Description: War Thunder is a next generation military MMO game dedicated to...
abstract
discipline: "Concepts modern natural science».
Presentation on theme: "Diversity of living organisms
the basis of the organization and stability of the biosphere”.
Introduction
1. The basis of the organization and stability of the biosphere
2. Distribution of living matter
3. Classification of living matter
4. Migration and distribution of living matter
5. The constancy of the biomass of living matter
6. Functions of living matter in the biosphere of the Earth
Conclusion
Bibliography
Introduction
The huge species diversity of living organisms provides a constant mode of biotic circulation. Each of the organisms enters into specific relationships with the environment and plays its role in the transformation of energy. This formed certain natural complexes, which have their own specifics depending on environmental conditions in one or another part of the biosphere. Living organisms inhabit the biosphere and are included in one or another biocenosis - spatially limited parts of the biosphere - not in any combination, but form certain communities of species adapted to cohabitation. Such communities are called biocenoses.
An important ecological rule is that the more heterogeneous and complex the biocenoses, the higher the stability, the ability to withstand various external influences. Biocenoses are distinguished by great independence. Some of them persist for a long time, others naturally change. Lakes turn into swamps - peat is being formed, and as a result, a forest grows on the site of the lake.
The process of regular changes in the biocenosis is called succession. Succession is a successive change of some communities of organisms (biocenoses) by others in a certain area of the environment. In a natural course, succession ends with the formation of a stable community stage. In the course of succession, the diversity of the species of organisms that make up the biocenosis increases, as a result of which its stability increases.
The increase in species diversity is due to the fact that each new component of the biocenosis opens up new opportunities for invasion. For example, the appearance of trees allows species living in the subsystem to penetrate into the ecosystem: on the bark, under the bark, building nests on branches, in hollows.
In the course of natural selection, only those types of organisms that can most successfully reproduce precisely in this community. The formation of biocenoses has an essential side: "competition for a place under the sun" between different biocenoses. In this “competition”, only those biocenoses are preserved that are characterized by the most complete division of labor between their members, and, consequently, richer internal biotic connections.
Since each biocenosis includes all the main environmental groups organisms, it is equal in its capabilities to the biosphere. The biotic cycle within the biocenosis is a kind of reduced model of the Earth's biotic cycle.
1. The basis of the organization and stability of the biosphere
The term "biosphere" was introduced to refer to the general appearance of the Earth's surface, due to the presence of the entire mass of living organisms on it. The two main components of the biosphere are living organisms and their habitat (including the lower atmosphere, aquatic environment) - coexist in constant interaction, forming an integral system. Separate populations of living organisms are not isolated from the environment. In the course of evolution, biocenoses are formed - communities of animals, plants, microorganisms. Together with the habitat, biocenoses form biogeocenoses. They have a continuous exchange of matter and energy, which are realized by many trophic chains and biogeochemical cycles. Biogeocenoses serve as elementary cells of the biosphere, which, interacting with each other, establish a dynamic balance in it. Living matter plays a system-forming role in the supersystem of life - the biosphere. High degree the consistency of all types of life in the biosphere is the result of the joint evolution of interacting biological systems - co-evolution. Co-evolutionary development is manifested in the subtle mutual adaptability of species, in the complementarity of living systems. Ultimately, coevolution leads to an increase in diversity and complexity in nature. This representation is the essence of the concept of co-evolution. According to it, the diversity of living organisms is the basis for the organization and stability of the biosphere. Each species performs its function in the biospheric circulation of matter, energy, in the exchange of information and the implementation of feedback. In this regard, the danger of a decrease in the number of species of living organisms and a reduction in the gene pool, which continuously occur under pressure, is obvious. human civilization on nature.
In this way
1. The stability of the biosphere as a whole, its ability to evolve is determined by the fact that it is a system of relatively independent biocenoses. The relationship between them is limited to connections through non-living components of the biosphere: gases, atmosphere, mineral salts, water, etc.
