Biology lesson "forms of relationships between organisms". Lesson topic: Interaction of populations of different species Lesson type: combined
Lesson Objectives:
- To form knowledge of the basic biotic relationships as the basis for the existence of living organisms in ecosystems;
- develop the ability to apply general biological patterns to solve non-standard problems; draw your own conclusions;
- to cultivate an understanding of responsibility to the micro and macro world for their activities, which can lead to the destruction of ecosystems.
Textbook: Sivoglazov V.I., Agafonova I.B., Zakharova E.T. General biology. A basic level of. Textbook for grades 10-11 of educational institutions. - M .: Bustard, 2005
Homework: p.5.3 Creative task - to prepare an electronic presentation on the topic: "Biotic factors of the environment."
Epigraph of the lesson:"There is nothing more inventive than nature." Cicero
During the classes
1. Organizational moment
2. Motivational stage.
Teacher: Organism. The smallest virus, tiny bacterium, single-celled algae, green plant... a system created by the forces of nature. And life beyond the complex internal processes There is also ongoing interaction with outside world. Not only abiotic connections, not only the constant need for an influx of energy is important for all living on Earth. Thousands of relationships with other organisms - plants with plants, plants with animals. Sometimes they are secondary, almost imperceptible, but always playing important role in the well-being and very existence of the organism.
Codegram 1
The theme of our lesson is "Biotic factors of the environment." Let's define the purpose of our lesson. (Discussion, work with an epigraph and formulating the purpose of the lesson).
3. Operational-executive stage.
Teacher:
- What is called a habitat?
- What factors are classified as natural factors?
All the effects exerted by living organisms on each other are related to biotic factors. They can be divided into two groups.
Diagram on the board:
Interspecies relations, as a rule, are distinguished by a variety of manifestations. If two species enter into a relationship, then the position of the species at different forms biotic bonds is denoted conventional signs:
- + individuals of the species benefit;
- - individuals experience oppression;
- 0 no influence.
Let's do the exercise completion of task 1 of the application, discussion of the results).
Consider some of the forms of relationships between living organisms.
Predation
Teacher: This is one of the most hostile and extreme forms of relationship, extreme but inevitable. Predation is positive for one species and negative for another.
- typical gathering
- typical predation
- What can be said about the characteristics of predators? (completing task 2 applications).
- feed at the expense of others;
- hunting behavior is characteristic;
- the development cycle is not linked to the victim's development cycle.
- And what features are characteristic of the prey of predators?
Overhead 2
- Why can't predators be exterminated?
Overhead 3
(Discussion of the role of predators in the regulation of population size and completion of task 3 of the appendix).
Conclusion: Predation associated with active search and energetic methods of mastering prey leads to the development of various ecological adaptations (development of sensory organs, quick reaction, running speed - in prey; endurance, running speed, speed of reaction to prey - in predators).
Competition
Teacher: This form of relationship occurs between species with similar ecological needs, each of the species is at a disadvantage, since the presence of the other reduces the possibility of mastering food resources, shelters and other means of subsistence. Forms of competitive interactions can be very diverse: from direct physical struggle to peaceful existence. However, if two species end up in the same community, sooner or later one species will displace the other (Gause's principle of competitive exclusion).
(Performing task 4 of the application, discussion and formulation of the conclusion).
Conclusion: Competition is the only form environmental relations, which negatively affects both interacting partners.
Diagram on the board:
(Solution of task 5 of the application).
- What is degeneration?
(Performing task 6 of the application and formulating a conclusion).
Symbiosis
Teacher: Symbiotic relationships diversify the interspecies bonds in a community, and the more diverse and stronger the bonds, the more stable the community. The forms of symbiotic relationships are as follows:
Overhead 4
(Performance of tasks 7-8 of the application, their discussion).
4. Evaluative-reflexive stage.
Student performance independent work, after the end of which the results are summed up, and reflection is carried out.
