Lesson type - combined
Methods: partially search, problem presentation, reproductive, explanatory and illustrative.
Target: mastering the ability to apply biological knowledge in practical activities, use information about modern achievements in the field of biology; work with biological devices, tools, reference books; conduct observations of biological objects;
Tasks:
Educational: the formation of cognitive culture, mastered in the process of educational activities, and aesthetic culture as the ability to have an emotional and value-based attitude towards objects of living nature.
Educational: development of cognitive motives aimed at obtaining new knowledge about living nature; cognitive qualities of a person associated with mastering the fundamentals of scientific knowledge, mastering methods of studying nature, and developing intellectual skills;
Educational: orientation in the system of moral norms and values: recognition of the high value of life in all its manifestations, the health of one’s own and other people; environmental consciousness; nurturing love for nature;
Personal: understanding of responsibility for the quality of acquired knowledge; understanding the value of adequately assessing one’s own achievements and capabilities;
Cognitive: ability to analyze and evaluate the impact of environmental factors, risk factors on health, the consequences of human activities in ecosystems, the impact of one’s own actions on living organisms and ecosystems; focus on continuous development and self-development; the ability to work with various sources of information, transform it from one form to another, compare and analyze information, draw conclusions, prepare messages and presentations.
Regulatory: the ability to organize independent completion of tasks, evaluate the correctness of work, and reflect on one’s activities.
Communicative: the formation of communicative competence in communication and cooperation with peers, understanding the characteristics of gender socialization in adolescence, socially useful, educational and research, creative and other types of activities.
Technologies : Health conservation, problem-based, developmental education, group activities
Types of activities (content elements, control)
Formation in students of activity abilities and abilities to structure and systematize the subject content being studied: collective work - study of text and illustrative material, compilation of a table “Systematic groups of multicellular organisms” with the advisory assistance of student experts, followed by self-test; pair or group performance of laboratory work with the advisory assistance of a teacher, followed by mutual testing; independent work on the studied material.
Planned results
Subject
understand the meaning of biological terms;
describe the structural features and basic life processes of animals of different systematic groups; compare the structural features of protozoa and multicellular animals;
recognize organs and organ systems of animals of different systematic groups; compare and explain reasons for similarities and differences;
establish the relationship between the structural features of organs and the functions they perform;
give examples of animals of different systematic groups;
distinguish the main systematic groups of protozoa and multicellular animals in drawings, tables and natural objects;
characterize the directions of evolution of the animal world; provide evidence of the evolution of the animal world;
Metasubject UUD
Cognitive:
work with different sources of information, analyze and evaluate information, transform it from one form to another;
draw up theses, various types of plans (simple, complex, etc.), structure educational material, give definitions of concepts;
carry out observations, perform elementary experiments and explain the results obtained;
compare and classify, independently choosing criteria for the specified logical operations;
build logical reasoning, including establishing cause-and-effect relationships;
create schematic models highlighting the essential characteristics of objects;
identify possible sources of necessary information, search for information, analyze and evaluate its reliability;
Regulatory:
organize and plan your educational activities - determine the purpose of the work, the sequence of actions, set tasks, predict the results of the work;
independently put forward options for solving assigned tasks, anticipate the final results of the work, choose the means to achieve the goal;
work according to plan, compare your actions with the goal and, if necessary, correct mistakes yourself;
master the basics of self-control and self-assessment for making decisions and making informed choices in educational, cognitive and educational and practical activities;
Communicative:
listen and engage in dialogue, participate in collective discussion of problems;
integrate and build productive interactions with peers and adults;
adequately use verbal means for discussion and argumentation of one’s position, compare different points of view, argue one’s point of view, defend one’s position.
Personal UUD
Formation and development of cognitive interest in the study of biology and the history of the development of knowledge about nature
Techniques: analysis, synthesis, inference, translation of information from one type to another, generalization.
Basic Concepts
Concepts: biocenosis, layering, producers, consumers, decomposers, agrobiocenosis; stability of biocenoses, reasons for stability, comparison of natural and artificial biocenosis
During the classes
Updating knowledge ( concentration when learning new material)
Choose the correct answer in your opinion
1. Which of the following applies to artificial biocenoses?
field
2. What is the name of the set of populations that make up the biocenoa?
species diversity
dominants
biomass
3. What is the vertical spatial division of a biocenosis called?
tiering
layering
mosaic
4. What components does the biocenosis consist of?
producers and consumers
consumers and decomposers
producers, decomposers and consumers
5. What are the names of the components of a biocenosis - organisms capable of producing organic substances from inorganic ones?
producers
consumers
decomposers
6. What are the names of heterotrophs, organisms that consume ready-made organic substances created by autotrophs?
producers
consumers
decomposers
7. What are the names of organisms that destroy dead remains of living beings, turning them into inorganic and simple organic compounds?
decomposers
consumers
producers
8. What are predatory heterotrophs called?
consumers of the first order
second-order consumers
third-order consumers
9. Which of these organisms is a decomposer?
mushroom
10. Who is a second-order consumer?
eagle
mouse vole
Learning new material(teacher's story with elements of conversation)
Artificial biocenoses and their characteristics: agrocenosis, urbacenosis, technocenosis
Artificial biocenoses are created, maintained and managed by humans. Professor B. G. Ioganzen introduced into ecology the concept of anthropocenosis, that is, a natural system artificially created by people, for example, a public garden, terrarium or aquarium. Among artificial biocenoses, agrobiocenoses (agrocenoses) are distinguished - communities created by man to obtain any products.
