Young birch from spring is grown indoors.

4.4. Breeding basics

1.      What is the characteristic of the phenomenon of polyploidy?

ANSWER: A multiple increase in the number of chromosomes.

2.      What is the characteristic of the phenomenon of heterosis?

ANSWER: A striking manifestation of the trait in hybrids of the first generation and their high viability, which disappear in the second generation.

3.      What is the significance of the law of homologous series in the hereditary variability of N.I. Vavilov?

ANSWER: The law makes it possible to predict the presence of similar mutations in related species.

4.      For what purpose is the crossing of individuals of different varieties used in plant breeding?

ANSWER: To obtain combined varieties that combine the useful characteristics of both varieties, i.e. to obtain combinative variability and to obtain the effect of heterosis.

5.      How can a combination of useful traits obtained from crossing two varieties be preserved in plants?

ANSWER: Propagating them vegetatively, since with further crossing, due to the recombination of parental genes, combinations of useful traits in the offspring may disappear.

6.      For what purpose is closely related crossbreeding carried out in breeding. What negative consequences does it have?

ANSWER: With closely related crossing  there is an increase in homozygosity. Closely related crossing (self-pollination in plants) is carried out in order to create clean lines, to fix the trait. But at the same time, harmful recessive genes can also go into a homozygous state, which leads to a decrease in the viability of the offspring or to death.

7.      Why is interline hybridization carried out in plant breeding?

ANSWER: To get the effect of heterosis.

8.      Why does the effect of heterosis appear only in the first generation?

ANSWER: According to scientists, the heterozygosity of the offspring is considered the cause of heterosis. In the second generation, half of the genes become homozygous and the effect is lost.

9.Why are the methods of polyploidy and artificial mutagenesis used in plant breeding not applicable in animal breeding?

ANSWER: This is due to the characteristics of animals: a complex structure (the presence of organ systems), a complex relationship with the environment (nervous system, sensory organs), low fertility compared to plants, prolonged puberty, etc.

10.        What is artificial mutagenesis and what is it used for?

ANSWER: This is the process of artificially obtaining mutations by the action of mutagenic factors (irradiation with ultraviolet and X-rays, etc.) in order to obtain useful mutations in the offspring. Individuals with beneficial mutations further participate in the creation of new strains of microorganisms or plant varieties.

4.5. Fundamentals of Ecology

1.Why do different animals have different fertility?

ANSWER: The more expressed concern for the offspring, the less fertility.

2.      For all organisms, a regularity operates: the greater the probability of the death of the offspring, the greater the fertility.

3.What are the main limiting factors for plants, animals, microorganisms?

ANSWER: For plants: lack of light, water, mineral salts, carbon dioxide.

For animals: lack of food resources, water, unfavorable climatic conditions, parasites, enemies (competitors, predators)

For microorganisms: lack of food resources, unfavorable conditions (temperature, water, gas regime, chemicals (antibiotics for parasites)

4.In which sectors of the national economy are bacteria used?

ANSWER: In the food industry: for the production of drinks, lactic acid products, for fermentation, pickling, winemaking, cheese making; in pharmaceuticals: for the creation of drugs, vaccines; in agriculture: for the preparation of silage, haylage (animal feed), in utilities, in environmental activities: for wastewater treatment, elimination of oil spills, in genetic engineering, microbiology: with the help of them vitamins, hormones, drugs, fodder proteins are obtained etc.

5.Why are there rare and endangered species, if any organism is capable of unlimited growth in numbers?

ANSWER: There are limiting factors that do not allow the restoration of their numbers. Especially human economic activity endangers the existence of many species.

6.What is the essence of the law of limiting factor?

ANSWER: Of all the factors acting on the body, the most important is the one whose value deviates most from the optimal (i.e. the most depressing factor).

7.The schoolchildren took young spruces from the forest and not from the clearing for landscaping the territory. We planted everything correctly, but then the needles turned brown and crumbled. Why?

ANSWER: Shadow and light leaves have differences in structure, are adapted to a certain illumination. After transplanting, the needles could not quickly adjust to bright light and died.

8.Why do plants with a green color live on the surface of water bodies, and red at the depths of the sea?

ANSWER: Not all rays of the light spectrum penetrate to great depths of the seas, but only blue and violet, which are absorbed by red and yellow pigments, so the algae acquire a red color. On the surface, they absorb green chlorophyll pigments.

9.What devices for economical use of water do animal sushi have?

ANSWER: Moving into the shade, digging holes, the horns of reptiles, snail shells, chitinous cover of insects, accumulation of fat as a source of internal water (camels), reducing sweating, saving water when excreting urine and feces, hibernation during the hot season.

10.  Can you call soil a mixture of sand, water, inorganic and organic matter?

ANSWER: No, since there are no living organisms in it and the soil has a certain structure.

11.  Why terrestrial mammals have auricles, while aquatic and soil mammals do not have them or are reduced?

ANSWER: Water and soil have a high density and sounds are well distributed in them.

12.  Why can't you burn last year's grass and plant litter in the spring?

ANSWER: Fires can occur, many insects and invertebrates die, plant seeds and clutches of terrestrial nesting birds are destroyed, shoots of young plants are damaged, their growth slows down, soil erosion increases, and as a result, the ecological balance and natural circulation of substances are destroyed.

13.  Why does a strong "bloom" of water often lead to the death of fish and the death of other inhabitants of the reservoir?

ANSWER: After rapid reproduction, the plants die off, and during rotting, the oxygen of the reservoir is used, which leads to oxygen starvation and the death of its inhabitants, in addition, some blue-green algae release toxic substances. With the oxygen-free decomposition of organic substances, methane, ammonia, hydrogen sulfide are released, which are destructive for all inhabitants.

14.  Why do bog plants (cranberries, wild rosemary), living in high humidity conditions, have a number of features characteristic of plants in arid places (pubescence, waxy bloom, small leathery leaves)?

ANSWER: Swamp water is cold, poorly absorbed by the roots, so it becomes necessary to reduce water evaporation.

15.  What will happen to a young birch if it is grown in room conditions by the window since spring, providing all the care?

ANSWER: In the fall, it will shed its leaves, since leaf fall is an adaptation to changing the length of daylight hours.

16.  Which organisms can enter into symbiosis with which in nature: bee, boletus, sea anemone, oak, birch, hermit crab, aspen, jay, clover, boletus, linden, root nodule bacteria?

ANSWER: Bee — linden, boletus — birch, sea anemone — hermit crab, aspen — aspen, jay — oak, clover — nodule bacteria.

17.  What organisms are human symbionts, their role in the body?

ANSWER: Bacteria and protozoa in the human intestine, which aid in the digestion of fiber, produce some vitamins. In their absence, digestion is disturbed due to dysbiosis.

18.  What is the importance of green plants in fish life?

ANSWER: They enrich water with oxygen, lay eggs on plants, build nests from algae for shelters (stickleback), live among plants, food for herbivorous fish, during mass reproduction in small bodies of water can lead to the death of fish, some aquatic predatory plants (for example, pemphigus) eats fish fry, their caviar.

19.  How can you protect the crop of cultivated plants from pests without the use of pesticides?

ANSWER: 1) Using biological control methods: using parasites and pest predators

(riders, bacteria and viruses, birds, dragonflies, ants, ladybirds). 2) Release into nature sterile (i.e. sterile) male pests (females after mating do not produce offspring. 3) Breeding pest-resistant plant varieties. 4 ) Scaring away granivorous birds, plowing holes of rodents.

20.  What resources are considered exhaustible and non-renewable?

ANSWER: Oil, natural gas, coal, peat, various types of ores (iron, copper, polymetallic, etc.)

21.              Why do pests live more on old, diseased pine trees?

ANSWER: A lot of resin is released on young trees, which contains turpentine, which repels pests.

22.  What will happen on Earth if all organisms die out, except for higher plants?

ANSWER: These plants will also die out, as the biological circulation of substances in nature will disappear.

