Tasks from 1.

1. What must be included in the instructions for applying a tourniquet to stop venous bleeding?

1) The tourniquet is applied below the injury site on a soft tissue.

2) The tourniquet is applied for no more than 1-1.5 hours, the time of its application is indicated in a note placed under the tourniquet.

2. Why do people who eat a lot of carbohydrates gain weight?

1) Excess carbohydrates in the human body are converted into fats.

2) Excess fat in the human body is stored in the reserve, which leads to weight gain.

1) Vitamin D is formed in the skin under the influence of ultraviolet rays.

2) Vitamin D prevents rickets.

4. For what purpose is a person's pulse measured?

1) To determine the number of heartbeats per minute.

2) To determine the force of contractions of the heart.

5. Why should food be chewed thoroughly?

1) Well-chewed food is quickly saturated with digestive juices.

2) It speeds up the process of converting complex insoluble organic substances into less complex ones that can be absorbed into the blood and lymph.

6. By what signs do you distinguish a modified shoot from a modified root?

1) The modified root has no buds

2) Modified roots do not have scales - modified leaves.

7. The researcher took two groups of cells and placed them in different culture tubes. In one group of cells, he removed the nucleus. Another group of cells remained unharmed. How will the number of cells in different groups change over time and why?

1) The nucleus is responsible for cell division.

2) Without a nucleus, cells do not divide and die after a while.

8. All dog cells contain 78 chromosomes. Only in germ cells there are two times fewer chromosomes. How can this fact be explained, knowing about the sexual reproduction of animals?

1) the number of chromosomes decreases during the formation of gametes.

2) during fertilization, the chromosome set is restored.

3) this is how the genetic constancy of the species is maintained.

9. How can one explain that multicellular plants consist of several types of tissues?

1) the need to absorb and deliver nutrients to different distances in connection with landfall.

2) in connection with the performance of various functions by plant organs.

10. What is the difference between artificial and acquired natural immunity?

1) artificial immunity is acquired after vaccination or administration of therapeutic serum.

2) Antibodies are produced after the introduction of the vaccine or are administered ready-made.

3) Natural immunity is inherited. Antibodies are produced throughout the life of the body.

11. What features of development helped plants conquer land?

1) The emergence of organs that perform certain functions.

2) the emergence of specialized tissues.

3) The emergence of the flower and the seed.

4) Reducing the dependence of the reproduction of the organism on water.

12. How can one explain the differences between animals of the same species, one breed?

1) The difference in the nucleotide sequence in the genes encoding similar proteins. (Genes encoding proteins of the same function may differ slightly in individuals of the same species)

2) The difference in the sequence of amino acids in protein molecules.

13. What features of a camel allow it to exist in the desert?

1) Wide flat hooves that create support in the sands.

2) The ability to go without food for a long time or to feed on the meager vegetation of deserts.

3) Reserves of fat in the humps, capable of being oxidized to water.

14. How do bacteria affect the state of the host organism?

1) Bacteria penetrate the cells of the host organism, poisoning it with their waste products.

2) Reproducing in the host organism, bacteria block the normal vital activity of its cells.

3) They use the substances and energy of the host organism for their life activity.

15. In the leaves of plants, the process of photosynthesis proceeds intensively. Does it occur in mature and unripe fruits?

1) photosynthesis occurs in immature fruits (while they are green), since they contain chloroplasts;

2) as they mature, chloroplasts turn into chromoplasts, in which photosynthesis does not occur.

16. It is known that in sphagnum bogs, despite the large amount of moisture, water is inaccessible to many plants. What is it connected with?

1) the roots, like other organs of the plant, carry out the process of respiration and need oxygen; in sphagnum bogs, due to poor aeration, it is not enough;

2) the growth of roots is also hindered by acidification of the water and soil of the swamps;

3) and in the water and soil of sphagnum bogs, toxic substances accumulate that interfere with the development of plants.

17. Why do many seeds fail to germinate when there is too much water in the soil?

With an excess of water in the soil, there is a lack of oxygen, which is necessary for the respiration of the plant. The germinating seeds of most plants obtain a significant portion of their oxygen from the free spaces of the soil, and not from the water.

18. It is known that before transplanting young plants into the ground, they are picked (they pinch off the tip of the main root). Why do they do it?

1) when picking plants, the growth of adventitious and lateral roots is activated;

2) due to the increase in the total number of adventitious and lateral roots, the mineral nutrition of the plant improves, which stimulates its growth.

19. With the introduction of potatoes into the culture in Russia, potato riots arose. Why did the peasants not want to grow this plant?

1) the peasants did not know that tubers should be eaten, and they ate green berries;

2) Potato berries are poisonous and cause severe poisoning.

20. When picking cabbage seedlings, gardeners pinch the top of the main root, and when propagating currant bushes, they use stem cuttings on which adventitious roots develop. Both of these flowering plants belong to the dicotyledonous class. Explain what type of root system will be in the cabbage grown from this seedling, and what type will be in the currant grown from the stem cutting.

1) The type of root system is initially taproot in cabbage and currant (dicotyledonous plants).

2) When picking cabbage, after pinching, the main root stops growing in length (since the division and growth zones are removed) and lateral and adventitious roots develop. When rooting stem cuttings of currant, adventitious roots develop. Thus, the root system in both cases will become similar to fibrous (primary development of lateral and adventitious roots).

21. The flowers of many angiosperms are pollinated by insects. Explain the mutual benefits of cross-pollination for insects and plants.

Response elements:

1) For plants: thanks to insects, the likelihood of pollination increases, the possibility of acquiring new traits by offspring (variability and better fitness) increases.

2) For insects: plants are a source of food (pollen and nectar), a shelter.

22. What is the purpose of whitewashing trunks and large branches of fruit trees?

To protect against sunburn and pests.

23. Why does plowing the soil improve the living conditions of cultivated plants?

Response elements:

1) promotes the destruction of weeds and reduces competition with cultivated plants;

2) contributes to the supply of plants with water and minerals;

3) increases the supply of oxygen to the roots.

24. In the 17th century, the 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.

1) the mass of the plant increased due to organic substances formed during photosynthesis;

2) in the process of photosynthesis, water and carbon dioxide are used, which come from the external environment.

25. What is the significance of leaf fall for mid-latitude plants?

1) Leaf fall is an adaptation of plants to reduce water evaporation in autumn and winter.

2) It also reduces the likelihood of branches breaking off under the weight of snow.

3) In addition, this is how harmful substances accumulated over the summer are removed from the plant.

26. Why are lichens so hardy?

The endurance of lichens is explained by the possibility of both autotrophic and heterotrophic nutrition, as well as the ability to fall into a state of suspended animation, in which the body is severely dehydrated.

27. What harm does a tinder fungus bring to a birch?

28. Name the adaptations of plants to life in dry conditions.

Response elements:

1) the root system of plants penetrates deep into the soil, reaches the groundwater or is located in the surface layer of the soil;

2) in some plants, water is stored in leaves, stems and other organs during drought;

3) the leaves are covered with a wax coating, pubescent or modified into spines or needles.