These include:
reservoirs;
channels;
ponds;
drained swamps;
pastures;
fields for growing various crops;
forest shelterbelts;
artificially regenerated forest plantations.
The characteristic features of agrocenoses are:
Such artificial systems are ecologically quite unstable, and without human participation, agrocenoses of vegetable and grain crops will last about a year, agrobiocenoses of perennial grasses will last about three years. The most stable biocenoses are artificial fruit crops, since without human influence they can exist for several decades.
agrophytocenosis as the basis of life activity;
lack of self-regulation of the system;
low species diversity;
dominance of domestic animals or cultivated plants;
receiving additional support from humans (weed and pest control, fertilization, etc.);
the impossibility of long-term existence without human participation.
However, it should be noted that even the poorest agrocenoses in species diversity contain dozens of species of organisms belonging to various ecological and systematic groups. Any field sown by humans with fodder or agricultural crops is a biocenosis inhabited by various living organisms. Examples are a field of rye or wheat, where, in addition to the main crop, weeds also “live”; and various insects (both pests and their antagonists); and a variety of microorganisms and invertebrates.
Urbanecosystems- ecosystems of human settlements. By their structure, these are complex systems containing, in addition to residential buildings themselves, structures that serve people (industrial enterprises, transport and roads, parks, etc.). A significant portion of the world's population lives in cities (about 75%). The process of increasing the number of urban settlements, leading to the growth and development of cities, is called urbanization. A large city changes almost all components of the natural environment - the atmosphere, vegetation, soil, relief, hydrographic network, groundwater, soils and even climate. Climatic conditions in cities differ significantly from surrounding areas. Differences in temperature, relative humidity, and solar radiation between the city and its surroundings are sometimes comparable to movement in natural conditions by 20° latitude. The meteorological regime of the city is influenced by the following factors: a change in the albedo (reflectivity) of the earth's surface leads to heating of buildings and structures in the city and the formation of a “heat island”.
The average air temperature in a big city is usually 1-2 higher than the temperature of the surrounding areas, at night - 6-8 ° C; within the city, wind speed noticeably decreases, which leads to the formation of pockets with high concentrations of pollutants in the air; pollution of the atmosphere with various impurities contributes to the formation of anthropogenic aerosol, which leads to a sharp decrease in the amount of solar radiation (insolation) reaching the earth's surface by 15%, ultraviolet radiation - by an average of 30%, and contributes to an increase in the frequency of fogs - on average by 2-5 times, an increase in cloudiness and the likelihood of precipitation.
Increased rainfall over the city is to the detriment of other areas, increasing the aridity of the countryside; a decrease in the average amount of evaporation from the earth's surface leads to a significant decrease in air humidity in winter by 2%, in summer by 20-30%.
The problem of modern large cities is aggravated by a sharp lack of natural and spatial resources. Therefore, great importance should be given to urban planning issues. The planning of populated areas (urban planning) is understood as a branch of architecture that considers the issues of comprehensive organization of living space at the level of regions, groups of populated areas and individual cities and towns. In recent years, a direction of environmental planning has emerged in which environmental requirements dominate - ecological architecture.
Ecological architecture strives to take into account as much as possible the environmental and socio-ecological needs of a particular person from birth to old age. Modern forms of spatial organization and concentration of production make it possible to isolate the most aggressive economic objects in relation to the natural environment and humans, and to make valuable natural complexes more accessible.
For this purpose, functional zones are developed.
Residential (residential) zone designed to accommodate residential areas, public centers (administrative, scientific, educational, medical, etc.), green spaces. It prohibits the construction of industrial, transport and other enterprises that pollute the human environment. The residential area is located on the windward side for the prevailing winds, as well as upstream of the rivers in relation to industrial and agricultural enterprises with technological processes that are a source of release of harmful and unpleasant-smelling substances into the environment. In areas with opposite directions of prevailing winds in the summer and winter periods of the year, residential areas are located to the left and right of the indicated wind directions in relation to industrial enterprises.
Industrial Zone intended to accommodate industrial enterprises and related facilities. Industrial zones are formed taking into account production, technological, transport, sanitary, hygienic and functional requirements. The most hazardous enterprises, including explosive and fire hazardous ones, are located away from the residential area, and on the leeward side, i.e. in such a way that the prevailing winds blow from the residential area to the industrial area. Industrial zones with enterprises that pollute the water surface are located along the river below the residential and recreational areas. To improve the processes of dispersing emissions into the atmosphere, enterprises are located at higher elevations, thereby increasing the actual height of emissions. On the contrary, enterprises with contaminated industrial sites should be located at lower elevations than residential areas and recreation areas in order to avoid washing off pollution by stormwater into residential areas.
Sanitary protection zone designed to reduce the negative impact of industrial and transport facilities on the population. This zone of space and vegetation is specifically allocated between industrial enterprises and the residential area. The sanitary protection zone provides space for the safe dispersion of hazardous industrial waste. The width of the sanitary protection zone is determined and calculated on the basis of scientific materials on the pattern of distribution of air pollution, the presence of self-purification processes in the atmosphere, as well as the norms of maximum permissible concentrations of pollutants.