23.  What plants are carnivores?

ANSWER: Round-leaved sundew (in marshes), common beetle, Venus flytrap, pemphigus common (lives in water). Predatory plants usually live on nitrogen-poor soils and therefore, in the course of evolution, they switched to predation, they have trapping devices.

24.  Why do predators suffer more from herbicide use?

ANSWER: Poisonous substances are usually not excreted from the body and are transferred to the next link, accumulating from link to link. Predators are the last link in the food chain and receive a large dose of harmful substances, which leads to diseases of their body.

25.  What are the advantages and disadvantages of using herbicides against weeds?

ANSWER: BENEFIT: reduce the cost of manual labor, reduce the number of competitors of cultivated plants, increase yields. DISADVANTAGES: poisonous for animals, beneficial insects and humans, expensive production, act only on annual weeds, but perennial rhizomes remain, with repeated use, weeds develop resistance.

26.  What changes can occur if caviar of predatory fish accidentally gets into a reservoir with herbivorous fish?

ANSWER: The caviar may not survive; in the case of survival and development, due to the reproduction of predators, the number of peaceful fish may decrease, but as a result, a certain equilibrium will come in the number of all fish, since all changes in the ecosystem are in the direction of establishing an equilibrium (climax).

27.  Why does the exclusion of protozoa and molluscs from the aquarium ecosystem lead to a sharp disruption of its balance?

ANSWER: Protozoa serve as food for small crustaceans, and those - for fish, and molluscs - self-purify water.

28.  Knowing the 10 percent rule (the ecological pyramid rule), calculate how much phytoplankton is needed to grow one whale weighing 150 tons? (food chain: phytoplankton-zooplankton-whale).

ANSWER: 150,000 x 10 x 10 = 15,000,000 kg (15,000 tons)

29.  If in a forest on an area of ​​1 hectare we weigh separately all plants, all animals separately (insects, amphibians, reptiles, birds, mammals), then the representatives of which group will be the heaviest and lightest in total?

ANSWER: Based on the law of the biomass pyramid, plants will be the heaviest, and predatory vertebrates (i.e., those who are on the last links of the food chain) will be the lightest.

30.  What environmental problems can be considered global for humanity?

ANSWER: Increase in the population of the Earth, pollution of the World Ocean, acid rain, accidents at nuclear power plants, "ozone holes", greenhouse effect (climate change of the planet), deforestation (especially tropical), desertification, reduction of energy resources, air pollution.

31.  What are the advantages and disadvantages of alternative energy sources - solar, wind, ebb and flow, electric?

ANSWER: Advantages: they are free, endless, do not harm the environment.

Disadvantages: they cannot satisfy all energy needs, they cannot be used in all territories, since they depend on the climate and terrain.

32.  Why is the incidence of diseases in trees higher in the city, and the life expectancy is lower?

ANSWER: Increased content of harmful substances in the atmosphere and soil; severe dustiness, impairing photosynthesis; violation of air and water exchange during road construction and paving and trampling; soil salinity; mechanical damage to trees; lack of the required amount of nutrients in the soil due to a violation of the circulation of substances (fallen leaves do not rot, but are collected and taken out).

33.  In winter, salt is used on the roads so that there is no ice. What changes in water bodies and soil does this lead to?

ANSWER: Salt is washed off the roads into water bodies and into the soil, due to an increase in salinity, plants and soil organisms are dehydrated, which leads to their death.

34.  Oil is insoluble in water and slightly toxic. Why is water pollution with oil products considered one of the most dangerous?

ANSWER: A thin oil film impedes gas exchange between water and the atmosphere, because of oxygen starvation, all the inhabitants of the reservoir suffer, especially those living on the surface of the reservoir.

35.  What is the advantage of closed technologies in comparison with the most advanced treatment facilities?

ANSWER: Even the most advanced sewage treatment plants cannot completely clean up sewage and industrial wastewaters. In closed technologies, the water used in production does not enter the environment, therefore it does not pollute it.

36.  Rafting of trees along the rivers is economically very profitable (no need to build roads, waste fuel for transportation). Explain why environmentalists are against such transportation, especially if the trees are not tied into rafts, but are floated one by one?

ANSWER: During such transportation, some of the trees sink, clutter up the banks, settle on the bends of rivers, a large amount of bark and parts of logs fall on the bottom of the river. Sunken trees rot with the consumption of large amounts of oxygen and the release of various toxic substances. This leads to mass death

fish and other inhabitants (especially in summer).

37.  Why is the collection of scrap metal and waste paper considered an important environmental measure?

ANSWER: The secondary use of raw materials reduces its removal from nature, as a result, the negative impact on nature associated with the extraction of raw materials is reduced, raw materials themselves, energy, human labor are saved, and environmental pollution by waste is reduced.

38.  Why is spruce sensitive even to grassroots fires, when only moss, pine needles and grass are burning?

ANSWER: In spruce, the root system is located on the surface, and the lower branches are close to the ground, therefore, the roots are damaged and resinous substances on the branches burn well.

39.  The massive 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?

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

40.  On an area of ​​10 sq. meters out of 700-900 young Christmas trees in 20 years, 2-3 spruce remains. What are the reasons for the decline in numbers and the biological significance of this phenomenon?

ANSWER: Causes of death: intraspecific and interspecific competition, eating by animals, damage by parasites, unfavorable climatic conditions. Biological meaning: "excess" of offspring insures the species from extinction, in the end, the individuals most adapted to these conditions remain.

41.  Scientists believe that overgrazing, frequent fires in the steppe and semi-desert regions of the Earth are the main reason for the desertification of these territories. Explain why?

ANSWER: Frequent fires destroy the vegetation cover, and the organic and mineral substances of the soil turn into a gaseous state and are carried away with the wind, and this impoverishes the soil. When livestock is overgrazed, the plants do not have time to renew and the soil is exposed. These territories are expanding, water and wind erosion is increasing. Open areas heat up faster, evaporation increases, which depletes groundwater and increases soil salinity. In open areas, the direction of air masses changes, precipitation decreases, and the process of desertification is accelerated.

42.  What is the role of pubescence of stems, leaves, fruits and seeds of plants?

ANSWER: The hairs on the leaves and stems protect from drying out by reflecting light, reduce radiation, reduce evaporation, creating a semi-closed layer of air. Coarse hairs and stinging hairs can protect against being eaten (nettles). Pubescent fruits and seeds easily attach to animal hair or are carried away by the wind (dandelion, poplar, etc.)

43.  For what purpose, when progressively planting trees on poor soils, is the soil contaminated with special types of fungi?

ANSWER: These mushrooms entwine the roots of trees with their myceliums - mycorrhiza arises, thanks to which the tree receives water and salts from the huge surface of the soil. The tree does not need to spend a lot of time, substance and energy to create a powerful root system. When this tree is transplanted to a new place, it takes root more easily.

44.  List the resources for which closely related species, like marten and sable, living in the same territory, can compete.

ANSWER: Food (rodents, small birds, etc.), a place for a nest (hollows, old nests of squirrels, crows), hunting territory, shelters, water during a drought.

45.  Closely related species often live together, although it is generally accepted that there is the strongest competition between them. Explain why in these cases there is no complete displacement by one species of the other. Is this contrary to the rule of competitive exclusion?

ANSWER: Displacement does not occur for the following reasons: - closely related species occupy different ecological niches in the same community (different food, method of obtaining food, activity at different times of the day, - excess resource; - the number of a stronger competitor is limited by the third species; - environmental conditions create equilibrium by being favorable to one or the other, so the absence of complete repression does not contradict the rule of competitive exclusion.

46.  It is well known that when making bouquets it is impossible to put roses and carnations, daffodils and forget-me-nots, a rose and mignonette in one vase (flowers wither, lose their aroma). Lilies of the valley in bouquets destroy many plants. Explain why? What is the significance of this phenomenon in plant life?

ANSWER: Plants secrete phytoncides - volatile substances that inhibit or have a detrimental effect on other organisms. This allows them to outperform the competition.