29. What is the significance in plant life of beekeepers placing beehives on buckwheat fields?

Bees feed on pollen and nectar of buckwheat, carry out cross-pollination, which increases the yield of plants.

30. Why does potato yield increase after hilling?

Hilling stimulates the formation of adventitious roots, which means it increases the mass of the root system. As a result, root nutrition improves and potato yield increases.

31. Why can lichens live in barren places where other organisms cannot survive?

Lichen is a symbiotic organism. Its body (thallus) consists of fungus and algae. Lichens can grow on rocks, on walls, on sand. They don't need soil. The hyphae of the fungus absorb the moisture of rain, dew and fog with their entire surface. Unicellular algae containing chlorophyll produce organic matter during photosynthesis.

32. Why pinch the main root of some cultivated plants?

To stimulate the growth of adventitious and lateral roots developing in the upper, more fertile soil layer.

33. What are the consequences of applying too much mineral fertilizer to the soil?

to environmental pollution.

34. Why is it necessary to loosen the soil when growing plants?

Loose soil contains more oxygen needed for plant respiration. In addition, soil capillaries are broken during loosening, through which water easily rises to the surface and then evaporates. Thus, moisture is retained in the soil (which is why loosening is often called dry irrigation).

35. Experienced gardeners apply fertilizers to the soil along the edges of the near-stem circles of fruit trees, and do not distribute them evenly. Explain why?

The root system grows, the suction zone moves behind the root tip. Roots with a developed suction zone - root hairs - are located along the edges of the near-trunk circles.

36. What is the basic rule to follow when collecting mushrooms to preserve their numbers?

It is impossible to damage the mycelium, since new fruiting bodies will not grow on the destroyed mycelium.

1) Treatment of seeds before sowing with pesticides.

2) The use of crop rotation.

3) Sowing plant varieties resistant to smut fungi.

38. Ornithologists drew attention to the fact that, as a rule, in the nests of different birds, all eggs with a blunt end face the outer wall of the nest or upwards. Explain this phenomenon.

1) there is an air chamber at the blunt end of the egg;

2) the position of the egg contributes to better gas exchange with the external environment, which is necessary for the respiration of the embryo.

39. The Red Book of Russia includes 65 species of mammals and 122 species of birds. Explain what anthropogenic factors have led to a sharp reduction in their numbers at the present time.

1) Pollution of all living environments, climate change.

2) Plowing the soil, melioration.

3) Mining.

4) Intensive construction (development of new territories), increased noise levels.

5) Hunting, etc.

40. How is the adaptation of birds to seasonal changes in the nature of central Russia manifested?

1) molting, the development of a dense feather cover;

2) storage of fat;

3) storage and change of feed;

4) travel and flights.

41. Explain what the toothless and barley eat and why they are called "bottom filters".

1) toothless and barley feed on organic particles that enter the mantle cavity with the flow of water and are filtered out by cilia,

2) passing through a large amount of water, they purify it from organic suspensions and microorganisms.

1) purification of drinking water;

2) sanitary control at slaughterhouses;

3) proper cooking;

4) compliance with the rules of personal hygiene.

43. Why, with the onset of a hot and dry period in the desert, do turtles hibernate and endure adverse conditions in this state?

1) at this time, animals lack moisture and food;

2) at rest, the metabolism slows down, hence the need for food and water is sharply reduced.

44. In the spring in central Russia, insectivorous birds arrive much later than herbivorous ones. How can this be explained?

Insectivorous birds cannot provide themselves and their offspring with food early in spring due to the absence of insects at this time.

45. At what stages of development does the Colorado potato beetle harm plants?

Having a gnawing mouth apparatus, both the larva and the adult insect of the Colorado potato beetle consume the aerial parts (mainly leaves) of the same plants (usually nightshade), which cause them great harm.

46. Why do most fish and mammals living in the aquatic environment have a streamlined body shape?

1) Water is denser than air.

2) When moving, friction occurs.

3) Streamlined shape reduces resistance to water flow.

47. What biological explanation can be given to the fact that a person carrying very hot tea in an expensive cup suffers pain?

The reason is the conditional inhibition of the pain reflex.

48. Why is communication and exercise most important for a 1 to 3 year old child?

It is at this time that the psychophysical development of the child takes place, speech, thinking, the cerebral cortex, the consistency and accuracy of movements, muscles, and the curves of the spine are formed. In addition, it is during this period that the child begins to realize himself as a person and his social consciousness begins to form. If during this period the child is deprived of human society and physical activity, there will be a lag in psychophysical development. Example: Mowgli children.

49. How will the blood composition change in a climber who spends a week at high altitude? Why?

The number of red blood cells that supply oxygen to the cells will increase, because there is little oxygen at a height.

50. Why does a person unmistakably find the switch in his own house, and look for it in someone else's for some time, even if he has already been there more than once?

In a familiar environment, the conditioned reflex constantly supports, and in an unusual environment it fades away.

51. What is puberty in humans?

Puberty is the period that occurs in boys and girls during adolescence. It is accompanied by complex adjustments in the body and preparation for reproductive function.

The height of a person, his mass increases, secondary sexual characteristics are formed. In boys, spermatozoa mature. Girls start menstruating. Increases the level of sex hormones in the blood.

52. Why is the color of objects not perceived in peripheral vision?

Response elements:

1) Cones are responsible for color perception, which are located in the center of the retina.

2) With lateral vision, the image of an object is formed on the periphery of the retina, where there are no cones, and there are only daddies.

53. What is digestion?

The process of mechanical and chemical processing of food and its transformation into simpler and more soluble compounds that can be absorbed, carried by the blood and lymph and assimilated by the body as a plastic and energy material.

54. How many teeth and what kind of teeth does an adult have?

An adult has 32 teeth: in each half of the upper and lower jaws, there are 2 incisors, 1 canine, 2 small molars and 3 large molars.

55. What measures should be taken to combat pathogenic microorganisms?

1) compliance with the rules of personal hygiene;

2) vaccination of the population;

3) disinfection of objects;

4) sterilization or pasteurization of water and food.

56. Why are some amino acids called essential?

Essential amino acids are not synthesized in animals and humans, they must come from plant foods and cannot be replaced by other nutrients.

57. What is the difference between vaccination and the introduction of therapeutic serum?

Response elements:

I) when vaccinated, a vaccine is introduced into the body (killed or weakened pathogens or their poisons);

2) when vaccinated, the body itself produces protective antibodies; 3) therapeutic serum contains ready-made antibodies.

58. Why do athletes have a higher lung capacity than untrained people?

Vital capacity is the maximum amount of air a person can exhale after taking the deepest breath possible. The mechanism of inhalation and deep exhalation is carried out with the participation of skeletal muscles and the diaphragm. The more developed the skeletal muscles, the more they can increase the volume of the chest, and hence the lungs on inspiration, and the more they can compress the chest during a deep exhalation.

