Slide 4

Segment structure

Slide 5

Digestive system

• The digestive tract is through. The intestine consists of three functionally different sections: the foregut, midgut and hindgut. Some species have salivary glands.
• The anterior and posterior sections are ectodermal, and the middle section of the digestive system is of endodermal origin.

Slide 6

Mouth opening → pharynx → esophagus → crop → stomach → intestines → anus

Slide 7

Circulatory and respiratory systems

The circulatory system is closed, its basis is made up of dorsal and abdominal vessels, connected by annular vessels that resemble arteries and veins. There is no heart; its role is played by sections of the spinal and circular vessels containing contractile elements. Respiration is cutaneous, in marine species - with the help of gills on parapodia.

Slide 8

Excretory system

Excretory organs are paired metanephridia in each segment.

Slide 9

Nervous system

• The nervous system is composed of a large ganglion - the brain, from which the abdominal nerve chain departs.
• Each segment has its own nerve ganglion.

Slide 10

Reproduction and development

• Annelids are dioecious; some (earthworms, leeches) have developed hermaphroditism for the second time. Development in polychaete worms occurs with the larva - trochophore, in others - direct.
• Worms with a segmented coelom (that is, oligochaetes, polychaetes, but not leeches) are characterized by a high ability to regenerate.

Slide 11

Lifestyle

They live all over the world, in the sea, in fresh water and on land. Marine forms are especially diverse, which are found at different depths down to extremes (up to 10-11 km) and in all latitudes of the World Ocean.

Slide 12

Systematic position and classification

Annelids include from 7,000 to 16,500 species, divided in different classifications into a different number of classes.

Traditional classification involves division into 3 classes:

• Polychaete worms
• Oligochaete worms
• Leeches

Slide 13

Polychaete worms

• Polychaetes or polychaetes are a class of annelids. Currently, this class includes more than 10 thousand species.
• Most representatives are inhabitants of sea waters. Length from 2 mm to 3 m. A distinctive feature is parapodia - lobe-shaped appendages extending from each segment of the body, bearing chitinous setae (chaetes).

Slide 14

Nutrition and reproduction

• Among sessile polychaetes, sedimentators are the most common. They feed on detritus, extracting it from the water column with the help of hunting tentacles, which also serve as gills.
• Free-living polychaetes are detritivores or predators. Detritivores can extract organic matter from the soil by eating it,
• Most often, polychaete worms are dioecious animals. Polychaetes do not develop formed gonads. Germ cells develop from the coelomic epithelium, and after maturation they begin to float into the coelomal cavity. Fertilization is external. A larva emerges from the eggs - a trochophore.
• Some species are capable of reproducing asexually.

Slide 15

Oligochaete worms

• Oligochaete worms (lat. Oligochaeta) are a subclass of annelids from the class of belt worms (Clitellata). Approximately 3,000 species have been described. There are 450 species in Russia.
• Most oligochaete worms live in the soil. Body structure
• Body length from fractions of a mm to 2.5 m (some tropical earthworms). There is a secondary body cavity - the coelom. Body segmentation is well defined inside and outside. Head and parapodia absent. Each body segment contains several pairs of setae. In most species, respiration is cutaneous; gills are not present. The circulatory system is closed.

Slide 16

Nutrition and reproduction

• Most oligochaete worms feed on plant detritus, which they absorb with the soil; several species are predators.
• Oligochaete worms are hermaphrodites. They reproduce through mating. The eggs are fertilized by one of the mating individuals and laid in a specific cocoon consisting of mucus secreted by glandular cells. Then, after development, a fully formed worm emerges from it.
• If the integrity of the worm's body is damaged, only one end, the anterior end, is subject to regeneration. The second end subsequently dies off.

