Description of methodological development
1. Lesson on the topic:
Type Flatworms. White planaria. (using DER and ICT tools)
2. Combined lesson. In addition to the abstract, a presentation of the lesson with the expressed stages of the lesson is presented.
This lesson uses handouts, a crossword puzzle, video clips and audio clips. In addition, the questions, crossword and tables used during the lesson are provided with answers using hyperlinks. Thanks to this, the lesson becomes very detailed and easy to use, both for the teacher and for the student.
3. Subject-biology Grade 7. Animals.
4. For students of the 7th grade of the educational institution.
5.Classroom form of work.
6. Full description of the development
Lesson on the topic:
Type Flatworms. white planaria.
Tasks:
1. get acquainted with the features of the external and internal structure, the lifestyle of free-living flatworms;
2. to identify the similarities and differences between flatworms and coelenterates;
3. compose general signs of the type Flatworms;
4. Get acquainted with new terms: mesoderm, parenchyma, bilateral symmetry; develop concepts: tissue and organ, organ system.
Means of education : Presentation of the lesson, table "Flatworms", CER in biology, multimedia-ICT room, handouts.
The main content of the lesson:
1. General information about flatworms (bilateral symmetry of the body, three layers).
2. Habitats and representatives of free-living flatworms. Variety of flatworms.
3. Features of the external structure of free-living flatworms, due to the habitat.
4. Features of the internal structure and life processes.
5. Features of a higher degree of organization in comparison with the coelenterates.
During the classes
Knowledge update
2.Individual oral verification-survey with a discussion of questions and verification of answers on the presentation of the lesson. 1. What are the similarities between coelenterates and protozoa?
Coelenterates and protozoa have several similar features:
1. Habitat predominantly in aquatic habitat
2.cellular structure
3.heterotrophic nutrition
4. similarity of the processes of respiration and nutrition
5. similarity of the cells of the inner layer with
the structure of protozoa
What is the practical significance of coelenterates?
Intestinal animals:
1. regulate the number of fish, crustaceans in nature;
2. create coral reefs and their associated communities;
3. Coral skeletons are used to make lime, fertilizers, bijouterie and ornaments, etc.
4. objects of experiments (regeneration, etc.)
5.Used for food in Southeast Asia(Jellyfish in Japan and China)
What are the general signs of intestinal?
1. beam symmetry of the body;
2. two-layer structure;
3. the presence of an intestinal cavity;
4.primitive nervous system;
5.presence of stinging cells;
6. heterotrophs, predators;
7.aquatic habitat
8.two life forms: attached and movable.
Student message (text)
planaria
Planarians are flatworms (Platodes), which belong to the class of ciliary worms, or turbellarians (Turbellaria), to the groupTriclada.
These are small flatworms that are constantly found in freshwater bodies, where they crawl among aquatic plants. A characteristic feature of planarians is a cover of the thinnest cilia covering their body. The mouth opening is placed on the ventral side, and the intestines consist of branches with numerous branches and do not have an anus. All planarians are hermaphrodites.
In the northern and central strip of the USSR it is very commonmilky white planaria (Dendrocoelumlacteum), the largest among others (up to 3 cm), with a completely white body, through which the dark branched intestine clearly shines through (Fig. 171). A pair of eyes can be seen on the head.
Even more common everywhere in stagnant water much smallerbrown planaria (Planariatorva) brown in color with a rounded head end, which also has two eyes. Often found black planaria ( PolycelisNigra) with a rounded head end, along the edge of which sits a row of eyes. Finally, in flowing waters livesmourning planaria (Planarialugubris), also dark in color, but distinguished by its characteristic head end, which looks like an obtuse triangle.
When fishing for planarians, you should take more aquatic plants into the net, which are subject to careful inspection. However, planarians are often overlooked by beginners due to their small size, dull coloration, and slow movement. An exception is the milky-white planaria, which usually catches the eye with its color. Most often, planarians can be found on the underside of floating water lily leaves.
Crawling under water on solid objects, the worm moves forward extremely smoothly, slowly and evenly, as if swimming, without any visible effort. The reason for this peculiar movement is the cilia covering the body of the animal, which are invisible to the naked eye. Planarians secrete an abundant slimy mass that envelops the objects on which they sit. When moving, the cilia rest against this mucous tape, pushing the body of the animal forward. Small species can, in addition, swim freely with the help of paddle-like strikes of cilia on the water.
Planarians feed on small aquatic animals and are quite active predators. They do not refuse to fall. In captivity, white bread is also eaten. The mouth is on the ventral side and leads into a movable extensible pharynx, which can protrude outward like a tube. The intestine has an extremely branched shape, which can be observed especially well in the milky-white planaria when viewed through a magnifying glass in transmitted light.
Planarians reproduce by eggs, which are enclosed in a round or oval cocoon slightly larger than a pinhead, brownish in color. Such cocoons are attached to underwater objects, and in some species they are attached to the substrate on special stalks.