59. Why is carbon monoxide poisoning dangerous for humans?

The iron contained in hemoglobin is capable of forming an unstable compound with oxygen molecules, oxyhemoglobin, when an erythrocyte passes through the capillaries of the lungs. When passing through tissues, oxyhemoglobin releases oxygen, while it is again converted into hemoglobin, which attaches carbon dioxide to itself. The combination of hemoglobin with carbon dioxide (carbohemoglobin) is unstable and is released from carbon dioxide in the lungs. In case of carbon monoxide poisoning, a very strong connection of hemoglobin with this gas is formed - carboxyhemoglobin, it blocks hemoglobin and turns off red blood cells from gas exchange. This is why carbon monoxide poisoning is deadly.

60. Why is damage to the medulla oblongata dangerous to life?

1) In the medulla oblongata are concentrated centers that regulate the vital functions of the body (respiration, cardiovascular activity, etc.)

2) Termination of the activities of these centers leads to the death of a person

61. Why can't you drive a car while intoxicated?

1) Alcohol primarily affects the cerebellum.

2) Damage to the cerebellum leads to a loss of the ability to make precise and coordinated movements.

62. What causes bad posture?

1) Incorrect body position when standing and sitting

2) Insufficient development of the back muscles

63. How important is the length of the small intestine for digestion?

1) The large length of the small intestine allows you to complete the conversion of food organic substances into soluble compounds

2) The large length of the small intestine facilitates the absorption of nutrients

64. What features of the inner surface of the small intestine provide intensive absorption of nutrients in it?

1) Intensive absorption of nutrients is provided by a large area of ​​the suction surface, which is many times greater than the surface of the human body. 2) The area of ​​the suction surface increases due to the presence on the inner side of the small intestine of a large number of villi and microvilli covered with epithelial tissue.

65. Why should food of animal origin be included in the human diet?

1) Plant proteins, unlike animal proteins, do not contain all the amino acids necessary for the formation of proteins specific to the human body

2) Animal fats are closer in composition to human fats than vegetable fats.

66. How is the excretory function of the skin carried out in humans?

I) There are sweat glands in the skin

2) Sweat glands produce sweat, which contains urea, uric acid, ammonia and other metabolic products.

67. Why does a person go blind if his optic nerve function is impaired?

1) Distinguishing visual stimuli occurs in the occipital zone of the cerebral cortex

2) If the functions of the optic nerve are impaired, nerve impulses cannot reach the visual centers of the occipital zone of the cerebral cortex

68. Can a person eat only fats, excluding protein foods from the diet?

1) Can't.

2) The absence of proteins will lead to the fact that the following functions will not be performed in the cells: enzymatic, motor, protective, transport.

3) The synthesis of proteins from fats is impossible, because proteins have a more complex structure (their molecules include nitrogen and sulfur).

69. What happens to epithelial tissue cells if they are placed in water? Justify the answer.

1) the concentration of substances in the cell is higher than in the surrounding water;

2) water enters the cell, the volume of which increases;

3) under the pressure of water, the plasma membrane ruptures, the cell dies.

70. What is the harmful effect of drugs on human offspring?

Drugs are mutagenic, meaning they can cause changes in genes and chromosomes. Most often, these mutations are harmful to humans.

71. What substances are excreted from the human body by various organs that perform an excretory function?

The excretory function in the human body is performed by: kidneys, skin, lungs.

1) carbon dioxide and water vapor are removed from the human body through the lungs;

2) water, a small amount of urea, salts are removed through the sweat glands of the skin;

3) through the kidneys, the end products of nitrogen metabolism, salts, and water are removed.

72. What role does the breakdown of organic matter play in the life of a cell?

1) When organic matter is broken down, energy is released

2) Energy is used for the life of the cell

73. What role does oxygen play in human life?

1) Oxygen causes the oxidation of organic substances in cells and tissues

2) When oxidized, energy is released

74. Why can the number of commercial fish be sharply reduced when predatory fish are destroyed in the reservoir?

1) the destruction of predators leads to a sharp increase in the number of herbivorous fish and increased competition between them;

2) a large number of herbivorous fish contributes to a decrease in the food supply, the spread of various diseases among them, this will lead to mass death of fish.

75. What changes in the ecosystem of the meadow can be caused by a decrease in the number of pollinating insects?

1) reduction in the number of insect pollinated plants, changes in the species composition of plants;

2) reduction in the number and change in the species composition of herbivorous animals; 3) reduction in the number of insectivorous animals.

76. Based on the rule of the ecological pyramid, determine how much grain is needed for the forest to grow one eagle owl weighing 3.5 kg if the food chain looks like:

grain of cereals - mouse vole - polecat - eagle owl.

1) according to the rule of the ecological pyramid, the biomass of each subsequent trophic level decreases

about 10 times;

2) therefore, to feed the eagle owl, 35 kg of ferret biomass is needed (if the mass of one ferret is about 0.5 kg, then this is 70 ferrets; 000 voles), which need 3,500 kg of grain to feed.

77. Why is acid rain dangerous?

First of all, heavy metal oxides that enter the soil with rain are toxic. Underground waters penetrate into reservoirs and poison them. In turn, this threatens the death of the population of reservoirs. Poisonous substances also affect the composition of the soil, the root systems of plants, and this leads to the inhibition of their vital activity and death.

78. Ants live in the stems of some plants. What is the use of the plant from the ants, and the ants from the plant?

79. Fishermen know that there are more fish in the rivers and streams developed by beavers than in reservoirs where there are no beavers. Explain this fact?

1) beavers build dams that prevent the drift of small aquatic animals that serve as food for fish;

2) stagnant and shallow water in ponds dammed with beavers warms up well, which contributes to the creation of conditions for the spawning of river fish and the favorable development of fry.

80. In the spruce forest, herbaceous plants are much less than in the birch grove. Explain this phenomenon.

1) in a grove, much more light passes through the crowns of trees than in a spruce forest, light is a limiting factor for many plants;

2) only shade-tolerant herbaceous plants can exist in a spruce forest.

81. Humans use chemicals to control pests. Indicate at least 3 changes in the life of an oak forest if all herbivorous insects in it are chemically destroyed. Explain why these changes will occur.

1) the number of insect pollinated plants will decrease sharply, since herbivorous insects are pollinators of plants;

2) the number of insectivorous organisms (consumers of the second order) will sharply decrease or disappear due to disruption of food chains;

3) part of the chemicals used to kill insects will enter the soil, which will lead to disruption of plant life, death of soil flora and fauna, all violations can lead to the death of oak forests.

82. In some forest biocenoses, mass shooting of diurnal birds of prey was carried out to protect chicken birds. Explain how this event affected the number of chickens.