2. The biosphere is a hierarchically built unity, including the following levels of life: individual, population, biocenosis, biogeocenosis. Each of these levels has a relative independence, and only this ensures the possibility of the evolution of the entire large macrosystem.
3. The diversity of life forms, the relative stability of the biosphere as a habitat and life certain types create the prerequisites for the morphological process, important element which is the improvement of behavioral reactions associated with progressive development nervous system. Only those types of organisms survived that, in the course of the struggle for existence, began to leave offspring, despite the internal restructuring of the biosphere and the variability of cosmic and geological factors.
2. Distribution of living matter
“To be alive,” noted V.I. Vernadsky means to be organized. Throughout the billions of years of existence of the biosphere, organization is created and maintained through the activity of living organisms.
Live nature is the main feature of the manifestation of the biosphere, it sharply distinguishes it from other earthly shells. The structure of the biosphere is primarily and most of all characterized by life. This most powerful geological force, living matter planets, is a collection of very fragile and delicate living organisms, by weight constituting an insignificant part of the biosphere they created.
If living matter is evenly distributed over the surface of our planet, then it will cover it with a layer of only 2 cm thick.
Chemical composition elements of the living matter of our planet is characterized by the predominance of a few elements: hydrogen, carbon, oxygen, nitrogen are the main elements of terrestrial living matter and therefore are called biophilic. Their atoms create complex molecules in living organisms in combination with water and mineral salts.
The living substances of our planet exist in the form of a huge variety of organisms with their own individual characteristics, various shapes and sizes. Among living organisms there are the smallest microorganisms and multicellular animals and plants. large sizes. Sizes range from micrometers (small bacteria, ciliates) to tens of meters.
The population of the biosphere in terms of species and morphology is also extremely diverse. Calculations of the number of species inhabiting our planet were carried out by various authors, but they can still be considered only approximate.
According to modern estimates, there are about 3 million species of organisms on Earth, of which plants account for 500,000 species, and animals account for 2.5 million species. Since the time of Aristotle, the entire organic world of our planet has traditionally been divided into plants and animals. At present, thanks to the study of the structure of the organization of living beings, it is possible to carry out a more perfect classification than it was before.
Living matter, according to V.I. Vernadsky, "spreads over the earth's surface and exerts a certain pressure on the environment, bypasses obstacles that impede its progress, or takes possession of them, covers them." The internal energy produced by life is manifested in the transfer of chemical elements and in the creation of new bodies from them. According to V.I. Vernadsky, the geochemical energy of life is expressed in the movement of living organisms through reproduction, which goes on continuously in the biosphere. The reproduction of organisms produces the "pressure of life" or "pressure of life." In this connection, a struggle arises between organisms for space, nutrition, and especially “for gas”, free oxygen necessary for breathing.
In this case, a biogenic migration of atoms occurs: atoms captured by plants pass to herbivores, then to predators that feed on herbivores. Dead plants and animals serve as food for microorganisms, and the minerals released by microorganisms as a result of vital activity are again consumed by plants. Only a small percentage of atoms fall out of this biological cycle. These biogenic atoms released from the life process end up in inert (non-living) nature, thereby playing a huge role in the history of the biosphere.
The reproduction process stops only when there is a lack of oxygen in the environment, the action low temperatures and lack of habitat for new organisms.
IN AND. Vernadsky calculated the time required various organisms to "capture" the surface of the planet.
Thus, he concluded that small organisms reproduce faster than large ones, and domestic animals reproduce faster than wild ones.
3. Classification of living matter
The whole world of living beings is currently divided into two large systematic groups: prokaryotes and eukaryotes.
Prokaryotes (from Latin pro - forward, instead of Greek kaguop - nucleus) - organisms that, unlike eukaryotes, do not have a well-formed cell nucleus and a typical chromosome apparatus. Their hereditary information is realized and transmitted through DNA, there is no typical sexual process. These include bacteria, such as blue-green algae. In the system of the organic world, prokaryotes constitute an over-kingdom.