In accordance with environmental requirements, at least 40% of the sanitary protection zone must be landscaped.
Communal and warehouse area designed to accommodate commercial warehouses, warehouses for storing vegetables and fruits, transport service enterprises (depots, car parks), consumer service enterprises (laundry factories and dry cleaning factories), etc. The communal and warehouse zone is located outside the residential area, often in the sanitary protection zones of industrial enterprises. The external transport zone serves to accommodate transport communications of passenger and freight railway stations, ports, marinas, etc.
It is recommended that residential buildings in cities and other populated areas be separated from railway lines by a sanitary protection zone 100 m wide, from the edge of the roadway of highways and freight roads to the red line of residential buildings by at least 50 m, or additional noise barriers or forest belts should be constructed. The recreation area includes city and district parks, forest parks, sports complexes, beaches, holiday villages, resorts, and tourism sites.
A special place among the possible impacts in modern residential areas is occupied by impacts associated with changes in physical parameters.
Physical pollution- this is pollution caused by changes in the physical parameters of the environment: temperature and energy (thermal), wave (light, noise and electromagnetic pollution), radiation (radiation and radioactive pollution).
Thermal pollution formed when humans use additional energy from fossil fuels. Under the influence of additional heat, changes occur in the hydrochemical composition of groundwater (soil salinization), disruption of microbiological and soil-absorbing complexes, degradation and changes in the species composition of vegetation.
With increasing temperature in the body of humans and animals, there is an acceleration of the absorption of harmful substances and their entry into the blood, which leads to the rapid development of a toxic process, increasing sensitivity to the toxic effects of poisons, disruption of metabolism, and the functional state of the nervous system. Light pollution is the brightening of the night sky by artificial light sources whose light is scattered in the lower atmosphere. This phenomenon is sometimes also called light smog.
Light pollution affects the growth and development cycle of many plants. Common sources of white light with a large proportion of spectral blue light interfere with the orientation of many species of nocturnal insects, and also lead astray migratory birds trying to fly around the centers of civilization. The effects of light pollution on the chronobiology of the human body have not been fully studied. There may be deviations in hormonal balance, which is closely related to the perceived day-night cycle.
Noise pollution. Natural sounds do not affect human environmental well-being: the rustling of leaves and the measured noise of the sea surf correspond to approximately 20 dB. Sound discomfort is created by anthropogenic noise sources with high (more than 60 dB) noise levels, which cause numerous complaints. The permissible traffic noise near the walls of houses should not exceed 50 dB during the day and 40 dB at night, and the general noise level in residential premises should not exceed 40 dB during the day and 30 dB at night.
To reduce noise along the path of its propagation, various measures are used: organizing the necessary territorial breaks, rational planning and development of the territory, using the terrain as natural screens, noise-protective landscaping.
Electromagnetic pollution. Electromagnetic fields (EMF) are one of the constant elements of the human environment and all living beings, under which the centuries-old evolution of organisms took place.
Thus, during periods of magnetic storms, the number of cardiovascular diseases increases. Constant magnetic fields in everyday life are created by various industrial installations, some devices, etc.
To ensure sanitary and hygienic standards for the quality of the urban environment, it is necessary to create an ecological framework - a system of combined and interconnecting natural areas of various sizes, the inextricable interconnection of which allows maintaining ecological balance and the living environment, biological diversity.
The basis of this frame is green spaces.
Green plants play a huge role in enriching the environment with oxygen and absorbing the resulting carbon dioxide.
The World Health Organization (WHO) believes that per 1 city dweller there should be 50 m2 of urban green spaces and 300 m2 of suburban ones. Green spaces improve the microclimate of urban areas, protect the soil, building walls, and sidewalks from excessive overheating, increase air humidity, trap dust particles, precipitate fine aerosols, and absorb gaseous pollutants.
Many plants secrete phytoncides - volatile substances that can kill pathogenic bacteria or inhibit their development. They protect the surrounding areas well from noise impacts. They have a beneficial effect on a person’s mental and emotional state.
: Animals. Kp. for the teacher: From work experience, -M.:, Education. Molis S. S.. Molis S. A
Work program in biology 7th grade for teaching materials V.V. Latyushina, V.A. Shapkina (M.: Bustard).
V.V. Latyushin, E. A. Lamekhova. Biology. 7th grade. Workbook for the textbook by V.V. Latyushina, V.A. Shapkina “Biology. Animals. 7th grade". - M.: Bustard.
Zakharova N. Yu. Tests and tests in biology: to the textbook by V. V. Latyushin and V. A. Shapkin “Biology. Animals. 7th grade” / N. Yu. Zakharova. 2nd ed. - M.: Publishing house "Exam"
Presentation hosting
Biocenosis (from the Greek bios - life, koinos - general) is an organized group of interconnected populations of plants, animals, fungi and microorganisms living together in the same environmental conditions.
The concept of “biocenosis” was proposed in 1877 by the German zoologist K. Moebius. Moebius, studying oyster banks, came to the conclusion that each of them represents a community of living beings, all members of which are closely interconnected. Biocenosis is a product of natural selection. Its survival, stable existence in time and space depends on the nature of the interaction of the constituent populations and is possible only with the obligatory supply of radiant energy from the Sun from outside.