Answer elements: 1) at first, the number of chickens increased, since their enemies (naturally regulating the number) were destroyed; 2) then the number of chickens decreased due to lack of food; 3) the number of sick and weakened individuals increased due to the spread of diseases and the absence of predators, as a result of which their numbers decreased.

83. What is the ecological significance of nodule bacteria for plants?

Nodule bacteria form a symbiosis with leguminous plants and are involved in the fixation of atmospheric nitrogen into mineral compounds available to plants.

84. Explain how a part of a spruce forest burnt out as a result of a forest fire will self-repair.

1) herbaceous photophilous plants develop first;

2) then shoots of birch, aspen, pine appear, the seeds of which fell with the help of the wind, a small-leaved or pine forest is formed;

3) under the canopy of light-loving species, shade-tolerant spruces develop, which will subsequently completely crowd out other trees.

85. Explain the advantage of biological pest control methods over chemical ones.

Biological defense methods are the use of natural enemies. For example, insectivorous birds destroy insect pests.

Pollution of the environment is prevented, while fauna and flora are preserved. After all, the use of pesticides kills not only pests, but all insects.

86. Why is the concentration of oxygen in the lower atmosphere decreasing now?

1) reduction of the green cover of the Earth as a result of deforestation and death of the phytoplankton of the World Ocean due to its pollution;

2) oxygen consumption by vehicles and industry

87. What is the cause of the greenhouse effect?

The greenhouse effect is a process of gradual warming on our planet as a result of an increase in the concentration of anthropogenic impurities in the atmosphere (carbon dioxide, methane, nitrogen oxide, ozone, freons), which, passing the sun's rays, prevent long-wave thermal radiation from the earth's surface. Part of this absorbed thermal radiation is reflected by the atmosphere, returns to the earth's surface and heats the ground layer of air, creating a greenhouse effect. The main source of carbon dioxide of anthropogenic origin is the combustion of coal, oil, gas and other fuels.

88. The mass extermination of wolves in a number of regions has led to a decrease in the number of ungulates, such as deer. How can this be explained?

Wolves play the role of orderlies, destroy sick and weak animals, acting as natural selection. The disappearance of wolves leads to the spread of diseases among ungulates and a decrease in their numbers.

89. Clover grows in the meadow, pollinated by bumblebees. What biotic factors can lead to a decline in the clover population?

Biotic factors - factors of living nature.

1) decrease in the number of bumblebees;

2) an increase in the number of herbivorous animals;

3) reproduction of competing plants (cereals, etc.).

90. A person calmly eats eggs, meat and other foods containing proteins. Why are proteins not injected directly into the bloodstream?

If proteins are injected directly into the blood, then the reaction of rejection of the foreign protein will begin.

91. Why drying fruits keeps them from rotting.

1) for the vital activity of putrefactive bacteria and mold fungi, like other organisms, water is needed;

2) these organisms cannot develop on dried fruits.

92. How does a person use bacteria?

1) in treatment facilities;

2) in everyday life and food industry;

3) in microbiological synthesis;

4) to obtain a number of drugs.

93. How to protect food from rotting?

Food rot is caused by putrefactive bacteria. Their activity and reproduction are inhibited: low temperature, lack of moisture, or the presence of certain substances - preservatives, such as acetic acid, a large amount of salt, etc.

To prevent food from spoiling, they are stored in a frozen, canned, dry form, creating unfavorable conditions for the life of decay bacteria.

94. Why is a temperature rise above 40 ° dangerous for life?

Many proteins act as catalytic enzymes in cells. Enzymes act only at a certain temperature (optimally 38 ° C) and pH of the medium. A prolonged increase in temperature above 38 ° C causes a change in the structure of the enzyme molecule (denaturation), its activity decreases, and then stops. This leads to disruption of the entire metabolism.

At temperatures above 40 ° C, denaturation of proteins, including enzymes, occurs.

95. Why are traits acquired during life not inherited?

Because acquired changes do not affect the genotype

96. What is the purpose of the genealogical method for studying human genetics?

1) to study genealogical families

2) to identify the nature of the study of signs: dominant or recessive

3) to predict the likelihood of hereditary diseases in offspring

97. Why is it important to eat at the same time every day?

When eating food at the same hours in the body, the formation of conditioned juice-releasing reflexes occurs for a while and the food is better digested.

98. Why is it dangerous to eat mushrooms picked near the highway?

Poisonous substances (salts of lead and other heavy metals) accumulate in the bottom, which can cause poisoning and even death.

99. Explain the cause of accumulation of pus in inflammatory processes in tissues.

Pus is formed as a result of the activity of leukocytes, which devour bacteria, foreign bodies and die.

100. What is the reason for rejection of transplanted organs and tissues?

The reason for the rejection of transplanted organs and tissues is the body's immune response to foreign cells and proteins. For the body, transplanted organs are a foreign body. The protective mechanism of immunity comes into force.

101. What explains the changes in the digestive organs, blood composition, and the activity of the nervous system caused by the ox tapeworm in humans?

Bull tapeworm releases toxic substances into the human intestine, they are absorbed into the bloodstream and poison his body.

102. What should be done in order not to get infected with a bull tapeworm, a wide tapeworm?

In order not to get infected with a bovine tapeworm, it is necessary to boil the meat well, but it is better to use meat that has passed a veterinary examination. After all, infected meat (by the Finns - bubbles with the head of a bull tapeworm) is not allowed for sale, sale in the markets.

In order not to get infected with a wide tapeworm, it is necessary to boil well, fry the fish for at least 20 minutes. You can not eat salted, dried at home fish, as well as raw fish.

103. What is the difference between vaccination and therapeutic serum?

1) when vaccinated, a vaccine is introduced into the body (killed or weakened pathogens or their poisons);

2) when vaccinated, the body itself produces protective antibodies;

3) therapeutic serum contains ready-made antibodies.

104. Why are passengers advised to suck on lollipops when taking off or landing an airplane?

1) during takeoff or landing of an aircraft, atmospheric pressure changes rapidly, which causes discomfort in the middle ear, where the initial pressure on the eardrum lasts longer;

2) swallowing movements lead to the opening of the auditory (Eustachian) tube, through which the pressure in the middle ear cavity equalizes with the pressure in the environment.

105. Why do hot shops recommend drinking salted water to quench your thirst?

1) in a person in hot shops, the water-salt balance is disturbed due to the loss of water and mineral salts along with sweat;

2) salted water restores the normal water-salt balance between the tissues and the internal environment of the body.

106. What are the consequences of kidney failure in humans?

1) the chemical composition of the internal environment will change (the concentration of salts will increase, etc.);

2) poisoning of the body with products of protein metabolism.

107. Why can't you take blades of grass in damp meadows?

The larvae of the liver fluke may be on the stems and leaves of plants.

108. Why can't you eat raw, undercooked, or undercooked beef?

The meat may contain ox tapeworm Finns.