Slide 17

Leeches

• Leeches (lat. Hirudinea) are a subclass of annelids from the class of belt worms (Clitellata). Most representatives live in fresh water bodies. There are about 500 species of leeches known in the world, and 62 species in Russia.
• Structure: the body length of different representatives varies from several millimeters to tens of centimeters. The anterior and posterior ends of the body of leeches bear suckers. At the bottom of the anterior there is an oral opening leading to the pharynx.

Slide 18

Nutrition, movement and reproduction

• Leeches feed on the blood of vertebrates, mollusks, worms, etc.; there are also predator species that do not feed on blood, but swallow the prey whole (for example, mosquito larvae, earthworms).
• The method of movement of leeches is interesting. There are suction cups on both ends of the worm, which it can use to attach itself to underwater objects. The leech attaches itself to them with its front end, bends into an arc, and approaches.
• Leeches are hermaphrodites. Copulation involves two individuals that simultaneously release seed material.

Slide 19

Thank you for your attention!

Annelid worm (Nereis)

View all slides

Description of the presentation by individual slides:

1 slide

Slide description:

Let's start our lesson by checking your homework. You were asked to prepare a report about one of the representatives of the phylum Annelids.

2 slide

Slide description:

Class: Oligochaetes Type ANNELED WORMS, class OLIGOCHETES, or OLIGOCHETES, families ENCHYTRAEIDS (1), TUBULUS (2) and EARTHWORMS (3-7)

3 slide

Slide description:

Let's remember the material we studied. What types of worms did we study in previous lessons? How can they be useful or harmful to the environment and to humans? Questions for the class: Where and when do you find earthworms? What signs associated with earthworms do you know?

4 slide

Slide description:

Oligochaete worms A subclass of annelids from the class of belt worms. Widely known from the subgroup of earthworms. They live in soil, salt or fresh water, some in two environments at once - in water and on land. The class Oligochaete worms unites 4-5 thousand species. Their body length ranges from 0.5 mm to 3 m.

5 slide

Slide description:

6 slide

Slide description:

Body Cavity The body consists essentially of two tubes nested inside one another. The outer tube represents the wall of the body, and the inner tube represents the wall of the digestive tract. The body cavity, lined from the inside with a layer of cells, is located between them. In the cavity fluid (it gives the body elasticity) there are internal organs. Secondary, well developed, filled with coelomic fluid with cellular elements (lymphocytes, etc.). In most species it is divided segment by segment into separate chambers. The earthworm is a three-layered animal.

7 slide

Slide description:

8 slide

Slide description:

Muscles Under the skin there are circular and longitudinal muscles. When the ring muscles contract, the earthworm's body lengthens, becomes thinner, and moves forward. When the longitudinal muscles contract, the back part is pulled towards the front. Movement occurs in waves.

Slide 9

Slide description:

Digestive system. The digestive tract begins with the mouth, followed by the pharynx, esophagus, crop, stomach, intestines and anus.

10 slide

Slide description:

Circulatory system. Designed to move oxygen, carbon dioxide, nutrients and other substances inside the body. In an earthworm, blood does not flow freely into the body cavity, but moves only inside the vessels. Such a circulatory system is called closed. The circulatory system consists of two main vessels: dorsal and abdominal. Blood flows forward through the spinal cord, and backward through the abdominal tract. In the region of the esophagus, these vessels are connected by ring vessels called “hearts”. They have muscular walls, with the help of which they pump blood into the abdominal vessel. Small blood vessels extend to all organs and to the walls of the body.

11 slide

Slide description:

Reproduction and development An earthworm is capable of reproducing both asexually and sexually. During asexual reproduction, the earthworm's body splits into two parts, and then, through regeneration, each of them “completes” the missing parts of the body. Sexual reproduction occurs with the participation of two individuals who, in contact, exchange seminal fluid with male reproductive cells (spermatozoa). In the front part of the body there is a girdle (thickening of several segments).