Literature:
- Zakharov V.B. General biology: tests, questions, assignments. 9-11 cells - M .: Education, 2003 - p.103
- Petunin O.V. Biology lessons in grade 11. - Yaroslavl: Academy of Development, Academy Holding, 2003.- p. 223-231
- Sergeev B.F. Interesting physiology. Ed. 2nd - M .: Young Guard, 1977 - 304 p.
Equipment: Tables on general biology: “Struggle for existence and its forms”, “Directions of evolution”; tables on botany: “The structure of lichens”, “The legume family”; herbariums of insect pollinated plants, leguminous plants, plants with phytoncidal properties, slide presentation. (Attachment 1)
During the classes
I. Teacher: Any living organism is subject to environmental factors.
Do you remember what these factors are?
Students name: abiotic, biotic, anthropogenic and give them a description.
Teacher: The life of a single organism is impossible without others, its well-being depends, one way or another, on the species interacting with it . There are many examples of such interactions. They can be direct or indirect, unilateral or bilateral. In the courses of botany, zoology, general biology, we talked about these connections, gave examples. And today we will summarize the available facts and get acquainted with new concepts.
Among the huge variety of interactions of living beings, certain relationship types, having much in common in organisms of different systematic groups. The main types of relationships can be depicted in the form of a diagram. ( Slides 3, 4. Attachment 1)
Students write the diagram in notebooks, supplementing the abstract with definitions and examples. Students are given an advanced task - to prepare messages with examples of types of interaction between organisms. They are included in the teacher's explanation.
1. SYMBIOSIS (cohabitation) is a type of relationship in which both partners or one of them benefit from the other. ( slide 5)
Commensalism- a type of relationship in which one of the two species living together benefits from coexistence without harming the other (beneficial for one species, indifferent for the other). ( slide 6)
B) housing. Often the bodies of animals or their habitats serve as a refuge for other species. In the body cavity holothurians (sea cucumber ) - Type Echinoderms - small species of animals find shelter. (Slide 6) The fry hide under umbrellas large jellyfish; in the nests of birds and rodents - a huge number of insects.
1.2. Proto-cooperation is a type of relationship in which coexistence is beneficial to both species, but not necessarily for them.
A) An example would be sea anemone and hermit crab. IN tropical seas sea anemones live at shallow depths - coelenterates, related to coral polyps. They are devoid of a solid skeleton and have the appearance of a small cylinder, bordered at the upper end with a corolla of tentacles; lead a sedentary lifestyle. But you can often see how they slowly move along the bottom. This happens when an anemone settles on an empty shell of a mollusk; a hermit crab finds refuge there, hiding its soft belly in it, and he “carries” a shell with sea anemones. Cohabitation is mutually beneficial: the movement increases the space for catching prey for the sea anemone, part of the prey falls to the bottom and is eaten by cancer. The benefit is obvious, but not necessary: both cancer and anemone can exist separately . (Slide 11)
C) In plants, an example of a mutually beneficial relationship is the cohabitation of nodule bacteria and legumes (peas, beans, peanuts, soybeans, clover, alfalfa), which are able to absorb nitrogen from the air and convert it into ammonia, and then into amino acids. These bacteria settle on the roots, root tissues grow, forming thickenings - nodules. Plants in symbiosis with nitrogen-fixing bacteria can grow on soils poor in nitrogen and enrich the soil with it. That is why legumes are introduced into crop rotation with other crops.
D) Another form of symbiotic relationships in plants - the cohabitation of the fungus with the roots of higher plants - mycorrhiza. The mycelium of the fungus forms a thick layer on the roots of birch, pine, oak, spruce, lingonberry and many perennial herbs. Root hairs on plant roots do not develop, and water and mineral salts are absorbed by the fungus. The mycelium of the fungus penetrates deep into the root, receiving carbohydrates from the partner plant and delivering water and salts to it. Trees with mycorrhiza grow better than without it. (Slide 12)
1.3. Mutualism is a type of relationship in which both species benefit and cannot live independently. This is the strongest relationship between organisms. (Slides 13, 14)
BUT) lichens - are not an independent organism, but an amazing symbiosis of representatives of two kingdoms - a fungus and an algae. Algae supplies the fungus with synthesized organic matter, the fungus protects the algae from drying out, heating, excess sun rays etc., and also supplies her inorganic substances and water. In fact, these relationships are much more complicated.