109. Describe the path that a drug injected into a vein in the left arm would take if it were to act on the brain.

1) through the veins of the systemic circulation, the drug will enter the right atrium, and then into the right ventricle;

2) from the right ventricle through the vessels of the small circle to the left atrium;

3) from the left atrium to the left ventricle, then along the aorta and carotid artery of a large circle to the brain.

110. According to statistics, smokers are much more likely to suffer from chronic cardiovascular diseases than non-smokers. Explain the effect of toxic substances (carbon monoxide, nicotine) contained in tobacco smoke on the smoker's red blood cells and blood vessels.

1) There is a sharp narrowing of the blood vessels, the blood pressure in them increases.

2) The elasticity of blood vessels decreases, harmful and toxic substances can be deposited on their walls.

3) Carbon monoxide interacts with erythrocytes, resulting in a sharp decrease in the ability of erythrocytes to attach oxygen.

111. The human diet should include not only proteins, fats and carbohydrates, but also vitamins. What explains this?

1) Vitamins are essential for normal metabolism.

2) In the human body, vitamins are practically not formed (some vitamins are formed in small quantities). Therefore, they must be supplied from outside (the main source of vitamins are plants, microorganisms).

112. Why is drug addiction dangerous?

Harmful effects on the cerebral cortex and, consequently, serious disorders of the nervous system. Violations in the cerebral cortex lead to antisocial behavior of people, they become dangerous for society, and not only harm their health.

113. Why is smoking dangerous?

Tobacco contains nicotine and tar, which are harmful factors that affect the nervous system, as well as the body as a whole. The resins contain carcinogens that lead to cancer. Smoking by a pregnant woman can affect the condition of the unborn child, and smoking during adolescence reduces mental alertness and increases fatigue.

Using knowledge of the somatic regulation of the activity of skeletal muscles and the autonomic regulation of internal organs, explain the following hygienic rule: morning exercises should begin with small loads, and then gradually increase them.

114. Calcium salts are removed from donor blood by adding substances that cause these salts to precipitate. Why do they do it?

1) donated blood is transfused to people who need it;

2) calcium ions are involved in the process of blood clotting, so they are removed to prevent clotting.

115. The boy noticed that his visual acuity decreased in low light. What could be the cause of visual impairment?

1) visual acuity in low light depends on the functioning of the rods;

3) the reason for the weakening of vision may be a lack of vitamin A in the diet, this disease is called "night blindness".

116. What is the benefit of blood clotting?

This is a protective mechanism that protects the body from blood loss.

117. How to find out by bleeding which blood vessel is damaged?

If bleeding is characterized by the release of blood over the entire surface of the tissue, it is capillary bleeding, damaged vessels are capillaries.

If the bleeding is characterized by a uniform continuous release of blood in a non-pulsating stream and the color of the blood is dark red, this is venous bleeding, the vein is damaged.

If the bleeding is characterized by the outflow of blood in a fountain-like pulsating jet and the blood is scarlet, it is arterial bleeding, the artery is damaged.

118. Why do muscles feel sore after they work?

Painful sensations in the muscles appear after work, because there is an accumulation of unsplit lactic acid.

119. With prolonged exposure to the sun, a person's skin acquires a brown tint. What is the reason for this and what is its biological significance?

1) darkening of the skin under the action of sunlight is caused by increased accumulation of melanin pigment in the cells of the lower layers of the epithelium;

2) melanin absorbs ultraviolet rays and protects the human body from their harmful effects.

120. Why can the inflammatory process spread from the nasopharynx to the middle ear?

1) Pathogenic microorganisms can get from the nasopharynx to the middle ear through the auditory tube

2) The reproduction of pathogens in the middle ear can lead to an inflammatory process

1) when reading lying down and in a moving vehicle, it is impossible to maintain a constant distance between the eyes and the book.

2) in this case, a violation of the refractive power of the eye occurs, the elasticity of the lens is disturbed.

122. Why is it impossible to keep your mouth closed when making strong, sharp sounds? (why do you have to open your mouth during explosions?)

1) in the middle ear is the auditory tube (Eustachian), which connects the middle ear cavity with the nasopharynx

2) when the mouth is open, the pressure on the eardrum is equalized from the outside and inside

123. Why when we gnaw hard crackers, we hear a deafening noise?

1) the bones of the skull, like all solid and elastic bodies, conduct sounds very well, and sound in a dense medium is amplified

2) therefore, the crackle of cracker, which reached the ear through the air, is perceived as a slight noise, but the same crackle turns into a roar if it reaches the auditory nerve through the hard bones of the skull

124. what first aid should be given to the victim in case of sprain or rupture of ligaments?

1) rest or tight bandaging of the joint

2) cold on the damaged area and deliver to a medical facility

125. How, using a magnet, you can clean the seeds of cultivated plants (for example, flax, clover, alfalfa) from weed seeds?

1) weeds have fleecy seeds that cling to animal hair

2) clogged seeds are sprinkled with iron powder (iron grains stick around weed seeds), and then they are separated with a magnet into clean seeds and weed impurities

Starting from this post, we will analyze which six sections of task group C await your closest consideration and reflection.

C1 — here are tasks that involve applying your knowledge to practical situations . As an USE tutor in biology, I must emphasize that these tasks may relate to any sections of biology.

Here are some examples of tasks C1

All these tasks are from real USE tests in biology of previous years. It is advisable to first answer these questions yourself, preferably in writing, and then compare your answers with the answers at the end of the post:

1. On the surface of the soil, you can sometimes see a large number of earthworms. Explain under what meteorological conditions this occurs and why?

2. Why is the soil in forest plantations populated with mycorrhizal fungi?

3. What processes ensure the movement of water and minerals through the plant?

4. The circulatory system of insects is not associated with the transport of gases. How are they transported through the body of animals?

5. What is the role of chemosynthetic bacteria in ecosystems?

6. What is a conditioned reflex and what is its role in the life of an animal?

7. Ribosomes from different cells, identical mRNA molecules, the necessary set of amino acids and all types of tRNA were placed in a test tube, while creating all the conditions for protein synthesis. Why will one type of protein be synthesized on different ribosomes in a test tube?

8. Explain why the cultivation of legumes does not require top dressing with nitrogen fertilizers?

9. Why can treating a person with antibiotics lead to impaired bowel function?

10. What is the protective role of leukocytes in the human body?

11. Why did plants have tissues and generative organs?

12. What explains the death of seeds in boiled water?

13. What is the meaning of accommodation?

14. Why is only the interconnection of all parts of the analyzer a necessary condition for its functioning?

15. Why is the color of objects not perceived with peripheral vision? Explain the answer.

16. How does the egg develop after fertilization?

17. Why are the testes and ovaries classified as glands of mixed secretion?

18. What determines the intermediate nature of the inheritance of a trait?

19. What is the structure of the vestibular analyzer? Classification of taste buds and their localization.

20. What is the importance of noise control?

21. What first aid measures should not be taken for frostbite of 2-3 degrees and why? What needs to be done?

22. What is the role of plants in ecosystems?

23. It is known that the tail of a male Japanese ornamental rooster reaches 10 meters. Explain how this breed was bred by man. Why are birds with such a long tail not found in nature?