Each biocenosis has a certain structure, species composition and territory; it is characterized by a certain organization of food connections and a certain type of metabolism
But no biocenosis can develop on its own, outside and independently of the environment. As a result, certain complexes, collections of living and nonliving components, develop in nature. The complex interactions of their individual parts are supported on the basis of versatile mutual adaptability.
A space with more or less homogeneous conditions, inhabited by one or another community of organisms (biocenosis), is called a biotope.
In other words, a biotope is a place of existence, habitat, biocenosis. Therefore, a biocenosis can be considered as a historically established complex of organisms, characteristic of a specific biotope.
Any biocenosis forms a dialectical unity with a biotope, a biological macrosystem of an even higher rank - a biogeocenosis. The term “biogeocenosis” was proposed in 1940 by V. N. Sukachev. It is almost identical to the term “ecosystem”, widely used abroad, which was proposed in 1935 by A. Tansley. There is an opinion that the term “biogeocoenosis” to a much greater extent reflects the structural characteristics of the macrosystem being studied, while the concept of “ecosystem” primarily includes its functional essence. In fact, there is no difference between these terms. Undoubtedly, V.N. Sukachev, formulating the concept of “biogeocoenosis”, combined in it not only the structural, but also the functional significance of the macrosystem. According to V.N. Sukachev, biogeocenosis- This a set of homogeneous natural phenomena over a known area of the earth's surface- atmosphere, rock, hydrological conditions, vegetation, fauna, microorganisms and soil. This set is distinguished by the specific interactions of its components, their special structure and a certain type of exchange of substances and energy among themselves and with other natural phenomena.
Biogeocenoses can be of very different sizes. In addition, they are characterized by great complexity - it is sometimes difficult to take into account all the elements, all the links. These are, for example, such natural groups as a forest, lake, meadow, etc. An example of a relatively simple and clear biogeocenosis is a small reservoir or pond. Its non-living components include water, substances dissolved in it (oxygen, carbon dioxide, salts, organic compounds) and soil - the bottom of a reservoir, which also contains a large number of various substances. The living components of a reservoir are divided into primary producers - producers (green plants), consumers - consumers (primary - herbivores, secondary - carnivores, etc.) and destroyers - destructors (microorganisms), which decompose organic compounds to inorganic ones. Any biogeocenosis, regardless of its size and complexity, consists of these main links: producers, consumers, destroyers and components of inanimate nature, as well as many other links. Connections of the most varied orders arise between them - parallel and intersecting, entangled and intertwined, etc.
In general, biogeocenosis represents an internal contradictory dialectical unity, in constant movement and change. “Biogeocenosis is not the sum of biocenosis and environment,” points out N.V. Dylis, “but a holistic and qualitatively isolated phenomenon of nature, acting and developing according to its own laws, the basis of which is the metabolism of its components.”
The living components of biogeocenosis, i.e., balanced animal-plant communities (biocenoses), are the highest form of existence of organisms. They are characterized by a relatively stable composition of fauna and flora and have a typical set of living organisms that retain their basic characteristics in time and space. The stability of biogeocenoses is supported by self-regulation, i.e. all elements of the system exist together, never completely destroying each other, but only limiting the number of individuals of each species to a certain limit. That is why such relationships have historically developed between species of animals, plants and microorganisms that ensure development and maintain their reproduction at a certain level. Overpopulation of one of them may arise for some reason as an outbreak of mass reproduction, and then the existing relationship between the species is temporarily disrupted.
To simplify the study of biocenosis, it can be conditionally divided into separate components: phytocenosis - vegetation, zoocenosis - fauna, microbiocenosis - microorganisms. But such fragmentation leads to an artificial and actually incorrect separation from a single natural complex of groups that cannot exist independently. In no habitat can there be a dynamic system that consists only of plants or only of animals. Biocenosis, phytocenosis and zoocenosis must be considered as biological unities of different types and stages. This view objectively reflects the real situation in modern ecology.
In the conditions of scientific and technological progress, human activity transforms natural biogeocenoses (forests, steppes). They are being replaced by sowing and planting of cultivated plants. This is how special secondary agrobiogeocenoses, or agrocenoses, are formed, the number of which on Earth is constantly increasing. Agrocenoses are not only agricultural fields, but also shelterbelts, pastures, artificially regenerated forests in cleared areas and fires, ponds and reservoirs, canals and drained swamps. Agrobiocenoses in their structure are characterized by a small number of species, but their high abundance. Although there are many specific features in the structure and energy of natural and artificial biocenoses, there are no sharp differences between them. In a natural biogeocenosis, the quantitative ratio of individuals of different species is mutually determined, since mechanisms regulating this ratio operate in it. As a result, a stable state is established in such biogeocenoses, maintaining the most favorable quantitative proportions of its constituent components. In artificial agrocenoses there are no such mechanisms; there, man has completely taken upon himself the responsibility for regulating the relationships between species. Much attention is paid to the study of the structure and dynamics of agrocenoses, since in the foreseeable future there will be practically no primary, natural, biogeocenoses left.