B) Another example is relationships termites and flagellar protozoa, living in their intestines. Termites feed on wood but lack the enzymes that digest cellulose. Flagellates produce such enzymes; without them, termites die of starvation. And for the simplest - termites provide food and conditions for existence.
C) Human symbionts living in the intestine (Bacteria - E. coli - Escherichia coli etc.) contribute to normal digestion. (Synthesizes vitamin K, prevents the development of pathogenic organisms in the intestine)
D) In plants, an example of mutual relationships is the relationship of insects - pollinators and plants. In nature, there is a wide variety of mutual adaptations that plants and insects have developed. These adaptations are sometimes so narrow that the plant can only be pollinated by a certain type of insect. For example , clover is pollinated by bumblebees , which, having a long proboscis, are able to collect nectar, while simultaneously pollinating plants with a deep corolla, such as clover, bean, labiaceae.
2. NEUTRALISM - a type of relationship in which organisms live together in the same territory, but do not directly affect each other. (Slides 15, 16)
For example, squirrels and moose in the same forest do not contact each other. The interaction can be traced indirectly - through the habitat, food supply, etc.
3. ANTIBIOSIS is a type of relationship in which both interacting populations or one of them is negatively affected.
Predation is a relationship in which members of one species catch and eat members of another species. (Slides 17, 22, 23)
In unicellular - a common occurrence.
Jellyfish - paralyze victims with stinging cells and eat them.
Many predators among insects, arachnids.
Large frogs attack the chicks.
Snakes prey on amphibians, birds, and small mammals.
A special case of predation is cannibalism - eating individuals of their own species, more often juveniles (in fish, some mammals); in spiders, females often eat males after mating.
Natural selection acting in a population of predators will increase the efficiency of finding, catching and eating prey (web of spiders, poisonous teeth of snakes, precise strikes of attacking animals, even complex behavior).
Victims in the process of natural selection improve the means of protection and avoidance of predators ( protective coloration, mimicry, various spikes, needles, shells, behavioral features, etc.).
In the evolution of the “predator-prey” relationship, there is a constant improvement of both predators and their prey.
In plants, the need for nitrogen led to the development of predation. Plants growing on nutrient-poor, water-washed soils have evolved interesting adaptations. For example, members of the family sundews. In Russia - Rosyanka large-leaved. Her leaves are collected in a rosette; the edges of the leaves are covered with glandular hairs, on the edges of which there are droplets of sticky mucus. Flies and other insects stick to them, the leaf twists; under the action of mucus enzymes, insects are “digested”. ( slide 23)
3.2. COMPETITION occurs when two closely related species have similar needs.
Question: Give examples of competition in plants and animals.
Sooner or later, one competitor will supplant the other.
Charles Darwin considered competition one of the most important constituent parts struggle for existence . (Slide 25)
Display tables. Working with the textbook p. 64, p. 2, p. 37, fig. 24 - a cycle of development of a wide tapeworm.
3.4. AMENSALISM - a type of relationship in which for one of the interacting species the consequences are negative, for the other they are indifferent.
An example is the biochemical interaction of woody plants. Chemical emissions - phytoncides - protective substances of plants can be indifferent to neighboring species, harmful and favorable. (Slide 18)
Strong phytoncides also secrete Pine forest- 5 kg per 1 ha, juniper - up to 30 kg per 1 ha, larch - about 2 kg per 1 ha. Phytoncides of oak, poplar, fir can kill the causative agent of diphtheria, and pine secretes substances that help cure tuberculosis.