24. When frozen, potato tubers acquire a sweetish taste. What is the reason?

25. Explain from a biological point of view the fact that a person who carries hot tea in a cup made of expensive porcelain does not let go of it and endures pain.

27. At the time of a shootout with bandits, an American cowboy was pierced in the chest from both sides. Although both lungs remained intact, the cowboy still died of asphyxiation. Why?

28. Why, with a bad sense of smell, the taste of food is not felt.

29. What is the difference between experience and observation?

30. Why at a depth of 2000 m under water - animals are not torn apart by pressure?

31. Why is it necessary to pre-emulsify fats to break down fats?

32. Hereditary (congenital) and non-hereditary diseases, the role of the environment in their manifestation?

ANSWERS:

1) usually a lot on the soil surface can be observed after heavy, prolonged rain;

2) earthworms are aerobic organisms, they do not have a specialized respiratory system, they breathe the entire surface of the body with oxygen from the air, therefore they crawl out to the soil surface when their minks are flooded with water.

1) mycorrhizal fungi are symbionts of tree and shrub life forms of plants. They perform the role of root hairs on the roots of these plants;

2) mycorrhizal fungi improve mineral nutrition (mainly phosphorus absorption) and contribute to greater water absorption.

Water and minerals move from the roots to the stem and leaves of the plant through the vessels (ascending xylem current) due to:

1) the sucking power of the roots arising from transpiration - evaporation of water by leaves;

2)root pressure, which occurs as a result of the constant flow of water into the root (diffusion) due to the difference in the concentration of substances in the root cells and the environment.

1) the transport of gases in insects is carried out through specialized respiratory organs - trachea(a system of long thin tubes that surround all organs and tissues);

2) O2 enters the trachea from the air and is transferred to the cells of the insect body, and CO2 is released from the cells in the trachea, so there is no need for the participation of the circulatory system in the transport of gases.

1) are only a small part of the species of prokaryotes (bacteria). These bacteria are able, like plants, to create organic substances from inorganic ones themselves. But unlike plants Photo trophies that use for life sunny energy, these bacteria are chemo trophic organisms (able to use energy for life oxidation of inorganic substances);

2) chemosynthesis bacteria, being, like plants, autotrophic organisms, perform in ecosystems - the creators of primary organic matter, that is, they are the first link in power circuits.

1) conditioned reflexes are reflexes, acquired animals or man during life on the basis of unconditional and not transmitted by inheritance;

2) with the help of conditioned reflexes, the body adapts to specific conditions existence.

1) biological matrix, that is, the primary information for the synthesis of protein molecules are , and ribosomes are just a site for assembling a protein molecule;

2) since i-RNA in the experiment the same - This means that they all carry information about the same primary structure(sequence of amino acid units) of a protein molecule.

1) legumes plants are able to enter symbiotic relationship with nodule bacteria. On the roots of leguminous plants (swellings) are formed, in which bacteria multiply in large numbers;

2) nodule bacteria - . They are able to assimilate plants through the products of photosynthesis molecular nitrogen from the air and convert it into forms available for plant nutrition. Therefore, with effective symbiosis, high yields of legumes are achieved without the use of nitrogen fertilizers.

1) in the human intestine normally develop useful intestinal bacteria. Taking antibiotics can drastically reduce the number of beneficial bacteria;

2) processes will be broken fiber breakdown and water absorption.

Leukocytes are colorless amoeba-like blood cells. They are involved in maintaining immunity, and their role in protecting the body is manifested double way:

1) leukocytes are involved in the production of special immunoglobulin proteins on their surface, which are recognizing and neutralizing foreign antigens;

2) leukocytes are and phagocytes because they are able to absorb and digest foreign substances and cells.

1. Water is a dense, homogeneous medium. Therefore, they do not need either strong mechanical tissues (to give stability to the body in space), or integumentary (preventing the evaporation of water and protection from direct sunlight and temperature changes), or conductive (they can absorb water and minerals with the entire surface of the thallus) . Therefore, the emergence of plants on land and their development of the soil-air environment with different parameters of water and temperature regimes became possible only if all types of tissues were developed.

2. The appearance of specialized organs of sexual reproduction (generative organs) of archegonia and antheridia in mosses, ferns and gymnosperms and flowers in angiosperms was the result of an improvement in adaptability to survival, in the existence of a strict alternation of generations: sporophyte and gametophyte.

1. Seeds swell in water, the embryo “wakes up” and its growth begins. To provide the embryo with energy, it is necessary to oxidize the organic reserve substances of the seed. This process requires the presence of oxygen.

2. Boiled water does not contain oxygen.

1. Accommodation - a change in the curvature of the lens due to the work of the ciliary muscle when viewing objects near and at a distance.
2. Accommodation is necessary in order to focus the image of an object strictly on the retina of the eye (and not in front of the retina, as in myopia - myopia, or behind the retina, as in farsightedness - hypermetropia).

1. Any analyzer consists of three main parts: a receptor, nerve pathways and a center in the cerebral cortex.
With the help of the receptor, the energy of the acting stimulus is converted into a nerve impulse.
2. Conducting nerve pathways carry out the transmission of nerve impulses to the cerebral cortex. These impulses, having reached the cerebral cortex, undergo a certain processing there, leading to the formation of the corresponding “image” of the stimulus. Therefore, only the qualitative interrelation of all parts of the analyzer will ensure the function assigned to it.

1. There are two types of receptor cells: rods and cones. Cones are responsible for color vision and are located mostly closer to the center of the retina. The rods are responsible for the perception of light (that is, black and white perception, which helps us not to bump into objects even at dusk).
2. The rods are located on the retina mainly along its periphery, so we will not be able to clearly characterize the color of an object with peripheral vision.

1. A fertilized egg turns into a zygote. The zygote undergoes rapid divisions (cells do not have time to grow, so this stage is called crushing). Then a single-layer multicellular embryo is formed -.
2. Then - a two-layer embryo - gastrula, a three-layer - neurula.

1. The testicles and ovaries are glands of mixed secretion, like the pancreas, since they are able to form both hormones that enter the bloodstream and substances that are released to the outside.

2. The ovaries secrete eggs into the external environment, and hormones such as estrogen and progesterone into the blood. The testicles secrete spermatozoa into the external environment, and androgens into the blood.

1. any trait manifests itself when one of the allelic genes (denoted by a capital letter, for example, A) does not completely dominate the second allelic gene (denoted by a small letter - a). As a result, heterozygous individuals with the Aa genotype will not be phenotypically similar to the parental individuals.

2. For example, from crossing plants of the night beauty with red flowers (with genotype AA) with a plant with white flowers (with the aa genotype) in the first generation, all Aa heterozygotes will be phenotypically pink. Then in the second generation, from crossing pink heterozygotes with each other, we will get a coincidence of the splitting of the trait by phenotype and genotype: 1:2:1 .