12 slide

Slide description:

Charles Darwin became interested in earthworms as a young man. In 1837, he made a report at the Geological Society of London on the topic: “On the formation of the soil layer,” in which he outlined the theory according to which soil particles are constantly carried by earthworms from the depths to the surface, due to which objects lying on the ground end up on after a few years at a depth of 6–10 cm under the turf. Thus, the entire soil layer ends up passing through the stomach of the earthworms. Charles Darwin was struck by the following observations: worms pull leaves into a hole by grabbing them by the top (not by the petiole), so the leaf offers the least resistance when dragged into the hole (after all, the top of the leaf is narrower than its base). But pine needles are always pulled by the worms by the petiole, that is, the base common to double needles. And in this case the object offers the least resistance.

Slide 13

Slide description:

What conclusions can be drawn from the following facts: 1. Earthworms avoid dry soil and always stay in moist soil. 2. Do earthworms crawl out of their burrows on the soil surface at night or during the day, after rain? 3. A sunbeam was pointed at the earthworm with a magnifying glass. The worm moves away from the bright light into the darkness. A stick soaked in vinegar was brought to the front end of the body. The worm turns away from the stick. What causes the earthworm's reactions? What is their biological significance? 4. Darwin in his work “The Formation of the Vegetative Layer of the Earth” wrote: “Earthworms in the history of the formation of the earth’s crust played a much more important role than it might seem at first…”. Why did Darwin write about earthworms this way?

Subject:

"Pylum Annelids".

• Giant earthworms. They live only in Australia, and only in one region of this country - in South-Eastern Victoria. Giant worms were discovered and described in the distant past 1878 researcher and biologist Frederick McCoy.
• It’s hard to imagine, but this giant of the world of worms can reach 1.5-3 meters in length, 2-4 cm in girth and weigh about 700 grams. From a distance, such a worm can easily be mistaken for a long and thin snake; only when you get closer, the characteristic ring-segments inherent in all earthworms become noticeable. The number of the latter reaches 300 pieces.

Three-layer, bilaterally symmetrical; the skin-muscular sac is formed by longitudinal, transverse, oblique muscles, limits the secondary body cavity (in general), filled with liquid; each segment has outgrowths - parapodia.

Aphrodite (sea mouse)

Body cavity of annelids

in general

• Annelids have systems: muscular, open digestive, nervous (there are sense organs - vision, touch, taste, smell, hearing, balance), closed circulatory system, excretory, sexual (dioecious and fake hermaphrodites )
• Predators, saprotrophs
• Move due to parapodia and muscle contraction

• Complex structure determines complex behavior and lifestyle

TYPE RINGED WORMS

class polychaete

LEECH class

(polychotes)

• Nereid
• Aphrodite
• Peskozhil
• serpula

Class

Olychaetes

(oligohunts)

• Earthworm
• tubifex

• About 7000 species of polychaete worms. Most of them live in the seas, a few live in fresh waters, in the litter of tropical forests. In the seas they live on the bottom, where they crawl among stones, corals, and burrow into silt. Among them there are sessile forms and free-living ones. Mobile worms are mainly predators.

• Like all annelids, the body of Polychaetes consists of segments, the number of which in different species varies from 5 before 800.
• Polychaete worms have a head section and an anal lobe.
• On the sides of each body segment there are noticeable skin-muscular outgrowths - organs of movement, which are called parapodia. The worm is raking in parapodia from front to back, clinging to the unevenness of the substrate, and thus crawls forward.

nereid

Sea mouse (Aphrodite)

Nereis

Sessile form of sea worm

But there are also deep-sea ones.

Giant rift worms.

They live in huge colonies around underwater thermal wells.

These worms do not have a digestive system - they are provided with food by colonies of bacteria living in them, and the worms themselves deliver oxygen and sulfur-rich compounds to the bacteria.

head

segments

parapodia

eyes

mustache

tentacles

palpi

jaws

• Skin-muscle bag consists of thin cuticles , skin epithelium And muscles. Located under the skin epithelium two layers of muscles: transverse (circular) and longitudinal. Under the muscle layer there is a single-layer internal epithelium, which lines the secondary body cavity from the inside and forms partitions between the segments.