4. Identification of similarities and differences between flatworms and coelenterates.
Students fill in the table in the notebook "Comparative characteristics of coelenterates and flatworms" and draw a conclusion from it.
They reveal the features of a higher degree of organization of organisms in comparison with the Coelenterates.
5. Features of the internal structure and life processes. appearance of tissues and organs. Sexual reproduction. Planarian regeneration.
(Teacher's story with elements of conversation on presentation slides)
3. Consolidation of knowledge
Independent work of students according to the table "Internal structure of the white planaria."
|
| The organs that form the system |
|
Estimated completed table:
| The name of the system of internal organs of the planaria | The organs that form the system | Functions of the organ system |
| 1.nervous | Head ganglions and longitudinal nerve trunks connected by nerve bridges | Perception of stimuli from the environment and from internal organs. The body's response to irritation |
| digestive | Mouth, pharynx, intestines | Capture and digestion of food |
| 3. excretory | fire cells, excretory tubules, canals and pores. | Excretion of liquid metabolic products |
| 4.sexual | Testes are tubular ducts. Paired ovaries-oviducts | Reproduction, increase in numbers |
4 Homework
1. Study §15 of the textbook, answer orally the questions after §.
2. Write out the definitions in a notebook: "hermaphrodite", "parenchyma", "muscular skin sac".
5. Generalization of knowledge on the topic of the lesson:
Features of the structure of flatworms. The complication of their structure in comparison with the intestinal.
Formulate a conclusion with students (reflecting in the presentation). Curriculum 2 foreign language 3 domestic history 17
People sometimes carelessly treat helminthic invasion as an unpleasant, but quite easily tolerated ailment. Accordingly, their beliefs do not call for extreme caution when coming into contact with any kind of dirt, poorly processed food, or contact with pets.
Such criminal negligence has its sad results. Worms are capable of killing their prey, apart from pain and organ damage. The most dangerous are helminths that feed on blood and nutrients inside a person.
Malarial plasmodium destroys blood cells and can bring the victim to death.
Consequences of infection:
- development of malignant tumors;
- immunity weakens;
- metabolism is disrupted.
Manifestations of helminthic invasion are very different from each other. But they also have common symptoms:
- muscle pain that weakens and swells;
- joints hurt, although they were not injured;
- the liver and spleen increase in size;
- skin rash;
- heat.
To them you can add:
Worms sometimes bring the body of an infected person into such a state that a full healthy life, even after their removal, is no longer possible. Therefore, if you find any of the symptoms, you should immediately consult a doctor.
Photo of worms that can live in you
Symptoms of their presence are not immediately and not all pronounced. A long stay of worms will bring the body to chronic diseases. It is believed that many diseases begin with worms. Before you start treatment, you should first know your inner enemy, so as not to fight blindly.
Worms that settle in a person are divided into types:
- roundworms;
- tapeworms;
- flukes.
Below are photos of worms in the human body:
Thanks to such materials, smart people are more armed to protect themselves and their loved ones. But no one should do anything himself in the destruction of uninvited "guests".
Useful video
Below we offer to watch a documentary on the symptoms and infection with worms:
The vast majority of helminths have a negative effect on the general well-being and health of a person, provoking the development of very serious diseases. Keeping this in mind, when the first signs of malaise appear, which do not go away with the treatment of a cold or skin rash with headaches, you should consult a doctor for an appointment for diagnosis.
How to prevent worm infestation? Is it necessary to constantly limit yourself in one or another vacation, literally “squeezing” your life in a vise by observing complex postulates?
But everyone needs to start with themselves, because all modern achievements mean nothing if you simply neglect personal hygiene and preventive measures for those family members who live in our house. Being attentive to your health, detecting in time (if an infection has occurred), competently and promptly proceeding to treatment - all this will help prevent a big personal disaster and the spread of the disease in your environment.
The main classes, structure, nutrition and reproduction. Radial symmetry in the organization of coelenterates in relation to lifestyle. Metagenesis in hydroid and scyphoid polyps. The significance of movement in the origin of the muscular and nervous systems with sense organs in jellyfish. Coral polyps, distribution and biological significance. Ctenophores are separated into a separate type). Phylogeny of coelenterates.
REFERENCES: 2, p. 66-84.
Questions for self-examination
1. Describe coelenterates as multicellular animals.
Why are animals of this type called intestinal?
What classes is the type of coelenterates divided into?
Coelenterates lifestyle (nutrition, reproduction, development, ability to regenerate, etc.).
The value of coelenterates in the overall evolution of multicellular animals.
flatworms
General characteristics and division into main classes.
Ciliary worms Morphology and phylogeny of ciliary worms. The origin of bilateral (bilateral) symmetry in the organization of worms and its significance in the evolution of animals.
Flukes (trematodes). (Monogeneans are classified as a separate type).