Eukaryotes (from Greek eu - good, completely and karyon - core) - organisms that, unlike prokaryotes, have a formed cell nucleus, separated from the cytoplasm by a nuclear membrane. genetic material they have chromosomes, the sexual process is characteristic. They include everything except bacteria.
The most low-organized living organisms are those that do not have a true cell nucleus, DNA is located freely in the cell, not separated from the cytoplasm by the nuclear membrane. These organisms are called prokaryotes. All other organisms are called eukaryotes.
It is the prokaryotes that our planet owes the appearance of the atmosphere. Prokaryotes could exist in completely unthinkable conditions that developed on our planet 3 billion years ago - intense ultraviolet radiation not retained by the ozone layer, the most active volcanism - and were one of the most adapted living creatures. Their descendants, for example, blue-green algae, still have extraordinary vitality.
PAGE_BREAK--
A huge step in the evolution of living matter was made when eukaryotes appeared with their oxygen respiration. The transition from prokaryotes to eukaryotes, which caused a grandiose restructuring of the biosphere, took another billion years. Prokaryotes paid for the acquisition of oxygen starvation by becoming mortal in the usual sense of the word, in contrast to eukaryotes, which, apparently, did not have a natural death. But along with this, they also acquired a much greater efficiency of energy use than that of prokaryotes, thanks to which they were able to evolve much faster and became capable of self-improvement.
4. Migration and distribution of living matter
In connection with the action of solar energy and the internal energy of the Earth, constant processes of movement and redistribution of matter take place in the biosphere. It carries out mass transfer of solid, liquid and gaseous bodies at various temperatures and pressures. On Earth, 1012 tons of living matter will be destroyed annually from general stock 1013 tons. Such an intensive circulation of substances, which created the biosphere and determines its stability and integrity, is associated with the vital activity of the planet's biomass. Unlike dead matter, living matter is capable of accumulating energy, multiplying, and has a tremendous reaction rate. On Earth there is no force more constantly acting, and therefore more powerful in its consequences, than living organisms taken together. Life on Earth is impossible without the circulation of substances. Accumulation and mineralization occurs in biocenoses. The main carbon cycle consists in the conversion of CO2 into living matter, from which, when decomposed by bacteria and respiration, CO2 is re-formed.
The nitrogen cycle is associated with the conversion of atmospheric molecular nitrogen into nitrates due to the activity of certain bacteria and the energy of lightning discharges. Nitrates are absorbed by plants. As part of their proteins, nitrogen gets to animals, and after the death of plants and animals - to the soil, where putrefactive bacteria decompose organic residues to ammonia, which is then oxidized by bacteria into nitric acid. Thus, the accumulation of chemical elements in living organisms and their release as a result of the decomposition of the dead - salient feature biogenic migration.
The renewal of biomass on land occurs on average in 15 years, and for forest vegetation this value is much larger, and for herbaceous vegetation it is much less. In the ocean, the total mass of living matter is renewed on average every 25 days. Renewal of the entire biomass of the Earth is carried out in 7-8 years.
5. The constancy of the biomass of living matter
The amount of biomass of living matter tends to a certain constancy. This is achieved by the fact that in nature there is an opposite direction of processes.
The most important link in the biochemical cycle is photosynthesis - a powerful natural process that annually involves huge masses of biosphere matter in the cycle and determines its high oxygen potential. This process acts as a regulator of the main geochemical processes in the biosphere and as a factor determining the presence of free energy of the upper shells. the globe. Due to carbon dioxide and water, organic matter is synthesized and free oxygen is released. Photosynthesis occurs on the entire surface of the Earth and creates a huge geochemical factor, which can be expressed by the amount of carbon mass annually involved in the construction of organic living matter of the entire biosphere. The productivity of planetary photosynthesis can be expressed in the amount of masses of carbon dioxide and water consumed by all plants of the globe during the year. Given that the waters of the oceans have gone through the biogenic cycle associated with photosynthesis at least 300 times, the free oxygen of the atmosphere has been renewed at least one million times.