47.  Among forest birds and mammals, the most sharp fluctuations are observed in the number of seed-eating animals - crossbills, squirrels, nutcrackers, and mice. Explain why?

ANSWER: It depends on how the abundance of food changes from year to year. Trees do not give a bountiful harvest every year, but with interruptions of 4-12 years. In lean years, mass mortality and migration of animals is observed, their fertility decreases.

48.  What organisms in the ecosystem close the cycle of substances in the ecosystem, decomposing organic matter?

ANSWER: Reducers.

49.  Why is the relationship between elk and bison in the mixed forest ecosystem considered a competition?

ANSWER: They eat the same food.

50.  What factors contribute to the regulation of the number of wolves in the ecosystem?

ANSWER: Anthropogenic, lack of herbivores (food), pathogens, intraspecific and interspecific competition.

51.  What are the causes of wet smog in large cities?

ANSWER: High content of pollutants, dust, smoke and humid windless weather in the air.

52.  Hives with bees are often placed on buckwheat fields. What is the significance of this event in plant life?

ANSWER: Bees feed on buckwheat pollen and nectar, carry out cross-pollination, which increases the yield of buckwheat. A person receives a double benefit: a large harvest of buckwheat and buckwheat honey.

53.  Why the number of commercial herbivorous fish can sharply decrease when predatory fish are destroyed in the reservoir?

ANSWER: The destruction of predatory fish leads to a sharp increase in the number of herbivorous fish and increased competition between them. This leads to a decrease in the food supply, the spread of various diseases, which will lead to the mass death of fish.

54.  To combat insect pests, humans use chemicals. Explain how the life of an oak forest can change if all herbivorous insects are destroyed by a chemical method.

ANSWER: Since herbivorous insects are mostly pollinators, their destruction will lead to a sharp decline in the number of insect pollinated plants. This can lead to a decrease in the number or disappearance of second-order consumers (insectivores). Chemical substances that have got into the soil can lead to disruption of the vital activity of plants, the death of soil microflora and fauna. All this can lead to serious disturbances in the ecological balance and even to the death of the oak grove.

55.  Why are owls in the forest ecosystem referred to as consumers of the 2nd order, and mice as consumers of the 1st order?

ANSWER: Mice feed on plants and owls feed on mice. The 1st order consumables are herbivorous, and the 2nd order consumables feed on herbivorous animals.

56.  As a result of the forest fire, part of the spruce forest burned out. Explain how it will heal itself.

ANSWER: The first to develop are herbaceous light-loving plants. Then shoots of birch, aspen, pine appear, the seeds of which were caught by the wind, a small-leaved forest is formed. Under the canopy of light-loving trees, shade-tolerant spruces develop, which subsequently completely replace other types of trees.

57.  What is the basis for the formation of diverse food networks in ecosystems?

ANSWER: The food network is formed from a variety of interconnected food chains, which means that its diversity is based on the diversity of species, the presence of producers, consumers, decomposers among them and the variety of their food (broad food specialization).

58.  What are the properties of biogeocenosis?

ANSWER: Biogeocenosis is an open, self-regulating system that is stable, capable of metabolism and energy. Biogeocenosis is a part of the biosphere. It consists of an abiotic and biotic component, characterized by productivity, biomass, population density, its constituents, and a variety of species. The living components of the biogeocenosis are producers, consumers and decomposers, thanks to which a continuous circulation of substances and energy conversion takes place in it.

59.  What are the features of the biosphere as the shell of the Earth?

ANSWER: Biogeochemical processes take place in the biosphere, the geological activity of organisms is manifested; there is a continuous process of circulation of substances, regulated by the activity of organisms; the biosphere converts the energy of the Sun into the energy of organic substances.

60.  What is the difference between the ground-air environment and the water environment?

ANSWER: There is more oxygen in the ground-air environment, temperature fluctuations can occur in it over a wide range, it has a lower density and more illumination

61.  Why does biomass generally decrease from link to link in the terrestrial food chain?

ANSWER: The food chain includes producers, consumers and decomposers. In each link, most of the organic matter (about 90%) is broken down to inorganic substances, and they are released into the environment. The energy released in this case is spent on vital activities, turns into heat energy and dissipates into the environment. Thus, the biomass decreases from link to link. This pattern is called the 10% rule or the ecological pyramid rule.

62.  Why is it necessary to maintain biodiversity to conserve the biosphere?

ANSWER: Biodiversity is the backbone of the diverse food chains and webs in the ecosystems of the biosphere. And the variety of food chains and networks is the basis for a balanced cycle of substances, preserving the integrity of the biosphere. A balanced circulation of substances is the basis for stability, self-regulation and preservation of the biosphere.

63.  VI Vernadsky wrote: "On the earth's surface there is no chemical force that is more constantly acting, and therefore more powerful in its ultimate consequences, than living organisms taken as a whole." Explain what changes have occurred in the lithosphere due to the vital activity of living organisms?

ANSWER: Formation of soil, destruction of rocks (for example, lichens that secrete organic acids), the formation of a number of minerals (for example, coal and brown coal, iron-containing ores, peat, limestone, etc.).

64.  Make up the food chain and determine the 2nd order consumer using all the named representatives: hawk, apple flowers, great tit, apple blossom beetle.

ANSWER: Apple flowers - - apple blossom beetle - great tit - hawk. 2nd order consummation - great tit.

65.  What is the relationship between producers and reducers that are part of any ecosystem?

ANSWER: Producers create organic matter from inorganic, and decomposers use organic residues and mineralize them, providing producers with minerals.

66.  Why is the oxygen concentration decreasing in the lower atmosphere?

ANSWER: This happens because the area of ​​the Earth's vegetation is reduced due to deforestation, the phytoplankton of the World Ocean is killed due to its pollution, oxygen consumption increases during the combustion of fuels (vehicles, industry, etc.)

67.  Why are the cells of the body dehydrated during anabiosis of the body at low temperatures?

ANSWER: At negative temperatures, the water inside the cell turns into ice. Ice crystals damage cellular structures, which causes the death of the body.

68.  Explain why the pond frog is active during the day, and the grass frog is active at dusk and in the morning?

ANSWER: Drying out the skin is dangerous for the frog. The pond frog is constantly near the reservoir, therefore it is active during the day, and the grass frog is far from it, and therefore is active during the humid periods of the day - in the morning and in the evening.

69. Why are dark-colored reptiles more common in cold regions, and light-colored reptiles in the southern regions?

ANSWER: Reptiles are cold-blooded and their activity depends on the ambient temperature. The dark color absorbs heat better, so in the cold zones the reptiles are dark-colored, in the south they are light-colored.

70. What factors affect the self-cleaning of the reservoir?

ANSWER: The oxygen content (the more it is, the faster the dead organic matter decomposes), the speed of the flow (the faster the flow, the more oxygen in the water), the presence of animals that feed by filtering the water (bivalve molluscs).

71. Meadows that grow in the forest zone and are left to their own devices quickly become overgrown with forest.However, in places of constant farming, this does not happen. Why?

ANSWER: In places of agriculture, the soil is trampled down, compacted, the undergrowth of trees is destroyed.

72. How can the phenomena of predation and parasitism be used in agriculture?

ANSWER: To protect cultivated plants from insect pests as a method of biological control of them.

73. Why are pine pests more common on diseased trees and bypass young and healthy pines?

ANSWER: Young pines emit a lot of resin, and the turpentine, which is part of the resin, repels and kills pests.

74. In some ponds, ducks are bred to increase the growth of carp. Why?

ANSWER: Duck droppings promote the growth of algae and invertebrates that carp feed on.

75.  Why in August in the coniferous forest under the trees you can see a lot of fallen needles, and in the deciduous forest there are almost no fallen leaves? How does this affect soil fertility?

ANSWER: The needles contain many resinous substances that impede their decomposition by microorganisms. In addition, in the coniferous forest, under shade conditions, the temperature is lower and the decomposition rate is low. Due to the slow decomposition and leaching of organic matter, the soil in the coniferous forest contains little humus.