Reproduction, development with alternation of generations and change of owners. Correlation between ontogeny and phylogeny in flukes. The main representatives of trematodes, the cycles of their development and the diseases they cause in domestic animals and humans. Fight against flukes.
Tapeworms (cestodes). Their structure, reproduction and development (ontogenesis), fertility. Tapeworms and tapeworms, their most important representatives and development cycles. Tapeworms as causative agents of parasitic diseases in animals and humans. Fight against cestodes. The significance of the works of K. I. Scriabin
roundworms
General characteristics and division into main classes: nematodes.
annelids
Rings are like higher worms. Metamerism as the main feature of the organization of annelids. The origin of the secondary cavity of the body, the circulatory system and their significance in evolution. Development and structure of the ganglionic nervous system of annelids. The main classes of annelids. Polychaete. Features of the structure and lifestyle of polychaetes (polychaetes). Their importance in fish nutrition. Small-bristle (oligochaetes). The role of annelids in the formation of soil and its fertility.
Phylogeny of annelids and their significance in the evolution of invertebrates. The role of Russian scientists in the history of the study of annelids. (I. I. Mechnikov, A. O. Kovalevsky, P. P. Ivanov)
REFERENCES: 2, p. 327-351.
Questions for self-examination
Classification of worms into separate types (flat, round and annelids).
List the main signs of differences (according to organ systems) of the types of flat, round and annelids.
Origin and relationship of various types of worms with other groups of invertebrates (flatworms with coelenterates, kinship of annelids with arthropods, etc.).
Give a general description and classification of flatworms.
Describe the structure, reproduction and development of flukes (hepatic fasciola), tapeworms (broad tapeworm, pork and bovine tapeworms) and echinococcus.
Give a general description and classification of roundworms.
Describe the structure, nutrition, reproduction and development of roundworms using the example of a horse roundworm.
Give a general description and classification of higher annelids.
Describe the structure and biology of annulus using the example of an earthworm.
"Round and flatworms" - The structure of the lanceolate fluke. Flukes class. The first three-layer animals with bilateral, or bilateral symmetry. The body is covered with a dense layer of elastic cuticle, the muscles are only longitudinal. Cross section of a nematode. Filina Diplax Epiphanes. The space between the organs is filled with loose connective tissue (parenchyma) and fluid.
"Ciliary worms" - A typical representative of the ciliary worms is a free-living worm - a white planaria. The reproductive system in animals first appears in ciliary worms. The skin-muscular sac is a characteristic feature of most worms. Flatworms. Terrestrial ciliary worm rhynchodemus. Regeneration of ciliary worms.
"Type Flatworms" - The digestive system begins with an oral sucker and a sucking-type pharynx. Along with intestinal cavities, intracellular digestion has been preserved. Circulatory system: There is no circulatory system. The nervous system is of an orthogonal type, resembling a grid. The sense organs are most well developed in free-living turbellarians.
"Test Flatworms" - 8. Skin - muscular sac formed: Ciliary worms flukes tapeworms. 6. Flatworms have: 3. What class of flatworms does the liver fluke, Siberian fluke belong to: 7. Flatworms: Test: Flatworms. Give a definition. 11. Distribute by class: Attachment organs are characteristic for:
In total there are 7 presentations in the topic
Why are flatworms so named?
Flatworms got their name because of the specific shape of the body.
Which flatworms are dangerous to humans?
For humans, bovine tapeworm, echinococcus, pork tapeworm are dangerous.
Questions
1. What are the differences between flatworms and coelenterates?
Flatworms, unlike coelenterates, have bilateral body symmetry. Their body is made up of several layers. Organs appeared.
2. What features of the structure and life make it possible to divide the type of flatworms into classes?
Dividing the type of flatworms into classes allows the features of the external structure of the body, specific features of the internal structure, different development cycles and habitats.
3. Why do tapeworms lack digestive organs?
Prevention of helminthiases are the following measures:
Compliance with the rules of personal hygiene (washing hands before eating)
Using only quality food
Sufficient heat treatment of meat.
5. Flatworm larvae are able to move independently. What does it matter?
The mobility of the larvae facilitates the rapid search for an intermediate host.
Tasks
Using various sources of information, prepare a report on modern achievements in helminthology.
Helminthology
Applied problems cover: a detailed study of all pathological and morphological and pathological and physiological processes associated with the infection of humans, useful animals and plants with various helminths, in order to find the most effective methods for diagnosing, preventing and treating diseases caused by them, Main sections of Helminthology: General Helminthology (study of Helminthology, fauna , morphology, taxonomy, biological cycles and physiology of helminths); medical Helminthology (human helminthiases, measures to combat them); Veterinary Helminthology (helminthiases of domestic and game animals, measures to combat them); agronomic Helminthology, or phytohelminthology (the study of the effect of helminths on a plant, the development of measures to combat phytohelminths).