1. The vestibular analyzer consists of the otolithic apparatus and three semicircular canals in the cavity of the inner ear.
2. Taste buds respond to 4 types of substances: a) sour-salty (lateral part of the tongue); b) sweet (tip of the tongue); c) bitter (root of the tongue); d) acute (pain receptors).

1) Noise pollution is the sounds perceived by a person as a hindrance. Depending on the level and activity, noise pollution can cause damage to human health and is one of the environmental problems of the city and industrial premises.
2) Sleep may be disturbed in a person, the productivity of mental activity may decrease, hearing may deteriorate, so the fight against noise will reduce all these adverse effects.

1. In case of frostbite of 2-3 degrees (this is an average and severe degree of frostbite), in no case should rub affected area. In general, it is not necessary to perform any actions that lead to a rapid change in the temperature of the painful place.
2. It is necessary to carefully, trying not to cause additional pain, apply some kind of warming bandage (shawl, scarf, bandage) to the sore spot and by all means take the patient to the hospital as soon as possible.

1. The role of plants in ecosystems, and in fact their overall biospheric role, is determined by the fact that they are in trophic chains (food chains). By creating organic substances from air and water CO2, plants do not waste any energy organic resources of the planet, but carry out this process, called photosynthesis, only due to the energy of solar radiation. All other organisms of all ecosystems: consumers and decomposers - exist only due to the photosynthetic activity of plants.

2. A by-product of photosynthesis is oxygen released into the atmosphere. Once upon a time, the oxygen atmosphere, providing the creation of an ozone screen, contributed to the development of life on land. With the advent of oxygen in the atmosphere, the evolution of living beings on Earth went in the direction of improving the aerobic way of existence, as a more energetically favorable way of development compared to anaerobic existence.

1. The tail of a male Japanese rooster reaches 10 meters, thanks to artificial selection made by a person according to his desire (his whim). How could a man breed such a breed? He probably discovered in any population of chickens an individual that has a mutation in the gene responsible for the formation of the length of the tail (he could also carry out artificial mutagenesis).

2. In natural Under conditions, this mutation, as useless or even harmful for the reproduction of the population (such a rooster will take care of its luxurious property instead of fulfilling its direct natural purpose - caring for chickens) will disappear along with the death of this individual. But under artificial conditions, by producing forced (directed) crosses, one can not only fix, but also strengthen this trait, using the possibilities for the manifestation of the cumulative action of genes.

1. A lot of tasteless starch is stored in potato tubers. Starch is a polysaccharide consisting of monomers - glucose molecules.

2. When frozen, part of the starch is broken down to glucose, which provides the sweetish taste of potatoes.

1. The reaction to pain is unconditional reflex. And if the cup did not have some material or spiritual value for us (high cost or good memory), then we would immediately get rid of the cause of pain.

2. In this case, our pain from the loss of “expensive porcelain” will provide excitation of the area of ​​the cerebral cortex that is responsible for the production conditional reflex. This will lead to braking excitation of the zone that causes the manifestation of the unconditioned reflex.

1. In spring, there is a peak of tick reproduction.

2. Ticks are carriers of a dangerous disease for humans - encephalitis. Outbreaks of the development of encephalitis itself do not occur every year, and usually the population is warned in advance about a suspected outbreak of infection carried by ticks.

1. Inhalation and exhalation are determined by the coordinated work of the intercostal muscles and the diaphragm. This is the only way air can enter and exit the lungs. And the injury could disrupt this process.

2. With such a wound, the cowboy undoubtedly also had a pleural cavity pierced, as a result of which atmospheric pressure compresses the lungs and the person cannot straighten them. No matter how hard he tried to inhale, the air could not get into his lungs, hence the suffocation.

1. If we have a cold and stuffy nose, then we will not be able to taste the food. Everything will seem fresh. In fact, the taste buds are active, but the inability to perceive the smell causes a decrease in taste sensations.

2. Taste analysis performed in the lower parietal lobe of the cerebral cortex is also influenced by olfactory information processed in the adjacent temporal lobe. Many refined flavors owe their existence to the sense of smell.

According to the figurative expression of I.P. Pavlov "... observation collects what nature offers him, while experience takes from nature what he wants." A person observes (at the same time he can describe what he saw) directly what is currently in nature. The experience (or experiment) is planned in advance by him and can be reproduced many times to verify or confirm the hypothesis put forward.

The question is not entirely correct. "Break", if it meant tearing apart from the inside, and animals at depth would have to be flattened and compressed by pressure.

The main "adaptation" of animals to living even at great depths, where the water pressure is really huge, is that all living things are about 70% water (and water, as you know, is almost incompressible even at high pressures). Therefore, inside the body of animals, even at great depths, the pressure will be the same as outside.

It is known that fats are insoluble in water. A process emulsification is only mixing them with an aqueous liquid and creating emulsions. This process occurs under the action of bile. Only such an emulsified state of fats ensures their interaction with lipase- an enzyme that breaks down fats. Lipase is produced by the pancreas and enters (like liver bile) into the duodenum.

Congenital or hereditary diseases associated with the genotype of the organism are present in it even during fertilization. The external environment, as a rule, will not affect their manifestation (a person will get sick even in ideal conditions, but doctors have learned to control a number of hereditary diseases with proper nutrition and patient care). Non-hereditary diseases are those that the body becomes ill under the influence of environmental conditions.

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Who has questions about the article to the USE tutor in biology, comments, wishes - please in the comments, on my blog you can get answers to all tests of the FIPI OBZ for all the years of exams and.