- Trophic structure of biocenosis
The main function of biocenoses - maintaining the cycle of substances in the biosphere - is based on the nutritional relationships of species. It is on this basis that organic substances synthesized by autotrophic organisms undergo multiple chemical transformations and ultimately return to the environment in the form of inorganic waste products, again involved in the cycle. Therefore, with all the diversity of species that make up various communities, each biocenosis necessarily includes representatives of all three fundamental ecological groups of organisms - producers, consumers and decomposers . The completeness of the trophic structure of biocenoses is an axiom of biocenology.
Groups of organisms and their relationships in biocenoses
Based on their participation in the biogenic cycle of substances in biocenoses, three groups of organisms are distinguished:
1) Producers(producers) - autotrophic organisms that create organic substances from inorganic ones. The main producers in all biocenoses are green plants. The activities of producers determine the initial accumulation of organic substances in the biocenosis;
ConsumersIorder.
This trophic level is composed of direct consumers of primary production. In the most typical cases, when the latter is created by photoautotrophs, these are herbivores (phytophagous). The species and ecological forms representing this level are very diverse and are adapted to feeding on different types of plant food. Due to the fact that plants are usually attached to the substrate, and their tissues are often very strong, many phytophages have evolved a gnawing type of mouthparts and various types of adaptations for grinding and grinding food. These are the dental systems of the gnawing and grinding type in various herbivorous mammals, the muscular stomach of birds, especially well expressed in granivores, etc. n. The combination of these structures determines the ability to grind solid food. Gnawing mouthparts are characteristic of many insects and others.
Some animals are adapted to feeding on plant sap or flower nectar. This food is rich in high-calorie, easily digestible substances. The oral apparatus in species that feed in this way is designed in the form of a tube through which liquid food is absorbed.
Adaptations to feeding on plants are also found at the physiological level. They are especially pronounced in animals that feed on the rough tissues of the vegetative parts of plants, containing large amounts of fiber. In the body of most animals, cellulolytic enzymes are not produced, and the breakdown of fiber is carried out by symbiotic bacteria (and some protozoa of the intestinal tract).
Consumers partially use food to support life processes (“respiration costs”), and partially build their own body on its basis, thus carrying out the first, fundamental stage of transformation of organic matter synthesized by producers. The process of creation and accumulation of biomass at the level of consumers is designated as , secondary products.
ConsumersIIorder.
This level unites animals with a carnivorous type of nutrition (zoophagous). Usually, all predators are considered in this group, since their specific features practically do not depend on whether the prey is a phytophage or a carnivore. But strictly speaking, only predators that feed on herbivores and, accordingly, represent the second stage of transformation of organic matter in food chains should be considered second-order consumers. The chemical substances from which the tissues of an animal organism are built are quite homogeneous, therefore the transformation during the transition from one level of consumers to another is not as fundamental as the transformation of plant tissues into animals.
With a more careful approach, the level of consumers of the second order should be divided into sublevels according to the direction of flow of matter and energy. For example, in the trophic chain “cereals - grasshoppers - frogs - snakes - eagles”, frogs, snakes and eagles constitute successive sublevels of consumers of the second order.
Zoophages are characterized by their specific adaptations to their feeding patterns. For example, their mouthparts are often adapted to grasp and hold live prey. When feeding on animals that have dense protective coverings, adaptations are developed to destroy them.
At the physiological level, adaptations of zoophages are expressed primarily in the specificity of the action of enzymes “tuned” to digest food of animal origin.
ConsumersIIIorder.
Trophic connections are most important in biocenoses. Based on these connections of organisms in each biocenosis, so-called food chains are distinguished, which arise as a result of complex food relationships between plant and animal organisms. Food chains unite directly or indirectly a large group of organisms into a single complex, connected to each other by the relationship: food - consumer. The food chain usually consists of several links. The organisms of the subsequent link eat the organisms of the previous link, and thus a chain transfer of energy and matter occurs, which underlies the cycle of substances in nature. With each transfer from link to link, a large part (up to 80 - 90%) of the potential energy is lost, dissipated in the form of heat. For this reason, the number of links (types) in the food chain is limited and usually does not exceed 4-5.
A schematic diagram of the food chain is shown in Fig. 2.
Here, the basis of the food chain is made up of species - producers - autotrophic organisms, mainly green plants that synthesize organic matter (they build their body from water, inorganic salts and carbon dioxide, assimilating the energy of solar radiation), as well as sulfur, hydrogen and other bacteria that use organic substances for the synthesis substances the energy of oxidation of chemicals. The next links in the food chain are occupied by consumer species—heterotrophic organisms that consume organic substances. Primary consumers are herbivorous animals that feed on grass, seeds, fruits, underground parts of plants - roots, tubers, bulbs and even wood (some insects). Secondary consumers include carnivores. Carnivores, in turn, are divided into two groups: those that feed on mass small prey and active predators that often attack prey larger than the predator itself. At the same time, both herbivores and carnivores have a mixed feeding pattern. For example, even with the abundance of mammals and birds, martens and sables also eat fruits, seeds and pine nuts, and herbivores consume some amount of animal food, thus obtaining the essential amino acids of animal origin they need. Starting from the producer level, there are two new ways to use energy. Firstly, it is used by herbivores (phytophages), which directly eat living plant tissue; secondly, they consume saprophages in the form of already dead tissue (for example, during the decomposition of forest litter). Organisms called saprophages, mainly fungi and bacteria, obtain the necessary energy by decomposing dead organic matter. In accordance with this, there are two types of food chains: chains of consumption and chains of decomposition, Fig. 3.