It has been established that garlic phytoncides will prevent garden strawberries from getting sick with gray rot
Allocate phytoncides and flowers, and leaves, and roots of the plant. A peculiar chemical environment is created around it, which serves the plant as a reliable protection against pathogenic microbes, in addition, it affects the development of neighboring plants (inhibits or stimulates their development). It is well known that not all plants get along with each other. Grapes, for example, do not tolerate the close proximity of radish, cabbage, laurel. If you put a bouquet of tulips and forget-me-nots nearby, then the flowers quickly wither, as they say a depressing effect on each other. Conversely, plants can accelerate the growth of their neighbors, for example, beans accelerate the growth of corn. Rowan and linden, birch and pine grow well nearby.
At different types plants, the degree of impact on the environment and thus on the life of the inhabitants is not the same in accordance with the characteristics of their morphology, biology, seasonal development, etc. Plants that most actively and deeply transform the environment and determine the living conditions for other co-inhabitants are called edificators . There are strong and weak edifiers. Strong edificators include spruce (strong shading, soil depletion in nutrients, etc.), sphagnum mosses (moisture retention and the creation of excess moisture, an increase in acidity, a special temperature regime, etc.). Weak edificators are deciduous species with an openwork crown (birch, ash), plants of the herbaceous cover of forests.
Fixing task. ( Slides 26-30)
Homework: fill in the table (Classification by E. Heskil) “Typology of biotic interactions”.
0 - no interaction;
The organism benefits from the interaction;
Interaction depresses the body
Topic: Relationships of organisms in communities
Target: to study the types of interactions between organisms in ecosystems.
Tasks:
Tutorials: to form students' knowledge about the types of interaction between organisms, to show the dependence of some species on others.
Developing: develop the ability to analyze, draw conclusions, work independently in a group.
Educators: promote the moral education of students, cultivate a culture of communication, a sense of responsibility for the result of their work, a sense of collectivism, empathy, improve group work skills.
Knowledge update.
Hello guys.
The board contains the following tasks:
Find matches.
Plant destroyers
mushroom consumers
Animal producers
bacteria
Find matches
natural communities
Artificial communities
A. garden D. lake
B. steppe E. ocean
V.garden J. aquarium
D. forest W. meadow
Checking knowledge of terms (frontal)
Plant community, life form of plants, species composition.
2.Goal setting
The slide shows an illustration for a fairy tale.
Teacher: What fairy tale does this illustration refer to?
Pupils: Teremok.
In the famous Russian folk tale“Teremok” settled in one house:
frog, mouse, hedgehog, fox and hare and wolf. Can all these animals really be in one “house”. What can connect them?
We will answer these questions after studying the topic of the lesson. And so, the topic of our lesson is “Relationships of organisms in the community”
What goal can we formulate?
Determine what relationships between different species in a biocenosis can exist?
Topic study plan(on the slide.)
There is no such person who would not be worried about the fate of the surrounding nature, and, accordingly, his own fate. The life of any living being is impossible without others. They never live in isolation, but are constantly in contact with each other and living organisms. Therefore, there are different relationships between animals.
4. Mutually beneficial relationship.
4. Discovery of new knowledge
Studying a specific topic make a color cluster(scheme) types of biotic relationships. (4 groups work.)
We work with you for 5 minutes, you can use the textbook paragraph No. 12, while filling out the table with the following content:
| Type of relationship | Definition | |
After studying the type of relationship, characterize it.
Competition - mutually harmful relations in which organisms oppress as a result of the struggle for existence. Along the wheat field adjacent to the edge of the forest, weeds grow: cornflowers, wheatgrass, toadflax. The relationship between cultivated and weeds is also competitive. IN mixed forests fast growing trees will shade and oppress slow growing trees as well as herbaceous plants that require more light and thus crowd them out, depriving them of light and nutrients. An example is the habitation in the same territory of two closely related species - nightingale and bluethroat. As a rule, these species do not live together in the same biotope in nature. (Pike and perch, wolf and fox.)