76.  The food chains of natural biogeocenoses include producers, consumers and decomposers. What role do the organisms of these groups play in the circulation of substances and the conversion of energy?

ANSWER: Producers - produce organic substances from inorganic ones during photosynthesis or chemosynthesis. They contain the energy necessary for the life of other organisms. These include plants, blue-green bacteria, and chemosynthetic bacteria. Consumables - they consume ready-made organic substances, but do not bring them to mineralization. Reducers - in the course of life, they convert organic residues to mineral ones and close the circulation of substances. They use the energy released at the same time for life.

77.  What determines the sustainability of natural ecosystems?

ANSWER: The number of species, the number of links in food chains and their complex interweaving, self-regulation and self-renewal.

78.  In some forest biocenoses, daytime birds of prey were mass-shot to protect chickens. Explain how this event affected the number of chickens.

ANSWER: Due to the lack of natural regulators of the number, at first the number of chickens increases. Then it sharply decreases due to the lack of food resources and the rapid spread of diseases due to the high density of individuals.

79.  To preserve and increase fish stocks, certain fishing rules have been established. Explain why fine mesh nets and fishing techniques such as pickling or jamming fish with explosives should not be used when fishing. (2 points)

ANSWER: when using fine-mesh nets, a lot of undergrown fish is caught, which could give large offspring; etching or jamming with explosives - predatory fishing methods in which a lot of fish die uselessly

80.  To combat insect pests, humans use chemicals. Indicate at least 3 changes in the life of the oak forest if all herbivorous insects are chemically destroyed in it. Explain why they will happen.

ANSWER: 1) The number of insect pollinated plants will sharply decrease, since herbivorous insects are pollinators of plants. 2) 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 get into the soil, and will lead to disruption of the vital activity of plants, the death of soil flora and fauna, all violations can lead to the death of the oak forest.

1.Why do different animals have different fertility?

ANSWER:The more expressed concern for the offspring, the less fertility.

2.For all organisms, a regularity operates: the greater the probability of the death of the offspring, the greater the fertility.

3. What are the main limiting factors for plants, animals, microorganisms?

ANSWER:For plants: lack of light, water, mineral salts, carbon dioxide.

For animals: lack of food resources, water, unfavorable climatic conditions, parasites, enemies (competitors, predators)

For microorganisms: lack of food resources, unfavorable conditions (temperature, water, gas regime, chemicals (antibiotics for parasites)

4. In which sectors of the national economy are bacteria used?

ANSWER:In the food industry: for the production of drinks, lactic acid products, for fermentation, pickling, winemaking, cheese making; in pharmaceuticals: for the creation of drugs, vaccines; in agriculture: for the preparation of silage, haylage (animal feed), in utilities, in environmental activities: for wastewater treatment, elimination of oil spills, in genetic engineering, microbiology: with the help of them vitamins, hormones, medicines, fodder proteins are obtained etc.

5. Why are there rare and endangered species, if any organism is capable of unlimited growth in numbers?

ANSWER:There are limiting factors that do not allow the restoration of their numbers. Especially human economic activity endangers the existence of many species.

6. What is the essence of the law of limiting factor?

ANSWER:Of all the factors acting on the body, the most important is the one whose value deviates most from the optimal (i.e. the most depressing factor).

7. The schoolchildren took young spruces from the forest and not from the clearing for landscaping the territory. We planted everything correctly, but then the needles turned brown and crumbled. Why?

ANSWER:Shadow and light leaves have differences in structure, are adapted to a certain illumination. After transplanting, the needles could not quickly adjust to bright light and died.

8. Why do plants with a green color live on the surface of water bodies, and red ones at the depths of the sea?

ANSWER:Not all rays of the light spectrum penetrate to great depths of the seas, but only blue and violet, which are absorbed by red and yellow pigments, so the algae acquire a red color. On the surface, they absorb green chlorophyll pigments.

9. What kind of water saving devices do animal sushi have?

ANSWER:Moving into the shade, digging holes, the horns of reptiles, snail shells, chitinous cover of insects, accumulation of fat as a source of internal water (camels), reducing sweating, saving water when excreting urine and feces, hibernation during the hot season.

10. Can you call soil a mixture of sand, water, inorganic and organic substances?

ANSWER:No, since there are no living organisms in it and the soil has a certain structure.

11. Why terrestrial mammals have auricles, while aquatic and soil mammals do not have them or are reduced?

ANSWER:Water and soil have a high density and sounds are well distributed in them.

12. Why is it impossible to burn last year's grass and plant litter in the spring?

ANSWER:Fires can occur, many insects and invertebrates die, plant seeds and clutches of terrestrial nesting birds are destroyed, shoots of young plants are damaged, their growth slows down, soil erosion increases, and as a result, the ecological balance and natural circulation of substances are destroyed.

13. Why does a strong "bloom" of water often lead to the death of fish and the death of other inhabitants of the reservoir?

ANSWER:After rapid reproduction, the plants die off, and during rotting, the oxygen of the reservoir is used, which leads to oxygen starvation and the death of its inhabitants, in addition, some blue-green algae release toxic substances.With the oxygen-free decomposition of organic substances, methane, ammonia, hydrogen sulfide are released, which are destructive for all inhabitants.

14. Why do bog plants (cranberries, wild rosemary), living in high humidity conditions, have a number of features characteristic of plants in arid places (pubescence, waxy bloom, small leathery leaves)?

ANSWER:Swamp water is cold, poorly absorbed by the roots, so it becomes necessary to reduce water evaporation.

15. What will happen to a young birch, if it is grown in room conditions by the window since spring, providing all the care?

ANSWER:In the fall, it will shed its leaves, since leaf fall is an adaptation to changing the length of daylight hours.

16. Which organisms can enter into symbiosis with which in nature: bee, boletus, sea anemone, oak, birch, hermit crab, aspen, jay, clover, boletus, linden, root nodule bacteria?

ANSWER:Bee — linden, boletus — birch, sea anemone — hermit crab, aspen — aspen, jay — oak, clover — nodule bacteria.

17. What organisms are human symbionts, their role in the body?

ANSWER:Bacteria and protozoa in the human intestine, which aid in the digestion of fiber, produce some vitamins. In their absence, digestion is disturbed due to dysbiosis.

18. What is the importance of green plants in the life of fish?

ANSWER:They enrich water with oxygen, lay eggs on plants, build nests from algae for shelters (stickleback), live among plants, food for herbivorous fish, during mass reproduction in small reservoirs can lead to the death of fish, some aquatic predatory plants (for example, pemphigus) eats fish fry, their caviar.

19. How can crop crops be protected from pests without the use of pesticides?

ANSWER:1) Using biological control methods: the use of parasites and pest predators

(riders, bacteria and viruses, birds, dragonflies, ants, ladybirds). 2) Release into nature sterile (i.e. sterile) male pests (females after mating do not give offspring. 3) Breeding pest-resistant plant varieties. 4 ) Scaring away granivorous birds, plowing holes of rodents.

20. What resources are considered exhaustible and non-renewable?

ANSWER:Oil, natural gas, coal, peat, various types of ores (iron, copper, polymetallic, etc.)

21. Why do pests live more on old, diseased pine trees?

ANSWER:A lot of resin is released on young trees, which contains turpentine, which repels pests.

22. What will happen on Earth if all organisms die out, except for higher plants?

ANSWER: These plants will also die out, as the biological circulation of substances in nature will disappear.

23. What plants are carnivores?

ANSWER:Round-leaved sundew (in marshes), common beetle, Venus flytrap, pemphigus common (lives in water). Predatory plants usually live on nitrogen-poor soils and therefore, in the course of evolution, they switched to predation, they have trapping devices.

24. Why do predators suffer more from the use of herbicides?

ANSWER:Poisonous substances are usually not excreted from the body and are transferred to the next link, accumulating from link to link. Predators are the last link in the food chain and receive a large dose of harmful substances, which leads to diseases of their body.