It should be emphasized that food chains of decomposition are no less important than chains of grazing. On land, these chains begin with dead organic matter (leaves, bark, branches), in water - dead algae, fecal matter and other organic debris. Organic residues can be completely consumed by bacteria, fungi and small animals - saprophages; This releases gas and heat.
Each biocenosis usually has several food chains, which in most cases are complexly intertwined.
Quantitative characteristics of biocenosis: biomass, biological productivity.
Biomass And biocenosis productivity
The amount of living matter of all groups of plant and animal organisms is called biomass. The rate of biomass production is characterized by the productivity of the biocenosis. There is a distinction between primary productivity - plant biomass formed per unit time during photosynthesis, and secondary - biomass produced by animals (consumers) consuming primary products. Secondary products are formed as a result of the use of energy stored by autotrophs by heterotrophic organisms.
Productivity is usually expressed in units of mass per year on a dry matter basis per unit area or volume, which varies considerably among different plant communities. For example, 1 hectare of pine forest produces 6.5 tons of biomass per year, and a sugar cane plantation produces 34-78 tons. In general, the primary productivity of the world's forests is the highest compared to other formations. A biocenosis is a historically established complex of organisms and is part of a more general natural complex - an ecosystem.
Ecological pyramid rule.
All species that form the food chain exist on organic matter created by green plants. In this case, there is an important pattern associated with the efficiency of use and conversion of energy in the nutrition process. Its essence is as follows.
Only about 0.1% of the energy received from the Sun is bound through the process of photosynthesis. However, due to this energy, several thousand grams of dry organic matter per 1 m2 per year can be synthesized. More than half of the energy associated with photosynthesis is immediately consumed in the process of respiration of the plants themselves. The other part is transported through food chains by a number of organisms. But when animals eat plants, most of the energy contained in food is spent on various vital processes, turning into heat and dissipating. Only 5 - 20% of food energy passes into the newly built substance of the animal's body. The amount of plant matter that serves as the basis of the food chain is always several times greater than the total mass of herbivorous animals, and the mass of each of the subsequent links in the food chain also decreases. This very important pattern is called rule of the ecological pyramid. An ecological pyramid representing a food chain: cereals - grasshoppers - frogs - snakes - eagle is shown in Fig. 6.
The height of the pyramid corresponds to the length of the food chain.
The transition of biomass from a lower trophic level to a higher one is associated with losses of matter and energy. On average, it is believed that only about 10% of the biomass and its associated energy moves from each level to the next. Because of this, total biomass, production and energy, and often the number of individuals, progressively decrease as they ascend through trophic levels. This pattern was formulated by Ch. Elton (Ch. Elton, 1927) in the form of a rule ecological pyramids
(Fig. 4) and acts as the main limiter on the length of food chains. 
Inhabiting a relatively homogeneous living space (a certain area of land or water area), and connected with each other and their environment. Biocenoses arose on the basis biogenic cycle and provide it in specific natural conditions. Biocenosis is a dynamic system capable of self-regulation, the components of which (producers, consumers, decomposers) are interconnected. One of the main objects of ecology research. The most important quantitative indicators of biocenoses are biodiversity(the total number of species in it) and biomass (the total mass of all types of living organisms in a given biocenosis).
Types of biocenoses: 1) Natural (river, lake, meadow, etc.) 2) Artificial (pond, garden, etc.)
There are 2 types (types) of biocenosis: natural and artificial ( see slide 3). Try to determine what is the difference between these biocenoses. Give examples.
Natural biocenosis – this is the one that nature created. For example, a lake, a forest.
Artificial biocenosis - This is the one that man created. For example, a garden, a vegetable garden.
Natural biocenoses.
The composition of the inhabitants in each of them is not accidental; it depends on the conditions of the given territory and is adapted to them. Biocenoses can be rich in species and poor, for example: in the tundra there is a poor species composition, and in tropical forests it is rich.
The higher the number of species, the more resistant the biocenosis is to various interventions.
The stability of biocenoses is also determined by their tiering - spatial and temporal.
What do you think these concepts mean?
Tiers - floors.
Spatial – located in space (triple dimension).
Temporal – located in time (changes over time)
Spatial layering is characteristic of both animals and plants. Each tier is inhabited by individuals of its own species, but this does not prevent various animals from being in other tiers. However, the main stages of animal life take place in certain tiers. For example, bird nests are located in some tiers, and the search for food can occur in others.
Temporary layering occurs due to feeding habits, construction of nests and houses, and reproduction. For example, the timing of bird arrival depends on the availability of food. In addition, in cases of prolonged cold weather, birds do not begin building nests and laying eggs for a long time.
In natural biocenoses, the species composition is preserved for a long time, and certain relationships are established between different species. There are organisms that are producers, consumers and decomposers. Try to define the concept of “producers”
Producers are those who produce (produce) something.
What organisms do you think could be producers?
Plants, because they produce oxygen and organic matter.
Plants that produce organic substances from inorganic ones are called producers.
If producers are organisms that produce a substance, then who are consumers?