Mutually beneficial relationship
Symbiosis is a positive relationship. This is a form of relationship in which partners benefit from each other (or one of them from the other).
Anthill of a red forest ant. Symbiosis with aphids - feeding on honeydew aphids. Ants find aphids by crawling up trees. In addition to liquid food (pad), ants eat solid food, most which are insects at all stages of development. Red forest ants are not only symbionts, but also predators. Symbiosis - literally " living together. There are several forms of symbiosis: mutualism, cooperation and commensalism. If the influence of one organism is required for the growth and survival of another, then such a symbiosis is called mutualism. Mutualism- mutually beneficial cohabitation, when the presence of a partner becomes mandatory for the existence of each of them. Mutualistic relationships develop between the hyphae of the fungus and green unicellular algae, which form a new organism - a lichen. Another example of symbiosis can be observed: clover pollinated by bumblebees. The structure of the mouth apparatus of bumblebees is adapted for pollination of closed flowers of leguminous plants.
Hat mushrooms and trees. This is also a symbiotic relationship. gifs cap mushrooms grow into the roots of trees, replacing the lost root hairs, they absorb water, which then enters the conductive vessels of the tree. In return, the tree supplies the fungus with ready-made organic matter. Examples: nodule bacteria on the roots of legumes, lichen, mycorrhiza - a symbiosis of fungus and root, birch and boletus, and others.
Physical education (2-3 exercises).
Practicing training activities
Define the nature of the relationship of organisms in nature, using the notation:
Competitive relations.
The predator-prey relationship.
Mutually beneficial relationship.
deer and elk as carriers of plant seeds;
fungus and algae as part of a lichen;
bullfinches as consumers of plant seeds;
hat mushroom and tree;
tinder fungus and tree;
ants and aphids;
crossbill and squirrel;
cow and grass;
fox and flea;
weeds and cultivated plants.
Let's check the nature of the relationship by mutual checking and put each other's marks. The key is written on the board. (No errors - “5”, 1-2 errors - “4”, 3 errors - “3”.)
6. Reflection
Will be presented in the form of "Daisies of Impressions". What new did you learn in the lesson? What did you like about the lesson? What's not clear? Where will this knowledge be useful to you in practice?
So there are invisible threads life in nature.
Can all these animals really be in one “house”. What can connect them? BUT problematic issue? We answered it with work in the lesson.
Ideal homework
- draw a picture for the topic;
- come up with a biological task on the topic;
- come up with a story, for example, “the life of an organism in new environment habitat"
- creative task: imagine that animals can talk. What problems would they tell people about and what would they ask us to do?
Present your answer in the form of an essay, come up with a title.
I would like to finish the lesson with the words of the mandate: the author is Boris Zakhoder.
“We need everything in the world, we need everything in a row,
Who makes honey and who makes poison
Bad business with a cat without a mouse
A mouse without a cat is no better business
You can’t do without ridiculous monsters
And even without evil and ferocious predators.”
List of used literature
Sukhorukova L.N., Kuchmenko V.S., Biology grade 5-6 - Moscow "Enlightenment" 2012
Lesson topic: Relationships between organisms.
Target: consolidation and deepening of students' knowledge about the variety of types of interaction between living organisms and their significance in the life of species.
Tasks:
Continue the formation of students' cognitive, communicative and health-preserving competencies through:
a system of general ecological concepts about the adaptability of organisms to live together in communities;
illustration of the diversity of biotic relationships between organisms,
the ability to identify types of relationships between organisms, to give a brief description of them.
education of environmental literacy, respect for nature;
Lesson type: combined.
Teaching methods:
verbal (heuristic conversation with elements of independent work);
partial search (performance of independent tasks);
visual (filling in the table and working with illustrations).
Work form: individual, group.
Equipment: projector, screen, computer, presentation, handouts (tests, table "Biotic interactions", cards with tasks for group work).