When the organism dies, the reverse process occurs - the decomposition of organic matter by oxidation, decay, etc. with the formation of decomposition products.
The intensity of life is expressed in the growth and reproduction of organisms. For all the time of the development of the biosphere, the energy of the Sun turned into the biochemical energy of the reproduction of living organisms. In this case, the absorbed energy was divided into two components: the growth component, leading to a certain mass of a given body, and the reproduction component, which determines an increase in the number of organisms of a given species.
6. Functions of living matter in the biosphere of the Earth
The functions of living matter in the Earth's atmosphere are quite diverse. IN AND. Vernadsky singled out five such functions:
1. gas function. It is carried out by green plants. Plants use carbon dioxide to synthesize organic substances, while releasing oxygen into the atmosphere. The rest of the organic world uses oxygen in the process of respiration and replenishes the carbon dioxide reserves in the atmosphere. As the biomass of green plants increases, the gas composition of the atmosphere changes: the content of carbon dioxide decreases and the concentration of oxygen increases. Thus, living matter has qualitatively changed the composition of the atmosphere - the geological shell of the Earth.
2. The redox function is closely related to the gas function. In the course of their life activity and after their death, organisms living in different water bodies regulate the oxygen regime and thereby create conditions favorable for the dissolution of a number of metals, which leads to the formation of sedimentary rocks.
3. The concentration function is manifested in the ability of living organisms to accumulate various chemical elements, for example, storage plants such as sedge and horsetail contain a lot of silicon. Thanks to the implementation of the concentration function, living organisms have created many sedimentary rocks: deposits of chalk, limestone, etc.
4. The biochemical function is associated with the growth, reproduction and movement of living organisms in space. Reproduction leads to the rapid spread of living organisms and the spread of living matter to different geographical areas.
5. Biochemical activity covers an ever-increasing amount of matter earth's crust for the needs of industry, transport, Agriculture and human needs.
Conclusion
“To be alive,” wrote V.I. Vernadsky means to be organized. Throughout the billions of years of existence of the biosphere, organization is created and maintained through the activity of living organisms.
Bibliography
1. Diaghilev F.M. Concepts of modern natural science. - M.: Ed. IEMPE, 2008.
2. Nedelsky N.F., Oleinikov B.I., Tulinov V.F. Concepts of modern natural science. - M: Ed. Thought, 2006.
3. Grushevitskaya T.G., Sadokhin A.P. Concepts of modern natural science.- M.: Ed. UNITY, 2005.
3. Karpenkov S.Kh. Basic concepts of natural science. – M.: Ed. UNITY, 2004.
Organizing time. T.B. briefing
Introductory conversation about the tasks of the excursion and the rules of conduct during it. Distribution of students into groups.
Variety of plants (trees, shrubs and herbs)
Identification of autumn phenomena in plant life.
The story of the teacher on the topic of the excursion during the bypass of the territory of the school yard.
Independent work of students on assignments for the excursion.
The class is divided into 5 groups. Each group receives a card with a task. At the end of the tour, each group provides an oral report on the work done. Each student provides a complete written report on the excursion in the form homework to the next lesson.
Group #1
1. Take a close look at the plants in the school yard. How many cultural zones with a predominance of certain vegetation can be distinguished? Give your names to these areas.
Count the number of birches in the school yard.
Find out which autumn phenomena can be observed in the life of a birch. Collect 5 birch leaves of different colors.
D/Z.
2. Write a short message about the birch.
3. Dry the leaves collected during the tour and glue them to the report.
Card - tasks for excursion No. 1
Group number 2.
Take a close look at the plants in the school yard. Count how many trees and how many shrubs are on its territory.
Find a bush with fruits in the school yard. Find out the name of this shrub.