Consumers are those organisms that consume a substance.
Herbivorous animals that create organic substances, but of animal origin, are called consumers of order.
So, we found out who the producers and consumers are. Think and tell me, who are decomposers and what role should they play?
Decomposers are organisms that process the remains of dead animals and plants.
Decomposers are organisms that feed on the remains of dead plants and animals. These include bacteria, fungi and some animals, such as worms.
In a natural biocenosis, self-regulation of the number of individuals of each group occurs.
What features do you think the artificial biocenosis will have?
Only what man has planted will grow there, and only a few species of animals will live.
Artificial biocenoses
Agriculture led to the destruction of natural and creation of artificial biocenoses (agrobiocenoses). Growing large areas of plants of the same species, for example, potatoes, wheat, led to a sharp reduction in connections between species. The agrobiocenosis is characterized by insignificant stability, because there is no tiering (both temporal and spatial).
Cultivated plants form a specific composition of the inhabitants of the animal world with a predominance of herbivorous species, mainly insect pests. All individuals are characterized by good adaptability to rapid changes in vegetation cover and omnivory.
To combat them, people use various methods, use pesticides, polluting the environment, destroying both harmful and beneficial animals. To maintain the sustainability of artificial biocenoses, large financial costs are required.
For example, consider the biocenosis of a reservoir .
Producers here are all types of plants, which in most cases are located in the upper layers. Microscopic algae form phytoplankton.
First order consumers are microscopic animals that form zooplankton, which feed on phytoplankton and directly depend on its development.
Second order consumers are fish that feed on crustaceans and insects.
Second order consumers are predatory fish.
Consumers can live at various depths, including at the bottom.
The remains of the vital activity of all organisms sink to the bottom and become food for decomposers, which decompose them into inorganic substances.
Goals and objectives of the lesson:
Formation of knowledge among students:
- about biocenosis as a sustainable system;
- about natural and artificial biocenoses;
- about the obligatory components of the biocenosis:
- producers;
- consumers;
- decomposers.
- Introducing students to the reasons for the stability of natural biocenosis and the instability of artificial ones.
Lesson type. Discussion lecture using presentation.
Equipment. Computers, projector, CD "Biology", electronic tests.
During the classes:
I. Updating knowledge.
Individual survey:
1. What is the evidence that natural selection is the leading cause of animal evolution?
2. Why is the emergence of habitats in nature and their types the result of the adaptation of animals?
3. What are the patterns of distribution of animals in nature?
II. Learning new material.
Children, looking at the topic of the lesson, formulate the goals and objectives of the lesson.
! (suggested answer):
- find out what biocenosis is;
- What does artificial and natural biocenosis mean?
Word to the teacher:
We are all concerned about a serious question:
What is biocenosis?
I will solve this problem, friends, -
This is such a big family:
Animals and birds, beetles, spiders,
Forest, there are birches, aspens, oaks,
Worms and mice, air, earth,
Fallen leaves, maybe pine needles,
Even the path where you carried mushrooms,
This is what biocenosis is.
What do you think, based on the poem you read, what definition can be given to the concept of “biocenosis”?
Biocenosis is a community (totality) of plants, animals and other organisms.
There are 2 types (types) of biocenosis: natural and artificial (see slide 3). Try to determine what is the difference between these biocenoses. Give examples.
A natural biocenosis is one that nature created. For example, a lake, a forest.
An artificial biocenosis is one created by man. For example, a garden, a vegetable garden.
Natural biocenoses.
The composition of the inhabitants in each of them is not accidental; it depends on the conditions of the given territory and is adapted to them. Biocenoses can be rich in species and poor, for example: in the tundra there is a poor species composition, and in tropical forests it is rich (see slides 4-7)
The higher the number of species, the more resistant the biocenosis is to various interventions.
The stability of biocenoses is also determined by their tiering - spatial and temporal (see slide 8).
What do you think these concepts mean?
Tiers - floors.
Spatial – located in space (triple dimension).
Temporal – located in time (changes over time)
Spatial layering (see slide 9) is characteristic of both animals and plants. Each tier is inhabited by individuals of its own species, but this does not prevent various animals from being in other tiers. However, the main stages of animal life take place in certain tiers. For example, bird nests are located in some tiers, and the search for food can occur in others.
If producers are organisms that produce a substance, then who are consumers?
! Consumers are those organisms that consume a substance.
Herbivorous animals that create organic substances, but of animal origin, are called consumers of the first order (see slide 13).
So, we found out who the producers and consumers are. Think and tell me, who are decomposers and what role should they play?
! Decomposers are organisms that process the remains of dead animals and plants.
Decomposers are organisms that feed on the remains of dead plants and animals (see slide 14). These include bacteria, fungi and some animals, such as worms.
In a natural biocenosis, self-regulation of the number of individuals of each group occurs.
What features do you think the artificial biocenosis will have?
! Only what man has planted will grow there, and only a few species of animals will live.
Agriculture led to the destruction of natural and creation of artificial biocenoses (agrobiocenoses). Growing large areas of plants of the same species, for example, potatoes, wheat, led to a sharp reduction in connections between species. The agrobiocenosis is characterized by insignificant stability, because there is no tiering (both temporal and spatial).