Lesson plan:
I. Organizational moment.
IV. Homework.
V. Summary of the lesson.
During the classes.
I. Organizational moment.
Greetings, journal entry.
II. Learning new material.
The topic of our today's lesson: "Relationships between organisms" (slide 1). You have already considered this topic more than once, starting with the lessons of the surrounding world and natural history and ending with the lessons of general biology in grade 9, therefore, the main goal of the lesson is to consolidate and deepen knowledge about the variety of types of interaction between living organisms and their significance in the life of species. (slide 2)
Before we start talking about this, let's recall the material of the past lessons, for which I suggest that you complete a small test: (slide 3)
Test "environmental factors"
1. Which of the following factors can be attributed to abiotic:
A - Spring floods of rivers.
B - Deforestation.
B - Fertilizing the soil,
2. A reserve was created in the forest area. To what environmental factor can this fact be attributed?
A - Biotic.
B - Abiotic.
B - Anthropogenic.
3. Under biotic factor understand:
A - The sum of the impact of living organisms.
B - Human impact on organisms.
B - Factors of inanimate nature.
4. From the listed examples, select the anthropogenic factor:
A - Light.
B - Relationships between individuals in a population.
B - Industry development.
5. Dead tree leaves form a litter that serves as a place
habitat and food for many organisms. What factors does this
phenomenon?
A - Anthropogenic.
B - Biotic.
B - Abiotic.
G - Complex action factors.
Exchange the sheets with completed tests with your desk mate and check each other for the correct answers (no errors - “5”;
One mistake - "4";
Two errors - "3";
Three or more errors - "2").
Raise your hands, those who completed the test without errors ... with one error ... with two errors ... with three or more ... (we conclude that the material has been mastered)
We turn to the study of new material.
The life of any living organism is impossible without other organisms. (slide 4). Its well-being depends on the many species that affect it. The whole world of animals, fungi and a significant part of bacteria lives due to the compounds that are created by plants. But plants could not exist without microorganisms, animals - pollinators and seed dispersers, fungi that help feed the roots and other plants that create the necessary microclimate.
Relationships between different organisms are called biotic. All nature is permeated with these connections. They are varied and may direct(carried out with the direct influence of one species on another, for example, a predator on a prey), or indirect(through influences on external environment or other types). (Students in the course of the teacher's explanation make notes in a notebook). Today we will look at the main types of interaction between organisms.
There are several basic types of interactions between organisms. Like most biological categories, they are not concepts with absolutely clear boundaries, and therefore there is no generally accepted definition of them. unified classification. As an example, let's consider the classification "+,0,-". This classification is based on the principle of the influence that some organisms have on others in the process of mutual contacts. These relationships can be denoted by the mathematical symbols "+", "-", "0" (positive, negative, neutral).
Before you are tables (Appendix 1) that must be filled out during the lesson.
Make up all possible combinations that can be used in this classification and fill in the first column of the table (slide 5).
As you can see, in communities of terrestrial and aquatic organisms, relationships can develop, various types(slide 6). Let's consider them in more detail.
We review the slides and answer the questions:
What is the nature of the relationship between the organisms depicted on the slide? Justify your answer.
What is this type of relationship called? Give it a definition.
Many of the types are already known to students from previous biology courses, so the guys call them on their own and give definitions. If difficulties arise or an unknown concept is encountered, the teacher defines and characterizes this type of relationship.
In the course of work, we fill out the table, write down the definitions in a notebook.
In nature, there are often mutually beneficial relationships between species of organisms in which they receive mutual benefits - these are diverse symbiotic relationship.
A prerequisite for a symbiotic relationship is living together, a certain degree of cohabitation of organisms.
Mutualism(obligate symbiosis). (slide 7)
A classic example of symbiosis is lichens, which are a close mutually beneficial cohabitation of fungi and algae. Another example of symbiosis is the relationship between termites and their intestinal cohabitants - flagellates. These protozoa produce an enzyme that breaks down fiber into sugars. Termites do not have their own cellulose-digesting enzymes and would die without symbionts. And flagellates, in turn, find favorable conditions in the intestines that contribute to their survival. They are not found in the free state in nature.