Gather some leaves and fruits from this shrub.
D/Z.
1. On an A4 sheet, answer in writing the tasks of the excursion card.
2. Write a short note about any shrub that grows in the school yard.
3. Dry the leaves and fruits collected during the excursion and attach them to the report.
Card - tasks for excursion No. 1
Group number 3.
Take a close look at the plants growing in the school flower bed number 1. Give a name to this flower bed. Find out the name of flowering plants.
Collect carefully a few flowers and fruits (seeds) of plants.
D/Z.
1. On an A4 sheet, answer in writing the tasks of the excursion card.
2. Sketch a few plants in flower bed No. 1 and sign the names of these plants.
3. Dry the flowers collected on the excursion, attach the flowers and fruits (seeds) to the report.
Card - tasks for excursion No. 1
Group number 4.
Take a close look at the plants growing in the school flower bed number 2. Give a name to this flower bed. Find out the name of flowering plants.
Count how many flowers grow in this flower bed.
Collect carefully several types of fruits (seeds) of plants in this flower bed.
D/Z.
1. On an A4 sheet, answer in writing the tasks of the excursion card.
2. Draw a few plants in flower bed No. 2 and sign the names of these plants.
3. Dry the leaves collected during the tour. Attach fruits (seeds) and leaves to the report.
Card - tasks for excursion No. 1
Group number 5.
1. Find out what trees grow in the school yard..
Count how many pine trees grow in the school yard.
Gather some pine leaves and fruits.
D/Z .
1. On a sheet of format A 4, answer in writing the tasks of the excursion card.
2. Write a short message about a pine tree.
3. Dry the pine leaves and attach them to the report. Draw a pine cone.
4. Results of the excursion. Oral report of each group.
Explanation D/Z
This excursion can be carried out while studying the topic "Evolutionary Teaching". It greatly enhances students' interest in learning material topics, facilitates its assimilation, promotes students' understanding of the main provisions of the evolutionary doctrine.
Download:
Preview:
Excursion on the topic: "The reasons for the diversity of species in nature."
In the course of general biology, evolutionary doctrine occupies a special place. In the KIM of the unified state exam in biology, there are many questions on the evolutionary teachings of Charles Darwin. The task of the teacher is to build the educational process in such a way as to ensure that the students learn this teaching firmly. I believe that an excursion into nature to study the causes of species diversity plays a big role in the assimilation of evolutionary knowledge, where students get acquainted with biological phenomena, establish patterns, and master the ability to obtain knowledge through observations in nature.
I am taking this excursion to Kumysnaya Polyana. This is the most picturesque place in our city. Together with the students we get great pleasure from communication with nature.
Tour objectives:
1. introduce the concept of species diversity as a result of natural selection.
2. introduce the concepts of "species criteria", "population", "variability", "heredity".
3. identify different relationships between individuals of the same species, different species.
4. show on concrete examples the adaptability of organisms to endure adverse conditions in autumn and winter.
5. to teach to work collectively, to form a feeling careful attitude to nature, a sense of beauty, the ability to see the beauty of nature.
6. develop interest in biology, the ability to observe, compare, establish cause-and-effect relationships, highlight the main thing, draw conclusions.
Tour plan:
- Organizing time.
- Conversation, frontal observation.
- Group assignments.
- Summarizing. Final conversation.
The course of the tour.