25. What are the advantages and disadvantages of using herbicides against weeds?

ANSWER:BENEFIT: reduce the cost of manual labor, reduce the number of competitors of cultivated plants, increase yields. DISADVANTAGES: poisonous for animals, beneficial insects and humans, expensive production, act only on annual weeds, but perennial rhizomes remain, with repeated use, weeds develop resistance.

26. What changes can occur if caviar of predatory fish accidentally gets into a reservoir with herbivorous fish?

ANSWER:The caviar may not survive; in the case of survival and development, due to the reproduction of predators, the number of peaceful fish may decrease, but as a result, a certain equilibrium will come in the number of all fish, since all changes in the ecosystem are in the direction of establishing an equilibrium (climax).

27. Why does the exclusion of protozoa and molluscs from the aquarium ecosystem lead to a sharp disruption of its balance?

ANSWER:Protozoa serve as food for small crustaceans, and those - for fish, and molluscs - self-purify water.

28. Knowing the 10 percent rule (the ecological pyramid rule), calculate how much phytoplankton is needed to grow one whale weighing 150 tons? (food chain: phytoplankton-zooplankton-whale).

ANSWER:150,000 x 10 x 10 = 15,000,000 kg (15,000 tons)

29. If in a forest on an area of ​​1 hectare we weigh separately all plants, all animals separately (insects, amphibians, reptiles, birds, mammals), then the representatives of which group will be the heaviest and lightest in total?

ANSWER:Based on the law of the biomass pyramid, plants will be the heaviest, and predatory vertebrates (i.e., those who are on the last links of the food chain) will be the lightest.

30. What environmental problems can be considered global for humanity?

ANSWER:Increase in the population of the Earth, pollution of the World Ocean, acid rain, accidents at nuclear power plants, "ozone holes", greenhouse effect (climate change of the planet), deforestation (especially tropical), desertification, reduction of energy resources, air pollution.

31. What are the advantages and disadvantages of alternative energy sources - solar, wind, ebb and flow, electric?

ANSWER:Advantages: they are free, endless, do not harm the environment.

Disadvantages: they cannot satisfy all energy needs, they cannot be used in all territories, since they depend on the climate and terrain.

32. Why is the incidence of diseases in trees higher in the city, and less in life expectancy?

ANSWER:Increased content of harmful substances in the atmosphere and soil; severe dustiness, impairing photosynthesis; violation of air and water exchange during road construction and paving and trampling; soil salinity; mechanical damage to trees; lack of the required amount of nutrients in the soil due to a violation of the cycle of substances (fallen leaves do not rot, but are collected and taken out).

33. In winter, salt is used on the roads so that there is no ice. What changes in water bodies and soil does this lead to?

ANSWER:Salt is washed off the roads into water bodies and into the soil, due to an increase in salinity, plants and soil organisms are dehydrated, which leads to their death.

34. Oil is insoluble in water and slightly toxic. Why is water pollution with oil products considered one of the most dangerous?

ANSWER:A thin oil film interferes with gas exchange between water and the atmosphere; due to oxygen starvation, all the inhabitants of the reservoir suffer, especially those living on the surface of the reservoir.

35. What is the advantage of closed technologies in comparison with the most advanced treatment facilities?

ANSWER:Even the most advanced sewage treatment plants cannot completely clean up sewage and industrial wastewaters. In closed technologies, the water used in production does not enter the environment, therefore it does not pollute it.

36. Rafting of trees on rivers is very profitable economically (no need to build roads, waste fuel for transportation). Explain why environmentalists are against such transportation, especially if the trees are not tied into rafts, but are floated one by one?

ANSWER:During such transportation, some of the trees sink, clutter up the banks, settle on the bends of rivers, a large amount of bark and parts of logs fall on the bottom of the river. Sunken trees rot with the consumption of large amounts of oxygen and the release of various toxic substances.This leads to mass death

fish and other inhabitants (especially in summer).

37. Why is the collection of scrap metal and waste paper considered an important environmental measure?

ANSWER:The secondary use of raw materials reduces its removal from nature, as a result, the negative impact on nature associated with the extraction of raw materials is reduced, raw materials themselves, energy, human labor are saved, and environmental pollution by waste is reduced.

38. Why is spruce sensitive even to grassland fires, when only moss, pine needles and grass are burning?

ANSWER:In spruce, the root system is located on the surface, and the lower branches are close to the ground, therefore, the roots are damaged and resinous substances on the branches burn well.

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

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

40. On an area of ​​10 sq. meters out of 700-900 young Christmas trees in 20 years, 2-3 spruce remains. What are the reasons for the decline in numbers and the biological significance of this phenomenon?

ANSWER: Causes of death: intraspecific and interspecific competition, eating by animals, damage by parasites, unfavorable climatic conditions. Biological meaning: "excess" of offspring insures the species from extinction, in the end, the individuals most adapted to these conditions remain.

41. Scientists believe that overgrazing, frequent fires in the steppe and semi-desert regions of the Earth are the main reason for the desertification of these territories. Explain why?

ANSWER: Frequent fires destroy the vegetation cover, and the organic and mineral substances of the soil turn into a gaseous state and are carried away with the wind, and this impoverishes the soil. When livestock is overgrazed, the plants do not have time to renew and the soil is exposed. These territories are expanding, water and wind erosion is increasing. Open areas heat up faster, evaporation increases, which depletes groundwater and increases soil salinity. In open areas, the direction of air masses changes, precipitation decreases, and the process of desertification is accelerated.

42. What is the role of pubescence of stems, leaves, fruits and seeds of plants?

ANSWER: The hairs on leaves and stems protect from drying out by reflecting light, reduce radiation, reduce evaporation, creating a semi-closed layer of air. Coarse hairs and stinging hairs can protect against being eaten (nettles). Pubescent fruits and seeds easily attach to animal hair or are carried away by the wind (dandelion, poplar, etc.)

43. For what purpose is the soil contaminated with special types of fungi during the progressive planting of trees on poor soils?

ANSWER:These fungi entwine the roots of trees with their myceliums - mycorrhiza arises, thanks to which the tree receives water and salts from the huge surface of the soil. The tree does not need to spend a lot of time, substance and energy to create a powerful root system. When this tree is transplanted to a new place, it takes root more easily.

1. What is the characteristic of the phenomenon of polyploidy?

ANSWER: A multiple increase in the number of chromosomes.

2. What is the characteristic of the phenomenon of heterosis?

ANSWER: A striking manifestation of the trait in hybrids of the first generation and their high viability, which disappear in the second generation.

3. What is the significance of the law of homologous series in the hereditary variability of N.I. Vavilov?

ANSWER: The law makes it possible to predict the presence of similar mutations in related species.

4. For what purpose is the crossing of individuals of different varieties used in plant breeding?

ANSWER: To obtain combined varieties that combine the useful characteristics of both varieties, i.e. to obtain combinative variability and to obtain the effect of heterosis.

5. How can a combination of useful traits obtained from crossing two varieties be preserved in plants?

ANSWER: By propagating them vegetatively, since with further crossing, due to the recombination of parental genes, combinations of useful traits in the offspring may disappear.

6. For what purpose is closely related crossbreeding carried out in breeding. What negative consequences does it have?

ANSWER: With closely related crossing there is an increase in homozygosity. Closely related crossing (self-pollination in plants) is carried out in order to create clean lines, to fix the trait. But at the same time, harmful recessive genes can also go into a homozygous state, which leads to a decrease in the viability of the offspring or to death.

7. Why is interline hybridization carried out in plant breeding?

ANSWER: To get the effect of heterosis.

8. Why does the effect of heterosis appear only in the first generation?

ANSWER: According to scientists, the heterozygosity of the offspring is considered the cause of heterosis. In the second generation, half of the genes become homozygous and the effect is lost.

9. Why are the methods of polyploidy and artificial mutagenesis used in plant breeding not applicable in animal breeding?