Protocooperation(optional symbiosis). (slide 8)
Wide famous example symbiosis - cohabitation of green plants (primarily trees) and fungi.
One type of mutually beneficial relationship is proto-cooperation (literally: primary cooperation). In this case, coexistence is beneficial for both species, but not necessarily for them, that is, it is not an indispensable condition for their survival. An example is the spread of seeds by ants of some forest plants, pollination by bees of various meadow plants.
Commensalism A form of relationship in which one species gains some advantage without harming or benefiting the other. The basis for this type of relationship can be shared space, substrate, shelter, locomotion, or most commonly food. Using the features of the lifestyle or structure of the host, commensalism derives one-sided benefits from this. Its presence for the owner usually remains indifferent (an example is the dwelling of the Mediterranean carapace fish in the body cavity of some species of holothurians, which it uses as a refuge), large mammals(dogs, deer) serve as carriers of fruits and seeds with hooks (like burdock), without receiving any damage or advantages from this.
lodging() - one organism uses another (or its dwelling) as a place of residence, without causing harm to the latter. (slide 9)
Freeloading- one organism feeds on the remains of the food of another. (slide 10)
Companionship Both species consume different substances or parts of the same food. (slide 11)
Predation - a type of relationship between organisms in which representatives of one species kill and eat representatives of another. (slide 12) For typical predator(wolf, lynx, mink) hunting behavior is characteristic. But besides predators - hunters exist large group predators - gatherers, the way of feeding which consists in a simple search and collection of prey. Such, for example, are many insectivorous birds that gather food on the ground, in grass or on trees. Predation is a widespread form of biotic relationship.
The significance of predation can only be understood by considering this phenomenon at the population level. Long-term communication between predator and prey populations creates their interdependence, which acts like a regulator, preventing too sharp fluctuations in numbers or preventing the accumulation of weakened or sick individuals in populations. In some cases, predation can significantly reduce the negative consequences of interspecific competition and increase the stability and diversity of species in communities.
Under a microscope, he discovered that on a flea
The biting flea lives on a flea;
On that flea is a tiny flea,
Angrily sticks a tooth into a flea
Flea, and so adinfinitum.
Herbivory.(slide 14). Predation is often called any eating of some organisms by others. Consequently, herbivory can also be attributed to one of the forms of predation.
Neutralism Both populations have no effect on each other.(slide 15). Neutralism is the cohabitation of two species in the same territory, which does not have any positive or negative consequences for them. negative consequences. For example, squirrels and moose do not have significant effects on each other.
Antibiosis.
Amensalism(slide 16) - a relationship in which one organism affects another and suppresses its vital activity, while itself does not experience any negative influences from the suppressed. For example, the impossibility of survival of a small light-loving herbaceous plant under the dense shade of a beech or spruce. With amensalism, one species suffers, while the other develops normally: for example, fungus Penicillium secretes penicillin, a substance that inhibits the growth of various bacteria, but the bacteria do not affect the mold fungus. In clinical trials of penicillin, it was found that its use increased the number of fungal diseases, since in natural conditions the development of fungi is inhibited by the presence of bacteria.
allelopathy (slide 17) - a form of antibiosis, in which organisms have a mutually harmful effect on each other, due to their vital factors (for example, excretions of substances). It is found mainly in plants, mosses, fungi. At the same time, the harmful influence of one organism on another is not necessary for its life activity and does not benefit it.
Competition(slide 18) - a form of antibiosis, in which two types of organisms are inherently biological enemies (usually due to a common forage base or disabilities for reproduction). For example, between predators of the same species and the same population or different species that feed on the same food and live in the same territory. Thus, it is possible to distinguish between interspecific and intraspecific competition. In this case, harm done to one organism benefits another, and vice versa.