Tasks for groups, the composition of groups is determined in the class, at the previous lesson. At the beginning of the tour, I check the composition of the groups, conduct a briefing on the behavior on the tour. Then we set off through 5-Dachnaya past the spring to Kumysnaya Polyana. During the movement, students name the types of trees of the first tier, second tier, herbaceous plants, types of shrubs. I draw attention to the fact that students give the correct (double) specific names. I draw the attention of students that in a small area of \u200b\u200bthe forest, plants grow different types. I formulate the main question: "What are the reasons for the diversity of species?". This is the main question of our excursion. Then I suggest that students find out how species, for example, of the same genus, (American maple, Tatar maple) differ from each other. To reveal the concept of "species", we use plants of similar species, this works well on plants such as caustic buttercup, creeping, Kashubian. The same examples are used in this textbook. We compare the conditions of their growth and note that the features of the existence of the species constitute an ecological criterion. Let's study them further appearance. We define similar features and their differences in the structure of the flower, leaves. We draw conclusions. I inform students that structural features constitute the morphological criterion of the species. During the conversation, we find out that these plants have different dates flowering. We see the flowering of buttercup caustic. Buttercup Kashubian blooms at the end of May, and creeping buttercup - in July. (we know this from previous excursions). We conclude that different types of asthenia differ in terms of flowering, growth and development rates. We note that the characteristics of the response of organisms of the same species to changes in living conditions constitute the physiological criterion of the species. Conclusion: all species differ from each other in morphological, ecological, physiological features.
We move on. We went out to a clearing, where there is a lot of caustic buttercup. Did you meet caustic buttercup in the forest? No. Where else have we seen this plant? We remember that when we entered the forest, in that clearing we saw this plant. Does buttercup pollen get from one clearing to another? Silence. During the conversation, we find out that this is unlikely, because the clearings are located far from each other. So these plants live apart from each other. We introduce the concept of "population". A group of individuals of the same species that exists for a long time in a certain area apart from other such groups is called a population. Warty birch, Tatar maple, pedunculate oak, growing in our forest, also represent populations of species. A population is a form of existence of a species. A population is stable if it contains individuals of different ages. Task: find individuals of different ages in the Tatar maple population. Students do it with great pleasure. Next, I propose to consider 2-3 individuals of the warty birch. Look for similarities. There are many common signs. What is the reason for their similarity? They are closely related, because. belong to the same population. The set of basic traits is transmitted from parents to offspring. It is common for all living organisms to preserve and transmit their characteristics and properties to offspring. This property is heredity. It is this property that determines the similarity of closely related organisms. Then I propose to find differences among these individuals. Conclusion: all individuals, even in the same population, differ from each other, which means that organisms are characterized by variability. I explain that variability manifests itself in varying degrees of development of certain traits, for example, color intensity, body size, etc. The change in these signs occurs under the influence of conditions environment. We draw attention to the differences in the color of the leaves of common goutweed, growing in open areas and in the forest. The second leaves are darker, they form more chlorophyll. Due to this feature, in plants in the forest under low illumination, the synthesis of organic substances occurs quite intensively. But these changes are not inherited. This is an example of non-hereditary variability. Only such changes in traits are inherited, the development of which is caused by changes in the hereditary material. It is hereditary variability that causes the emergence of new traits, which are the material for natural selection and a prerequisite for the formation of new species. Next, we pay attention to the huge variety of living organisms that inhabit the forest. Students try to establish what relationships exist between them. The totality of all relationships Ch. Darwin called the struggle for existence. During the tour we find herbaceous plants and count the number of seeds (fruits) on it. Will all these seeds grow into mature plants? Of course not. Why? If all the seeds crumble in this place and germinate, then in the dense seedlings between the seedlings there will be an acute struggle for existence - for moisture, nutrients, light. Ch.Darwin called such struggle intraspecific. Then we pay attention to some oppressed plants of poplar, warty birch, Tatar maple. Why are they like this? Ch. Darwin argued that complicated relationship established between organisms of different species. This is an interspecies struggle for existence. Plants also struggle with adverse environmental conditions. Many organisms die from severe frosts, fires, heavy rain, and a person is sometimes guilty. In the struggle for existence in a population of plants (animals) occurs natural selection: some individuals die, while others survive, give viable offspring, are characterized by high adaptability to new environmental conditions. I suggest that students establish signs of adaptability of plants and animals to living conditions. The guys are working. Next, we study what adaptations plants have for the transfer of adverse conditions in autumn-winter period. I pay attention to beauty autumn forest. The students then work in groups to complete the tasks.