  1. A thin section of a potato tuber was placed in distilled water. What changes will occur in his cells after some time? Explain the answer.
  2. Biological oxidation in the human body is similar in chemical process to the combustion of fuel (coal, peat, wood). What substances are oxidized in the human body and what products common with combustion are formed as a result of these processes?
  3. Explain why in the cells of the muscle tissue of an untrained person after intense physical work there is a feeling of pain.
  4. How is DNA molecular structure different from mRNA?
  5. How, using biochemical analysis, can viruses containing RNA be distinguished from those containing DNA? Give 2 differences.
  6. What is the role of nucleic acids in protein synthesis? How is the transfer of genetic information from the nucleus to the ribosome?
  7. Ribosomes from different cells, the entire set of amino acids and the same molecules of i-RNA and t-RNA were placed in a test tube, creating all the conditions for protein synthesis. Why will one type of protein be synthesized on different ribosomes in a test tube?
  8. Explain why mature erythrocytes cannot synthesize proteins.
  9. What is the nature of most enzymes and why do they lose their activity when radiation levels increase?
  10. Saliva enzymes are active in the mouth but lose their activity in the stomach. How can this be explained?
  11. Freezing of enzymes, in contrast to the action of high temperatures, does not lead to the loss of their activity upon returning to normal conditions. What explains this?
  12. The color of the white hare's coat changes throughout the year: the hare is white in winter and gray in summer. Explain what type of variability is observed in an animal and what determines the manifestation of this trait.
  13. Woody plants growing in areas with a constant wind direction have a flag-shaped crown. Plants grown from cuttings of these trees under normal conditions have a normal crown shape. Explain these phenomena.
  14. From the seeds of one shepherd's purse plant, offspring were raised. The descendants differed from each other and from the parent plant in size, number of flowers and leaves on the shoot. Explain possible reasons for this phenomenon.
  15. Explain the similarities and differences between mutational and combinative variability.
  16. To establish the cause of a hereditary disease, the patient's cells were examined and a change in the length of one of the chromosomes was found. What research method allowed to establish the cause of this disease? What kind of mutation is it associated with?
  17. Patau's syndrome is based on nondisjunction on the 13th pair of chromosomes. The patient's karyotype has 47 chromosomes. Explain what kind of variability is manifested in this syndrome and what method of studying human heredity helped to establish the cause of this disease.
  18. People with sickle cell anemia produce abnormal hemoglobin, which leads to abnormal red blood cells. What kind of mutations are we talking about? Justify the answer.
  19. What causes the birth of a child with Down syndrome? Which method was used to identify its causes?
  20. Why are somatic mutations not transmitted to offspring during sexual reproduction? What organisms can inherit such mutations?
  21. What is the essence of the genealogical method? For what purpose is it used?
  22. What products are formed, and how many ATP molecules are stored in yeast cells during alcoholic fermentation as a result of the breakdown of 15 glucose molecules? Explain the answer.
  23. What systematic group do bacteriophages belong to? What is the peculiarity of their metabolism?
  24. What is the relationship between respiration and photosynthesis?
  25. Explain in what cases only one individual is involved in the process of sexual reproduction. Give examples.
  26. Several whiskers were taken from one strawberry plant, rooted and mature plants were obtained, which were transplanted to another part of the plantation. However, the fruits of some daughter plants turned out to be smaller than on the mother plant. Name the method used to propagate strawberries. Explain the reason for the appearance of small fruits.
  27. A tradescantia plant on one of the shoots had leaves with white spots. When this plant was propagated by seeds, all offspring had green leaves, and the offspring grown from cuttings of shoots with white spots also had leaves with a similar change. Explain this phenomenon using knowledge about patterns of variability.
  28. In some varieties of ornamental plants, double flowers lack stamens and pistils. How are these plant varieties obtained and preserved?
  29. As a result of interspecific crossing of beluga and sterlet fish, an interspecific hybrid, bester, was obtained. This fish is distinguished by valuable nutritional properties, increased vitality. However, besters, like other interspecific animal hybrids, do not produce offspring. Explain why such hybrids are sterile. Is it possible to overcome their infertility?
  30. What selection method can be used to overcome the infertility of plants obtained as a result of distant hybridization, and what is the essence of this method?

To fill the electronic library of the system " 1C: Education» you can use electronic textbooks of the 1C: School series, which cover all levels of general education - from preschool to high school.

1C:School textbooks are published by 1C-Publishing. The 1C-Publishing Publishing House is included in the list of organizations that produce textbooks that are allowed to be used in the implementation of educational programs of general education that have state accreditation (see Order of the Ministry of Education and Science of the Russian Federation No. 699 dated 06/09/2016, line 8 of the Appendix).

1C:School tutorials will help make the lesson bright and dynamic. Interactive and animated drawings, maps and diagrams will increase visibility in the lessons of learning new material, interactive models and dynamic drawings will allow you to conduct an educational study, experiment or laboratory work, interactive practical tasks, simulators and tests - to consolidate your knowledge or check learning outcomes.

List of tutorials

Preschool education

1C: School. Preschool education, 6-7 years

elementary School

1C: School. Mathematics, 1st grade. 1 part

1C: School. Mathematics, 1st grade. part 2

1C: School. Mathematics, 2nd grade.

1C: School. Mathematics, 3rd grade.

1C: School. Mathematics, 4th grade.

1C: School. Mathematics, grades 1-4. Tests.

1C: School. ABC.

1C: School. Russian language, 1st grade.

1C: School. Russian language, grade 3.

1C: School. Russian language, 4th grade.

1C: School. Literary reading, grade 1.

1C: School. Literary reading, grade 2.

1C: School. Literary reading, grade 3.

1C: School. Literary reading, grade 4.

1C: School. Speech development, grades 1–4. Tests.

1C: School. The world around, 1 class.

1C: School. The world around, 2nd grade.

1C: School. The world around, 3rd grade.

1C: School. The world around, 4th grade.

1C: School. The world around, grades 1-4. Tests.

1C: School. Secrets of time and space, grades 1-4.

The world. Interactive maps, grades 1-4.

1C: School. Games and tasks, grades 1–4.

1C: School. Modeling studio. Animals.

Russian language

1C: School. Russian language, grades 5–6. Morphemics. word formation

1C: School. Russian language, grades 5–6. Lexicology.

1C: School. Russian language, grade 5.

1C: School. Russian language, 6th grade.

1C: School. Russian language, 7th grade.

1C: School. Russian language, grade 8.

1C: School. Russian language, grade 9.

1C: School. Punctuation tests, grades 9-11.

Mathematics, algebra, geometry, computer science and ICT

1C: School. Mathematics, 5th grade.

1C: School. Mathematics, 6th grade.

1C: School. Algebra, grades 7–9.

1C: School. Algebraic problems with parameters, grades 9–11.

1C: School. Geometry, 7th grade.

1C: School. Geometry, 8th grade.

1C: School. Geometry, grade 9.

1C: School. Geometry. Interactive tasks for building on a plane, grades 7–10.

1C: School. Geometry. Interactive tasks for building in space, grades 10-11.

Mathematics. Collection of interactive models, grades 5-11.

1C: School. Informatics, 10th grade.

1C: School. Computer science, grade 11.

Natural science and biology

1C: School. Introduction to natural science subjects, Grade 5.

1C: School. Biology, 6th grade.

1C: School. Biology, 7th grade.

1C: School. Biology, 8th grade.

1C: School. Biology, 9th grade.

1C: School. Biology, 10th grade.

1C: School. Biology, 11th grade.

1C: School. Biology, grades 6-9. Breath

1C: School. Biology. Collection of visual materials. 5-11 grades

Biology. Collection of interactive models, grades 9-11.

Geography

1C: School. Geography, grades 7-11. Library of visual aids (preparing for release).

Geography. Interactive maps, grades 6-10.

Physics

1C: School. Physics, 7th grade.

1C: School. Physics, 8th grade.

1C: School. Physics, grade 9.

1C: School. Physics, 10th grade.

1C: School. Physics. Workshop. 7-11 grades.

Economics and social studies

1C: School. Social studies, grades 10–11.

1C: School. Economics, grades 9-11.