Digestive system

• The digestive system begins mouth, which is located on the ventral side of the head lobe, continues with the muscular throat(many predatory worms have chitinous teeth in it, which serve to capture prey).

• The throat follows esophagus And stomach .

• The intestine consists of three sections: foregut, midgut and hindgut. Anal hole located on the anal blade.
• Free-living polychaete worms are mainly predators, feeding on crustaceans, mollusks, coelenterates and worms. Sessile fish feed on small organic particles and plankton suspended in water.

• In polychaete worms, gas exchange (oxygen absorption and carbon dioxide release) occurs either the entire surface of the body, or areas of parapodia into which blood vessels extend. In some sessile forms, the respiratory function is performed by the corolla of the tentacles on the head lobe.

• Circulatory system in annelids closed: in any part of the worm's body blood flows only through vessels .
• There are two main vessels - dorsal And abdominal(one vessel passes above the intestine, the other below it), which are interconnected by numerous semi-circular vessels. No heart , and the movement of blood is ensured by contractions of the walls of the spinal vessel, in which blood flows from back to front, in the abdominal - from front to back.

excretory system

• The excretory system is represented by paired tubes located in each segment of the body.
• Each tube begins with a wide funnel facing the body cavity. The edges of the funnel are lined with flickering cilia. The opposite end of the tube opens outward on the side of the body. With the help of a system of excretory tubules, waste products that accumulate in the coelomic fluid are removed to the outside.

• The nervous system consists of paired suprapharyngeal nodes (ganglia), connected by cords into a peripharyngeal ring, a paired abdominal nerve cord and nerves extending from them.
• Sense organs are most developed in free-living polychaete worms. On the head of these worms there are a pair of palps, a pair of tentacles and antennae. These are the organs of touch and chemical sense. Many of them have eyes. There are organs of balance.

• Most polychaete worms dioecious. Gonads are present in almost every segment. Mature germ cells (in females - eggs, in males - sperm) enter first as a whole, and then through the tubules of the excretory system into the water.
• External fertilization. The egg develops into a larva that swims using cilia. Then it settles to the bottom and turns into an adult worm.

• Nereid larva and its transformation into a worm

• Some species reproduce and asexually. In some species, the worm is divided crosswise, and each half restores the missing part. In others, the daughter individuals do not diverge, and as a result a chain is formed that includes up to 30 individuals, but then it falls apart.

Development

• Polychaete worms occur with alternating life forms. Their larvae not alike on adults.
• Some Polychaete worms show care for their offspring (for example, they guard laid eggs).

Larvae of polychaete worms (trochopores)

• The importance of polychaete worms in nature is quite great: they filter water, purifying it; They are the orderlies of reservoirs, destroying a lot of decaying residues. Polychaete annelids are eaten by crustaceans, fish, echinoderms, and coelenterates.

Earthworm Letter

Hello!

I would really like to say: “Hello, dear friends!”, but I’m afraid you won’t like it: after all, not everyone wants to be friends with an ordinary underground worm! And I really want to find friends. I dare to assure you: we earthworms deserve, if not love, then deep respect for our tireless work. We help you people grow crops, loosen the soil, eat old leaves. Some say they don't like our appearance: "Slippery like a worm"; "Writtles like a worm." What's wrong with that? We are slippery and long because it helps us crawl underground. We can't fly! If we didn't squirm, we wouldn't be able to crawl. Dear children! If you want to be friends with me, then I will come to visit you.

« Sincerely, the underground dweller is an earthworm.

It is highly doubtful that there are other animals

(except for earthworms), which in the history of the earth

the barks would occupy such a prominent place.”

Charles Darwin

What do you think the scientist meant?