Tasks:
1. Draw up a plan of the site and characterize its relief, humidity, illumination, type of soil.
2. Determine the main types of trees, shrubs, grasses and identify their adaptability to cohabitation and to factors inanimate nature. Record the results in a table.
Types of trees. | Types of shrubs. | Types of herbs. | Features of adaptation to cohabitation. | Features of adaptability to abiotic factors. |
3. define the criteria for one type of tree (shrubs or grasses). Enter the data into a table.
Species name:
Physiological signs
environmental signs.
4. Compare 2-3 individuals of the same plant species growing in the same place. Signs of similarity, signs of difference.
5. Compare 2-3 individuals of the same plant species growing in different conditions.
6. What impact on nature have you observed in the forest? The tasks for the students are the same, but each group works in its own area.
Such excursions are very informative and exciting. During the tour we notice broken branches of trees, carved inscriptions on the bark of trees. We make sure to explain what the consequences of these actions may be, how they affect nature. We talk about the careful attitude of man to nature.
Excursion No. 1 . Variety of species in native nature.Seasonal changes (rhythms) in wildlife.
Tour objectives:
1. introduce the concept of species diversity as a result of natural selection.
2. introduce the concepts of "species criteria", "population", "variability", "heredity".
3. identify different relationships between individuals of the same species, different species.
4. show on specific examples the adaptability of organisms to endure adverse conditions in autumn.
5. to teach to work collectively, to form a sense of respect for nature, a sense of beauty, the ability to see the beauty of nature.
6. develop interest in biology, the ability to observe, compare, establish cause-and-effect relationships, highlight the main thing, draw conclusions.
Tour plan:
Organizing time.
Conversation, frontal observation.
Group assignments.
Summarizing. Final conversation.
The course of the tour.
Tasks for groups, the composition of groups is determined in the class, at the previous lesson. At the beginning of the tour, I check the composition of the groups, conduct a briefing on the behavior on the tour. During the movement, students name the types of trees of the first tier, the second tier, herbaceous plants, types of shrubs. I draw attention to the fact that students give the correct (double) specific names. I draw the attention of students that in a small area of \u200b\u200bthe forest, plants of different species grow. I formulate the main question: "What are the reasons for the diversity of species?". This is the main question of our excursion. Then I suggest that students find out how species, for example, of the same genus, (American maple, Tatar maple) differ from each other. To reveal the concept of "species", we use plants of similar species, this works well on plants such as caustic buttercup, creeping, Kashubian. We compare the conditions of their growth and note that the features of the existence of the species constitute an ecological criterion. Next, we study their appearance. We determine similar features and their differences in the structure of the flower, leaves. We draw conclusions. I inform students that structural features constitute the morphological criterion of the species. During the conversation, we find out that these plants have different flowering periods. We see the flowering of buttercup caustic. Buttercup Kashubian blooms at the end of May, and creeping buttercup - in July. . We conclude that plants of different species differ in flowering time, growth rate and development. We note that the characteristics of the response of organisms of the same species to changes in living conditions constitute the physiological criterion of the species. Conclusion: all species differ from each other in morphological, ecological, physiological features.
