happens in them
1) enzyme synthesis
2) synthesis of organic substances
3) reduction of carbon dioxide to carbohydrates
4) breakdown of organic substances
A5. Hydrolytic cleavage of macromolecular substances in the cell is carried out in
1) lysosomes
2) cytoplasm
3) endoplasmic reticulum
4) mitochondria
A6. All the features below, except for two, can be used to describe the structure and functions of mitochondria. Identify two features that “fall out” of the general list, and write down in response the numbers under which they are indicated.
1) break down biopolymers to monomers 2) contain interconnected grana
3) have enzymatic complexes located on cristae
4) oxidize organic substances with the formation of ATP
5) have outer and inner membranes
A7. All of the features below, except for two, can be used to describe the functions of the cytoplasm. Identify two features that “fall out” of the general list, and write down in response the numbers under which they are indicated.
1) internal environment, in which organelles are located 2) glucose synthesis
3) the relationship of metabolic processes 4) the oxidation of organic substances to inorganic
5) communication between cell organelles
A8. All of the following characteristics, except for two, can be used to describe common properties characteristic of mitochondria and plastids. Identify two features that "drop out" of general list, and write down in response the numbers under which they are indicated.
1) do not divide during the life of the cell 2) have their own genetic material
3) contain enzymes of oxidative phosphorylation 4) have a double membrane
5) participate in the synthesis of ATP
A9. All of the features listed below, except for two, can be used to describe the cell organoid shown in the figure. Identify two signs that “fall out” from the general list, and write down the numbers under which they are indicated in the table in the table.
1) found in plant and animal cells 2) characteristic of prokaryotic cells
3) participates in the formation of lysosomes 4) forms secretory vesicles
5) two-membrane organoid
A10. Consider the proposed scheme. Write in the answer the missing term, indicated in the diagram with a question mark.
A11. Consider the proposed scheme of RNA types. Write in the answer the missing term, indicated in the diagram with a question mark.
A12. All the substances presented in the diagram, except for two, have in their composition a nitrogenous base - adenine. Identify two substances that "drop out" of the general list, and write it down.
| 1) | 2)  |
3)  | 4)  |
5)
 |
A13. From the proposed list of chemical elements, select organogens. Choose two correct answers from five and write down the numbers under which they are indicated.
1) oxygen 2) nitrogen 3) magnesium 4) chlorine 5) iodine
A14. Choose two correct answers from five and write down the numbers under which they are indicated. The cellular level of organization is the same as the organism level.
1) bacteriophages 2) dysenteric amoeba 3) poliomyelitis virus
4) wild rabbit 5) green euglena
A15. Choose two correct answers from five and write down the numbers under which they are indicated. In a light microscope, you can see
1) cell division 2) DNA replication 3) transcription
4) water photolysis 5) chloroplasts
A16. Choose two correct answers from five and write down the numbers under which they are indicated. paleontologists study
1) patterns of development of organisms 2) distribution of living beings on Earth
3) habitat of organisms 4) fossil remains of animal organisms
5) study of the fossilized remains of pollen and spores of ancient plants
A17. Choose two correct answers from five and write down the numbers under which they are indicated. To private biological methods research method
1) experimental 2) observation 3) genealogical
4) modeling 5) hybridological
A18. Choose two correct answers out of five and write down the numbers under which they are indicated in the table. In which of the scientific research was the experimental method used?
1) study of the flora of the tundra 2) refutation of the theory of spontaneous generation by L. Pasteur 3) creation cell theory 4) creation of a DNA molecule model 5) study of photosynthesis processes
A19. Choose two correct answers from five and write down the numbers under which they are indicated. The banding method is used for
1) determining the timing and routes of bird migration 2) studying the mechanisms of bird flight at different heights 3) determining the behavioral characteristics of poultry
4) assessing the damage caused to humans by birds 5) determining the life expectancy of birds
Part B
In the tasks, choose three correct answers out of six.
Match the contents of the first and second columns.
For the correct performance of the tasks of parts B1-B8, 2 points are given. If the answer contains one mistake, then the examiner receives one point. For an incorrect answer or an answer containing 2 or more errors, 0 points are given.
IN 1. Choose three functions that are unique to proteins.
1) energy 2) catalytic 3) propulsion 4) transport
5) structural 6) storage
IN 2. What are the features of the structure and functions of ribosomes? Write down the numbers in ascending order.
1) have one membrane 2) consist of DNA molecules 3) break down organic substances
4) consist of large and small particles 5) participate in the process of protein biosynthesis
6) consist of RNA and protein
IN 3. Choose structures that are characteristic only for a plant cell.
1) mitochondria 2) chloroplasts 3) cell wall 4) ribosomes
5) vacuoles with cell sap 6) Golgi apparatus
AT 4. The cytoplasm performs functions in the cell
1) the internal environment in which the organelles are located 2) glucose synthesis
3) the relationship of metabolic processes
4) oxidation of organic substances to inorganic
5) communication between cell organelles 6) synthesis of ATP molecules
AT 5. Which of the following functions is performed by the plasma membrane of a cell? Write down the numbers in ascending order.
1) participates in the synthesis of lipids 2) carries out active transport of substances
3) participates in the process of phagocytosis 4) participates in the process of pinocytosis
5) is a site for the synthesis of membrane proteins 6) coordinates the process of cell division
AT 6 Choose the features of the structure and functions of chloroplasts
1) inner membranes form cristae 2) many reactions take place in grains
3) glucose synthesis occurs in them 4) they are the site of lipid synthesis
5) consist of two different particles 6) two-membrane organelles
AT 7. Which of the following organelles are membranous
1) lysosomes 2) centrioles 3) ribosomes 4) microtubules 5) vacuoles 6) leukoplasts
AT 8. Establish a correspondence between cell organelles and their functions
Part C
C1. In a DNA molecule, the number of nucleotides with cytosine is 15% of the total. What is the percentage of nucleotides with adenine in this molecule?
C2. What is called plasmolysis? How does water move through cell membrane? What are the causes of plasmolysis? What is called deplasmolysis?
C3. What is osmosis? What substances are involved in the formation osmotic pressure?
C4. What types of RNA do you know? What functions do they perform and where are they located?