So, we have considered all possible types of relationships between organisms in nature. Each biocenosis is simultaneously characterized by many different relationships, which is shown in the following diagram (slide 19).
Think and say: what results does all the variety of types of relationships between organisms that we have studied lead to. Students offer their options, highlight the main thing, make notes in notebooks. (slide 20)
III. Consolidation of the studied material.
Group work
Task 1. Solution of practical problems.
Task 1. During mass shooting birds of prey(eagle owls, hawks) the number of partridges and black grouse is decreasing; when wolves are destroyed, the number of deer decreases. How can this be explained?
Answer: the predator has a regulating effect on the prey population, destroying sick and weakened individuals. With a decrease in the predator population, the prey population decreases.
Problem 2. A lot of ferns grew in the forest, but after cutting it down, these plants disappeared. Why?
Answer: Ferns grow in moist, shady places under the forest canopy. Deforestation deprived them of favorable conditions.
Task 3. Sparrows and jackdaws regale themselves with the fruits of cherries. But jackdaws swallow the cherry fruit whole, and sparrows only peck at the juicy pulp of the fruit. Which of these birds is healthier for cherries?
Answer: as a result of a raid by sparrows, the fruits of the cherry will only be spoiled, the seeds in the stones will remain on the parent plant. Jackdaw for cherries is more useful: the bird will swallow the fruit whole, the seed inside the stone will not suffer, then the stone will be exposed to intestinal juices - this will improve the germination of the seed, and then, together with the litter, it will be thrown away from the parent plant, which contributes to the spread of the species.
Task 4. All the old hollow trees were cut down in the forest. Large young trees were eaten by pests. The forest is dead. What is the connection between these phenomena?
Answer: Insectivorous birds lived in hollow trees - hollow nesters and the bats. They were deprived of their homes and left the forest. Then insect pests multiplied in such numbers that they destroyed the remaining trees.
Task 2. Read the list of living organisms and write down the pairs that are in relationships:
symbiotic (group 3)______________________________
competitive (group 2)________________________________
predatory (group 1)_________________________________
Commensalytic (Group 4)___________________________
Linden, oak, clover, dragonfly, bee, porcini mushroom, ladybug, mosquito, frog, hedgehog, Scots pine, common viper, Maybug larva, roundworm, bark beetle, man, squirrel, crow, woodpecker.
Conclusion.
All groups remarkably (or not so much, the teacher assesses together with the students) coped with the proposed tasks. I think everyone will agree with my following words:
The relations of organisms in nature are complex and diverse, and often the line between them is conditional. As a result of the complexity and intertwining of relationships between species, careless human intervention in the life of nature can cause a chain reaction of events that will lead to unexpected and undesirable consequences. Understanding this, a person is obliged to treat nature carefully, carefully, in order to preserve it.
IV. Homework.
§17.4
V. Summary of the lesson.
We mark the most active students, set marks for the work in the lesson.
Attachment 1
Biotic Interactions
Relationship characteristics
Type of relationship
Relationship Examples of this type
+ ; +
Symbiosis
Mutualism (obligate)
Protocooperation (optional)
Mushroom and algae (lichen)
Termites and flagellates
Aphid and ant
Mycorrhiza on tree roots
+ ; 0
Commensalism
lodging
Freeloading
Companionship
Epiphytic plants on tree trunks
Lions and hyenas
Shark and fish stuck
Butterfly and caterpillar on the same plant
+ ; -
Predation
Proper predation
Herbivory (phytophagy)
Wolves and moose
ladybug and aphids
Scabies mite and man
hare and grass
0 ; 0
Neutralism
Squirrels and moose in the same forest
mosquito and birch
0 ; -
Amensalism
Beech and bluebell broadleaf
Spruce and pine
- ; -
Antibiosis
allelopathy
Interspecific competition
Intraspecific competition
Isolation of phytoncides by some shrubs
Fox and wolf
The struggle for territory, the possibility of reproduction, etc.