Cultivated plants form a specific composition of the inhabitants of the animal world with a predominance of herbivorous species, mainly insect pests. All individuals are characterized by good adaptability to rapid changes in vegetation cover and omnivory.
To combat them, people use various methods, use pesticides, polluting the environment, destroying both harmful and beneficial animals. To maintain the sustainability of artificial biocenoses, large financial costs are required.
For example, consider the biocenosis of a reservoir (see slide 16) .
Producers here are all types of plants, which in most cases are located in the upper layers. Microscopic algae form phytoplankton.
First order consumers are microscopic animals that form zooplankton, which feed on phytoplankton and directly depend on its development.
Second order consumers are fish that feed on crustaceans and insects.
Second order consumers are predatory fish.
Consumers can live at various depths, including at the bottom.
The remains of the vital activity of all organisms sink to the bottom and become food for decomposers, which decompose them into inorganic substances.
III. Physical exercise.
One two three four.
Biofamilies were studied
Learned a lot of new things
And a little tired.
We turn our eyes
Let's shake our heads.
Hands, legs pulled,
Take a good breath,
They leaned over once and twice.
Are you feeling dizzy?
Well, if everything is okay with you,
Let's work in a notebook.
IV. Consolidation of new material.
1. Work in a notebook (consolidating the concepts of “biocenosis”, “natural biocenosis”, “artificial biocenosis”).
RT. Page 132, no. 1, no. 2.
2. Independent work (working on concepts).
Strong students consider the biocenosis of a reservoir (work on sheets - templates).
Weak students watch the film “Ants” and answer questions (work on sheets - templates).
A certain time is given for work. After time has passed, students answer the questions posed (comment on the display of their material).
3. This is interesting.
Sheets (with different information) are distributed to students. After 2–3 minutes, you are asked to read out your 2 favorite facts.
Performing test tasks in the “Knowing” program. Students open the “Knowing” folder on the Desktop, select the “Biocenosis” test and begin testing.
IV. Lesson summary. Reflection. D/z.
1.So, today we have done a lot of work. Let's summarize. What new did you learn today and where can it be useful to you in life?
Answer options are listened to.
2. Homework:
So we answered the question -
“What is a biocenosis?”
Here everyone lives as a family,
They breathe, eat, even grow.
Everyone got used to it, order is everywhere,
Everything is according to the law “You - for me, I - for you”
If suddenly something bad happens to someone -
There is no need to cry, such is fate.
In general, everyone has their own share,
There is me somewhere in this system.
Now, I hope, the question will not arise
“What is a biocenosis?”
Agrocenosis is an artificial biogeocenosis that appeared as a result of human agricultural activity. Examples: garden, pasture, field. The similarity of agrocenosis and biogeocenosis is expressed in the fact that both have producers, consumers and destroyers of organic matter, which ensure the circulation of substances and the flow of energy. The inhabitants of the agrocenosis are also connected by food chains, the initial link of which is plants. However, there are differences between the natural community and agrocenosis. An agrocenosis is composed of a small number of species; as a rule, organisms of one species predominate in it (for example, wheat in a field, sheep in a pasture). The food chains of the agrocenosis are short. The cycle of substances is incomplete; a significant part of the biomass in the form of crops is carried outside the agrocenosis. Weakly expressed self-regulation in agrocenosis makes it unstable.
In artificial biocenoses, components are selected based on economic value. Here the leading role is played by artificial selection, through which a person strives to obtain maximum productivity (harvest). The source of energy in agrocenosis, as well as in biogeocenosis, is solar energy, but high productivity is ensured largely through the application of fertilizers.
High productivity of cultivated plants is also achieved by taking into account their biological needs (nutrients, heat, moisture, protection from pests). An important condition for obtaining high yields is the timely implementation of agricultural work. In general, agrocenoses provide high biological productivity due to continuous human intervention and support; without his participation they cannot exist.
Technocenosis is an artificial system limited in time and space, a community of products with weak connections and common goals, allocated for the purposes of design or construction.
The analysis of technocenoses is similar to the methods of biological research; within the framework of a technocenosis (for example, an industrial enterprise), families of products, as well as their individual types, are distinguished. Each specific product, on the one hand, is unique, and on the other hand, it is created on the basis of drawings or other information that can be identified with the genetic code of living beings.
Technocenoses can be divided into a separate group in relation to living and inanimate matter.
The current technocenosis has stability of both development and structure. New technocenoses are born within the framework of existing ones; their independent development occurs as a result of a significant spread of the engineering and scientific solutions underlying them, leading to the emergence of new sectors of the economy. The replacement of some technocenoses by others is a process of development of productive forces and the evolutionary development of technocenoses within the technosphere.
Urbanocenosis - urban ecosystem; a depleted complex consisting of synanthropes, ruderal, sagetal and cultivated plants, some types of microorganisms, well adapted to the urban environment and to each other. Man is part of the urban cenosis complex.
As an ecological system, the urban community has a very complex structure. It can be divided into a built-up part (houses, roads, communications, etc.) and undeveloped areas in which the remains of more or less modified natural communities have been preserved or artificial plantings have been created. The suitability of such undeveloped areas for the life of various animals and plants is determined by the size of the territory, its surroundings, the degree of anthropogenic load, the duration of existence within the city, isolation from other habitats, etc.