ANSWER: This is due to the characteristics of animals: a complex structure (the presence of organ systems), a complex relationship with the environment (nervous system, sensory organs), low fertility compared to plants, prolonged puberty, etc.

10. What is artificial mutagenesis and what is it used for?

ANSWER: This is the process of artificially obtaining mutations by the action of mutagenic factors (irradiation with ultraviolet and X-rays, etc.) in order to obtain useful mutations in the offspring. Individuals with beneficial mutations further participate in the creation of new strains of microorganisms or plant varieties.

4.5. Fundamentals of Ecology

1. Why do different animals have different fertility?

ANSWER: The more expressed concern for the offspring, the less fertility.

2. For all organisms, a regularity operates: the greater the probability of the death of the offspring, the greater the fertility.

3. What are the main limiting factors for plants, animals, microorganisms?

ANSWER: For plants: lack of light, water, mineral salts, carbon dioxide.

For animals: lack of food resources, water, unfavorable climatic conditions, parasites, enemies (competitors, predators)

For microorganisms: lack of food resources, unfavorable conditions (temperature, water, gas regime, chemicals (antibiotics for parasites)

4. In which sectors of the national economy are bacteria used?

ANSWER: In the food industry: for the production of drinks, lactic acid products, for fermentation, pickling, winemaking, cheese making; in pharmaceuticals: for the creation of drugs, vaccines; in agriculture: for the preparation of silage, haylage (animal feed), in utilities, in environmental activities: for wastewater treatment, elimination of oil spills, in genetic engineering, microbiology: with the help of them vitamins, hormones, drugs, fodder proteins are obtained etc.

5. Why are there rare and endangered species, if any organism is capable of unlimited growth in numbers?

ANSWER: There are limiting factors that do not allow the restoration of their numbers. Especially human economic activity endangers the existence of many species.

6. What is the essence of the law of limiting factor?

ANSWER: Of all the factors acting on the body, the most important is the one whose value deviates most from the optimal (i.e. the most depressing factor).

7. The schoolchildren took young spruces from the forest and not from the clearing for landscaping the territory. We planted everything correctly, but then the needles turned brown and crumbled. Why?

ANSWER: Shadow and light leaves have differences in structure, are adapted to a certain illumination. After transplanting, the needles could not quickly adjust to bright light and died.

8. Why do plants with a green color live on the surface of reservoirs, and red at the depths of the sea?

ANSWER: Not all rays of the light spectrum penetrate to great depths of the seas, but only blue and violet, which are absorbed by red and yellow pigments, so the algae acquire a red color. On the surface, they absorb green chlorophyll pigments.

9. What devices for economical use of water do animal sushi have?

ANSWER: Moving to the shade, digging holes, reptile horns, snail shells, insect chitinous cover, accumulation of fat as a source of internal water (camels), reducing sweating, saving water when excreting urine and feces, hibernation during the hot season.

10. Can you call soil a mixture of sand, water, inorganic and organic matter?

ANSWER: No, since there are no living organisms in it and the soil has a certain structure.

11. Why terrestrial mammals have auricles, while aquatic and soil mammals do not have them or are reduced?

ANSWER: Water and soil have a high density and sounds are well distributed in them.

12. Why not burn last year's grass and plant litter in the spring?

ANSWER: Fires can occur, many insects and invertebrates die, plant seeds and clutches of terrestrial nesting birds are destroyed, shoots of young plants are damaged, their growth slows down, soil erosion increases, and as a result, the ecological balance and natural circulation of substances are destroyed.

13. Why does a strong "bloom" of water often lead to the death of fish and the death of other inhabitants of the reservoir?

ANSWER: After rapid reproduction, the plants die off, and during rotting, the oxygen of the reservoir is used, which leads to oxygen starvation and the death of its inhabitants, in addition, some blue-green algae release toxic substances. With the oxygen-free decomposition of organic substances, methane, ammonia, hydrogen sulfide are released, which are destructive for all inhabitants.

14. Why do bog plants (cranberries, wild rosemary), living in high humidity conditions, have a number of features characteristic of plants in arid places (pubescence, waxy bloom, small leathery leaves)?

ANSWER: Swamp water is cold, poorly absorbed by the roots, so it becomes necessary to reduce water evaporation.

15. What will happen to a young birch if it is grown in room conditions by the window since spring, providing all the care?

ANSWER: In the fall, it will shed its leaves, since leaf fall is an adaptation to changing the length of daylight hours.

16. Which organisms can enter into symbiosis with which in nature: bee, boletus, sea anemone, oak, birch, hermit crab, aspen, jay, clover, boletus, linden, root nodule bacteria?

ANSWER: Bee — linden, boletus — birch, sea anemone — hermit crab, aspen — aspen, jay — oak, clover — nodule bacteria.

17. What organisms are human symbionts, their role in the body?

ANSWER: Bacteria and protozoa in the human gut that aid in the digestion of fiber produce certain vitamins. In their absence, digestion is disturbed due to dysbiosis.

18. What is the importance of green plants in fish life?

ANSWER: They enrich water with oxygen, lay eggs on plants, build nests from algae for shelters (stickleback), live among plants, food for herbivorous fish, during mass reproduction in small bodies of water can lead to the death of fish, some aquatic predatory plants (for example, pemphigus) eats fish fry, their caviar.

19. How can you protect the crop of cultivated plants from pests without the use of pesticides?

ANSWER: 1) Using biological control methods: using parasites and pest predators

(riders, bacteria and viruses, birds, dragonflies, ants, ladybirds). 2) Release into nature sterile (i.e. sterile) male pests (females after mating do not produce offspring. 3) Breeding pest-resistant plant varieties. 4 ) Scaring off granivorous birds, plowing holes of rodents.

20. What resources are considered exhaustible and non-renewable?

ANSWER: Oil, natural gas, coal, peat, various types of ores (iron, copper, polymetallic, etc.)

21. Why do pests live more on old, diseased pine trees?

ANSWER: A lot of resin is released on young trees, which contains turpentine, which repels pests.

22. What will happen on Earth if all organisms die out, except for higher plants?

ANSWER: These plants will also die out, as the biological circulation of substances in nature will disappear.

23. What plants are carnivores?

ANSWER: Round-leaved sundew (in marshes), common beetle, Venus flytrap, pemphigus common (lives in water). Predatory plants usually live on nitrogen-poor soils and therefore, in the course of evolution, they switched to predation, they have trapping devices.

24. Why do predators suffer more from herbicide use?

ANSWER: Poisonous substances are usually not excreted from the body and are transferred to the next link, accumulating from link to link. Predators are the last link in the food chain and receive a large dose of harmful substances, which leads to diseases of their body.

25. What are the advantages and disadvantages of using herbicides against weeds?

ANSWER: BENEFIT: reduce the cost of manual labor, reduce the number of competitors of cultivated plants, increase yields. DISADVANTAGES: poisonous for animals, beneficial insects and humans, expensive production, act only on annual weeds, but perennial rhizomes remain, with repeated use, weeds develop resistance.

26. What changes can occur if caviar of predatory fish accidentally gets into a reservoir with herbivorous fish?

ANSWER: The caviar may not survive; in the case of survival and development, due to the reproduction of predators, the number of peaceful fish may decrease, but as a result, a certain balance will come in the number of all fish, since in the ecosystem all changes are in the direction of establishing an equilibrium (climax).

27. Why does the exclusion of protozoa and molluscs from the aquarium ecosystem lead to a sharp disruption of its balance?

ANSWER: Protozoa serve as food for small crustaceans, and those - for fish, and molluscs - self-purify water.

28. Knowing the 10 percent rule (the ecological pyramid rule), calculate how much phytoplankton is needed to grow one whale weighing 150 tons? (food chain: phytoplankton-zooplankton-whale).

ANSWER: 150,000 x 10 x 10 = 15,000,000 kg (15,000 tons)

29. If in a forest on an area of ​​1 hectare we weigh separately all plants, all animals separately (insects, amphibians, reptiles, birds, mammals), then the representatives of which group will be the heaviest and lightest in total?