We move on. We went out to a clearing, where there is a lot of caustic buttercup. Did you meet caustic buttercup in the forest? No. Where else have we seen this plant? We remember that when we entered the forest, in that clearing we saw this plant. Does buttercup pollen get from one clearing to another? Silence. During the conversation, we find out that this is unlikely, because the clearings are located far from each other. So these plants live apart from each other. We introduce the concept"population". A group of individuals of the same species that exists for a long time in a certain area apart from other such groups is called a population. Warty birch, Tatar maple, pedunculate oak, growing in our forest, also represent populations of species. A population is a form of existence of a species. A population is stable if it contains individuals of different ages. Task: find individuals of different ages in the Tatar maple population. Students do it with great pleasure. Next, I propose to consider 2-3 individuals of the warty birch. Look for similarities. There are many common signs. What is the reason for their similarity? They are closely related, because. belong to the same population. The set of basic traits is transmitted from parents to offspring. It is common for all living organisms to preserve and transmit their characteristics and properties to offspring. This property is heredity. It is this property that determines the similarity of closely related organisms. Then I propose to find differences among these individuals. Conclusion: all individuals, even in the same population, differ from each other, which means that organisms are characterized by variability. I explain that variability manifests itself in varying degrees of development of certain traits, for example, color intensity, body size, etc. The change in these signs occurs under the influence of environmental conditions. We draw attention to the differences in the color of the leaves of common goutweed, growing in open areas and in the forest. The second leaves are darker, they form more chlorophyll. Due to this feature, in plants in the forest under low illumination, the synthesis of organic substances occurs quite intensively. But these changes are not inherited. This is an example of non-hereditary variability. Only such changes in traits are inherited, the development of which is caused by changes in the hereditary material. It is hereditary variability that causes the emergence of new traits, which are the material for natural selection and a prerequisite for the formation of new species. Next, we pay attention to the huge variety of living organisms that inhabit the forest. Students try to establish what relationships exist between them. The totality of all relationships Ch. Darwin called the struggle for existence. During the tour we find herbaceous plants and count the number of seeds (fruits) on it. Will all these seeds grow into mature plants? Of course not. Why? If all the seeds crumble in this place and germinate, then in the dense shoots between the seedlings there will be an acute struggle for existence - for moisture, nutrients, light. Ch.Darwin called such struggle intraspecific. Then we pay attention to some oppressed plants of poplar, warty birch, Tatar maple. Why are they like this? C. Darwin argued that complex relationships are established between organisms of different species. This is an interspecies struggle for existence. Plants also struggle with adverse environmental conditions. Many organisms die from severe frosts, fires, heavy rain, and people are sometimes guilty. In the struggle for existence in a population of plants (animals), natural selection occurs: some individuals die, while others survive, give viable offspring, and are characterized by high adaptability to new environmental conditions. I suggest that students establish signs of adaptability of plants and animals to living conditions. The guys are working. Next, we study what adaptations plants have to endure adverse conditions in the autumn-winter period. I draw attention to the beauty of the autumn forest. The students then work in groups to complete the tasks.
Tasks:
tree types
Types of shrubs
Herb types
species name
Morphological features
Physiological signs
environmental signs
Tasks:
1. Make a description of the site: relief, illumination, weather conditions.
2. Determine the main types of trees, shrubs, grasses and identify their suitability for cohabitation. Record the results in a table.
tree types
Types of shrubs
Herb types
Features of adaptation to cohabitation
3. Determine the criteria for one type of tree (shrubs or grasses). Enter the data into a table.
species name
Morphological features
Physiological signs
environmental signs
4. Make a conclusion about the reasons for the diversity of species in nature.
Tasks:
1. Make a description of the site: relief, illumination, weather conditions.
2. Determine the main types of trees, shrubs, grasses and identify their suitability for cohabitation. Record the results in a table.
tree types
Types of shrubs
Herb types
Features of adaptation to cohabitation
3. Determine the criteria for one type of tree (shrubs or grasses). Enter the data into a table.
species name
Morphological features
Physiological signs
environmental signs
4. Make a conclusion about the reasons for the diversity of species in nature.
Tasks:
1. Make a description of the site: relief, illumination, weather conditions.
2. Determine the main types of trees, shrubs, grasses and identify their suitability for cohabitation. Record the results in a table.
tree types
Types of shrubs
Herb types
Features of adaptation to cohabitation
3. Determine the criteria for one type of tree (shrubs or grasses). Enter the data into a table.
species name
Morphological features
Physiological signs
environmental signs
4. Make a conclusion about the reasons for the diversity of species in nature.