ANSWER: Based on the law of the biomass pyramid, plants will be the heaviest, and predatory vertebrates (i.e., those who are on the last links of the food chain) will be the lightest.

30. What environmental problems can be considered global for humanity?

ANSWER: Increase in the population of the Earth, pollution of the World Ocean, acid rain, accidents at nuclear power plants, "ozone holes", greenhouse effect (climate change of the planet), deforestation (especially tropical), desertification, reduction of energy resources, air pollution.

31. What are the advantages and disadvantages of alternative energy sources - solar, wind, ebb and flow, electric?

ANSWER: Advantages: they are free, endless, do not harm the environment.

Disadvantages: they cannot satisfy all energy needs, they cannot be used in all territories, since they depend on the climate and terrain.

32. Why is the incidence of diseases in trees higher in the city, and the life expectancy is lower?

ANSWER: Increased content of harmful substances in the atmosphere and soil; severe dustiness, impairing photosynthesis; violation of air and water exchange during road construction and paving and trampling; soil salinity; mechanical damage to trees; lack of the required amount of nutrients in the soil due to a violation of the cycle of substances (fallen leaves do not rot, but are collected and taken out).

33. In winter, salt is used on the roads so that there is no ice. What changes in water bodies and soil does this lead to?

ANSWER: Salt is washed off the roads into water bodies and into the soil, due to an increase in salinity, plants and soil organisms are dehydrated, which leads to their death.

34. Oil is insoluble in water and slightly toxic. Why is water pollution with oil products considered one of the most dangerous?

ANSWER: A thin oil film interferes with gas exchange between water and the atmosphere; due to oxygen starvation, all the inhabitants of the reservoir suffer, especially those living on the surface of the reservoir.

35. What is the advantage of closed technologies in comparison with the most advanced treatment facilities?

ANSWER: Even the most advanced sewage treatment plants cannot completely purify sewage and industrial wastewaters. In closed technologies, the water used in production does not enter the environment, therefore it does not pollute it.

36. Rafting of trees along the rivers is economically very profitable (no need to build roads, waste fuel for transportation). Explain why environmentalists are against such transportation, especially if the trees are not tied into rafts, but are floated one by one?

ANSWER: During such transportation, some of the trees sink, clutter up the banks, settle on the bends of rivers, a large amount of bark and parts of logs fall on the bottom of the river. Sunken trees rot with the consumption of large amounts of oxygen and the release of various toxic substances. This leads to mass death

fish and other inhabitants (especially in summer).

37. Why is the collection of scrap metal and waste paper considered an important environmental measure?

ANSWER: The secondary use of raw materials reduces its removal from nature, as a result, the negative impact on nature associated with the extraction of raw materials is reduced, raw materials themselves, energy, human labor are saved, and environmental pollution by waste is reduced.

38. Why is spruce sensitive even to grassroots fires when only moss, pine needles and grass are burning?

ANSWER: In spruce, the root system is located on the surface, and the lower branches are close to the ground, therefore, the roots are damaged and resinous substances on the branches burn well.

39. The massive 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?

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

40. On an area of ​​10 sq. meters out of 700-900 young Christmas trees in 20 years, 2-3 spruce remains. What are the reasons for the decline in numbers and the biological significance of this phenomenon?

ANSWER:Causes of death: intraspecific and interspecific competition, eating by animals, damage by parasites, unfavorable climatic conditions. Biological meaning: "excess" of offspring insures the species from extinction, in the end, the individuals most adapted to these conditions remain.

41. Scientists believe that overgrazing, frequent fires in the steppe and semi-desert regions of the Earth are the main reason for the desertification of these territories. Explain why?

ANSWER:Frequent fires destroy the vegetation cover, and the organic and mineral substances of the soil turn into a gaseous state and are carried away with the wind, and this impoverishes the soil. When livestock is overgrazed, the plants do not have time to renew and the soil is exposed. These territories are expanding, water and wind erosion is increasing. Open areas heat up faster, evaporation increases, which depletes groundwater and increases soil salinity. In open areas, the direction of air masses changes, precipitation decreases, and the process of desertification is accelerated.

42. What is the role of pubescence of stems, leaves, fruits and seeds of plants?

ANSWER:The hairs on leaves and stems protect from drying out by reflecting light, reduce radiation, reduce evaporation, creating a semi-closed layer of air. Coarse hairs and stinging hairs can protect against being eaten (nettles). Pubescent fruits and seeds easily attach to animal hair or are carried away by the wind (dandelion, poplar, etc.)

43. For what purpose, when progressively planting trees on poor soils, is the soil contaminated with special types of fungi?

ANSWER: These fungi entwine the roots of trees with their myceliums - mycorrhiza arises, thanks to which the tree receives water and salts from the huge surface of the soil. The tree does not need to spend a lot of time, substance and energy to create a powerful root system. When this tree is transplanted to a new place, it takes root more easily.

44. List the resources for which closely related species, like marten and sable, living in the same area, can compete.

ANSWER:Food (rodents, small birds, etc.), a place for a nest (hollows, old nests of squirrels, crows), hunting territory, shelters, water during a drought.

45. Closely related species often live together, although it is generally accepted that there is the strongest competition between them. Explain why in these cases there is no complete displacement by one species of the other. Is this contrary to the rule of competitive exclusion?

ANSWER: Displacement does not occur for the following reasons: - closely related species occupy different ecological niches in the same community (different food, method of obtaining food, activity at different times of the day, - excess resource; - the number of a stronger competitor is limited by the third species; - environmental conditions create equilibrium by being favorable for one or the other, so the absence of complete repression does not contradict the rule of competitive exclusion.

46. It is well known that when making bouquets it is impossible to put roses and carnations, daffodils and forget-me-nots, a rose and mignonette in one vase (flowers wither, lose their aroma). Lilies of the valley in bouquets destroy many plants. Explain why? What is the significance of this phenomenon in plant life?

ANSWER: Plants secrete phytoncides - volatile substances that inhibit or have a detrimental effect on other organisms. This allows them to outperform the competition.

47. Among forest birds and mammals, the most sharp fluctuations are observed in the number of seed-eating animals - crossbills, squirrels, nutcrackers, and mice. Explain why?

ANSWER: It depends on how the abundance of food changes from year to year. Trees do not give a bountiful harvest every year, but with interruptions of 4-12 years. In lean years, mass mortality and migration of animals is observed, their fertility decreases.

48. What organisms in the ecosystem close the cycle of substances in the ecosystem, decomposing organic matter?

ANSWER: Reducers.

49. Why is the relationship between elk and bison in the mixed forest ecosystem considered a competition?

ANSWER: They eat the same food.

50. What factors contribute to the regulation of the number of wolves in the ecosystem?

ANSWER: Anthropogenic, lack of herbivores (food), pathogens, intraspecific and interspecific competition.

51. What are the causes of wet smog in large cities?

ANSWER: High content of pollutants, dust, smoke and humid windless weather in the air.

52. Hives with bees are often placed on buckwheat fields. What is the significance of this event in plant life?

ANSWER: Bees feed on buckwheat pollen and nectar, carry out cross-pollination, which increases the yield of buckwheat. A person receives a double benefit: a large harvest of buckwheat and buckwheat honey.

53. Why the number of commercial herbivorous fish can sharply decrease when predatory fish are destroyed in the reservoir?

ANSWER: The destruction of predatory fish leads to a sharp increase in the number of herbivorous fish and increased competition between them. This leads to a decrease in the food supply, the spread of various diseases, which will lead to the mass death of fish.

54. To combat insect pests, humans use chemicals. Explain how the life of an oak forest can change if all herbivorous insects are destroyed by a chemical method.

ANSWER: Since herbivorous insects are mostly pollinators, their destruction will lead to a sharp decline in the number of insect pollinated plants. This can lead to a decrease in the number or disappearance of second-order consumers (insectivores). Chemical substances that have got into the soil can lead to disruption of the vital activity of plants, the death of soil microflora and fauna. All this can lead to serious disturbances in the ecological balance and even to the death of the oak grove.

55. Why are owls in the forest ecosystem referred to as consumers of the 2nd order, and mice as consumers of the 1st order?

ANSWER: Mice feed on plants and owls feed on mice. The 1st order consumables are herbivorous, and the 2nd order consumables feed on herbivorous animals.

56. As a result of the forest fire, part of the spruce forest burned out. Explain how it will heal itself.

ANSWER: The first to develop are herbaceous light-loving plants. Then shoots of birch, aspen, pine appear, the seeds of which were caught by the wind, a small-leaved forest is formed. Under the canopy of light-loving trees, shade-tolerant spruces develop, which subsequently completely replace other types of trees.

57. What is the basis for the formation of diverse food networks in ecosystems?

ANSWER: The food network is formed from a variety of interconnected food chains, which means that its diversity is based on the diversity of species, the presence of producers, consumers, decomposers among them and the variety of their food (broad food specialization).

58. What are the properties of biogeocenosis?

ANSWER: Biogeocenosis is an open, self-regulating system that is stable, capable of metabolism and energy. Biogeocenosis is a part of the biosphere. It consists of an abiotic and biotic component, characterized by productivity, biomass, population density, its constituents, and a variety of species. The living components of the biogeocenosis are producers, consumers and decomposers, thanks to which a continuous circulation of substances and energy conversion takes place in it.

59. What are the features of the biosphere as the shell of the Earth?

ANSWER: Biogeochemical processes take place in the biosphere, the geological activity of organisms is manifested; there is a continuous process of circulation of substances, regulated by the activity of organisms; the biosphere converts the energy of the Sun into the energy of organic substances.

60. What is the difference between the ground-air environment and the water environment?

ANSWER: There is more oxygen in the ground-air environment, temperature fluctuations can occur in it over a wide range, it has a lower density and more illumination

61. Why does biomass generally decrease from link to link in the terrestrial food chain?

ANSWER: The food chain includes producers, consumers and decomposers.In each link, most of the organic matter (about 90%) is broken down to inorganic substances, and they are released into the environment. The energy released in this case is spent on vital activities, turns into heat energy and dissipates into the environment. Thus, the biomass decreases from link to link. This pattern is called the 10% rule or the ecological pyramid rule.

62. Why is it necessary to maintain biodiversity to conserve the biosphere?

ANSWER: Biodiversity is the backbone of the diverse food chains and webs in the ecosystems of the biosphere. And the variety of food chains and networks is the basis for a balanced cycle of substances, preserving the integrity of the biosphere. A balanced circulation of substances is the basis for stability, self-regulation and preservation of the biosphere.

63. VI Vernadsky wrote: "On the earth's surface there is no chemical force that is more constantly acting, and therefore more powerful in its final consequences than living organisms taken as a whole." Explain what changes have occurred in the lithosphere due to the vital activity of living organisms?

ANSWER: Formation of soil, destruction of rocks (for example, lichens that secrete organic acids), the formation of a number of minerals (for example, coal and brown coal, iron-containing ores, peat, limestone, etc.).

64. Make up the food chain and determine the 2nd order consumer using all the named representatives: hawk, apple flowers, great tit, apple blossom beetle.

ANSWER: Apple flowers - - apple blossom beetle - great tit - hawk. 2nd order consummation - great tit.

65. What is the relationship between producers and reducers that are part of any ecosystem?

ANSWER: Producers create organic matter from inorganic, and decomposers use organic residues and mineralize them, providing producers with minerals.

66. Why is the oxygen concentration decreasing in the lower atmosphere?

ANSWER: This happens because the area of ​​the Earth's vegetation is reduced due to deforestation, the phytoplankton of the World Ocean is killed due to its pollution, oxygen consumption increases during the combustion of fuels (vehicles, industry, etc.)

67. Why are the cells of the body dehydrated during anabiosis of the body at low temperatures?

ANSWER: At negative temperatures, the water inside the cell turns into ice. Ice crystals damage cellular structures, which causes the death of the body.

68. Explain why the pond frog is active during the day, and the grass frog is active at dusk and in the morning?

ANSWER: Drying out the skin is dangerous for the frog. The pond frog is constantly near the reservoir, therefore it is active during the day, and the grass frog is far from it, and therefore is active during the humid periods of the day - in the morning and in the evening.

69. Why are dark-colored reptiles more common in cold regions, and light-colored reptiles in the southern regions?

ANSWER: Reptiles are cold-blooded and their activity depends on the ambient temperature. The dark color absorbs heat better, so in the cold zones the reptiles are dark-colored, in the south they are light-colored.

70. What factors affect the self-cleaning of the reservoir?

ANSWER: The oxygen content (the more it is, the faster the dead organic matter decomposes), the speed of the flow (the faster the flow, the more oxygen in the water), the presence of animals that feed by filtering the water (bivalve molluscs).

71. Meadows that grow in the forest zone and are left to their own devices quickly overgrow with forest. However, in places of constant farming, this does not happen. Why?

ANSWER: In places of agriculture, the soil is trampled down, compacted, the undergrowth of trees is destroyed.

72. How can the phenomena of predation and parasitism be used in agriculture?

ANSWER: To protect cultivated plants from insect pests as a method of biological control of them.

73. Why are pine pests more often found on diseased trees and bypass young and healthy pines?

ANSWER: Young pines emit a lot of resin, and the turpentine, which is part of the resin, repels and kills pests.

74. In some ponds, ducks are bred to increase the growth of carp. Why?

ANSWER: Duck droppings promote the growth of algae and invertebrates that carp feed on.

75. Why in August in the coniferous forest under the trees you can see a lot of fallen needles, and in deciduous forest last year's fallen leaves are almost none? How does this affect fertility soil?

ANSWER: The needles contain many resinous substances that make them difficult to decompose by microorganisms. In addition, in coniferous forests, in conditions of shade, the temperature is lower and the decomposition rate is slow. Due to the slow decomposition and leaching of organic matter, the soil in the coniferous forest contains little humus.

76. The food chains of natural biogeocenoses include producers, consumers and decomposers. What role do the organisms of these groups play in the circulation of substances and the conversion of energy?

ANSWER: Producers - produce organic substances from inorganic ones during photosynthesis or chemosynthesis. They contain the energy necessary for the life of other organisms. These include plants, blue-green bacteria, and chemosynthetic bacteria. Consumables - they consume ready-made organic substances, but do not bring them to mineralization. Reducers - in the course of life, they convert organic residues to mineral ones and close the circulation of substances. They use the energy released at the same time for life.

77. What determines the sustainability of natural ecosystems?

ANSWER: The number of species, the number of links in food chains and their complex interweaving, self-regulation and self-renewal.

78. In some forest biocenoses, daytime birds of prey were mass-shot to protect chickens. Explain how this event affected the chicken population.

ANSWER:Due to the lack of natural regulators of the number, at first the number of chickens increases. Then it sharply decreases due to the lack of food resources and the rapid spread of diseases due to the high density of individuals.

79. To preserve and increase fish stocks, certain fishing rules have been established. Explain why fine mesh nets and fishing techniques such as pickling or jamming fish with explosives should not be used when fishing. (2 points)

ANSWER:when using fine-mesh nets, a lot of undergrown fish is caught, which could give large offspring; etching or jamming with explosives - predatory fishing methods in which a lot of fish die uselessly

80. To combat insect pests, humans use chemicals. Indicate at least 3 changes in the life of the oak forest if all herbivorous insects are chemically destroyed in it. Explain why they will happen.

ANSWER: 1) The number of insect pollinated plants will sharply decrease, since herbivorous insects are pollinators of plants. 2) Insectivorous organisms (consumers of the II order) will sharply decrease or disappear due to disruption of food chains. 3) Part of the chemicals used to kill insects will get into the soil, and will lead to disruption of the vital activity of plants, the death of soil flora and fauna, all violations can lead to the death of the oak forest.