Class Oligochaetes (Oligochetes) (oligohunts)

Class POLOCHETATES TYPE Annelids SUBTYPE Belt CLASS Oligochaetes SQUAD

Higher Ligochaetes FAMILY Lumbricidae Earthworm

• VIEW
• From the polychaete worms the oligochaete worms evolved.

The Class Oligochaete worms include 4-5 thousand species.

The most common types of earthworms are: 1. Earthworm tetrahedral

(Eiseniella tetraedra) 2. Earthworm is smelly

(Eisenia foetida) 3. Earthworm yellowish-green

(Allophora chlorotica) 4. Earthworm is reddish

(Lumbricus rubellus) 5. Terrestrial or common earthworm

• (creep) (Lumbricus terrestris) The length of their body ranges from 0.5 mm to 3 m. The number of segments in different types of oligochaete worms ranges from 5-7 to 600. All segments their bodies the same . In sexually mature individuals, a thickening appears in the anterior third of the body - .

• glandular girdle They do not have parapodia or antennae, and each segment has two pairs of dorsal and two pairs of ventral. The setae are the remains of the supporting elements of the disappeared parapodia that their ancestors had. The small number of bristles on the body of these worms gave the name to the whole class - Oligochaetes.
• The bristles are so small that they can only be detected by touch by running your finger from the back of the worm's body to the front (the figure shows the abdominal setae at 100 (1) and 300 (2) times magnification).

• The bristles serve these worms when moving in the soil: curved from front to back, they help the worm stay in the hole and quickly move forward.
• The glandular cells of the worm's skin epithelium secrete mucus, which protects the skin from drying out and helps it move through the soil.

• The skin and the muscle layer, in close contact with each other, form skin-muscle sac. Between it and the internal organs there is a fluid-filled secondary body cavity (coelom) .
• Directly under the skin are circular muscles, and deeper – more powerful longitudinal .

• When the circular muscles contract, the body of the worm elongates in length.
• Contraction of the longitudinal muscles shortens the body. The alternation of such contractions ensures the advancement of the worm in the soil.

Digestive system

• The digestive system includes mouth, pharynx, esophagus, mid and hind intestines, anus .

Moving through the soil, the earthworm swallows its particles, passing them through the intestines, as if eating its way, and at the same time assimilating the nutritional particles contained in it.

Ducts empty into the esophagus calcareous glands, substances secreted by these glands neutralize soil acids.

Selection

Isolation - segmental nephridia (metanephridia).

• Gas exchange in oligochaete worms occurs the entire surface of the body. After heavy rain, when water floods the worm holes and air access to the soil is difficult, earthworms crawl out to the soil surface.

• The circulatory system of earthworms is distinguished by the fact that it contains muscular ring vessels capable of contraction - "hearts" located in 7-13 segments.

• The nervous system consists of peripharyngeal nerve ring and ventral nerve cord .
• Each segment has a nerve ganglion with nerves extending from it.

Due to the underground way of life, the sense organs of oligochaete worms are developed. weak. The organs of touch are sensory cells located in the skin. There are also cells that perceive light.

• Unlike Polychaete worms, Oligochaetes are hermaphrodites .
• Their reproductive system is located in several segments of the anterior part of the body. The testes lie in front of the ovaries.
• Sexual reproduction occurs with the participation of two individuals. When they come into contact, they exchange germ cells (the sperm of each of the two worms is transferred to special cavities - the seminal receptacles of the other).
• There is a clearly visible swelling on the front of the worm's body - belt .

• The glandular cells of the girdle secrete mucus, which, when dried, forms a muff. Eggs are first laid in it, and then sperm come from the seminal receptacles.
• Fertilization of eggs occurs in the coupling. After fertilization, the sleeve slides off the body of the worm, becomes compacted and turns into an egg cocoon, in which the eggs develop. Once development is complete, small worms emerge from the eggs.

• The earthworm has a well-developed ability to restore lost or damaged body parts - regeneration .
• If the worm's body is divided in two, then both parts will be able to exist independently, and the lost organs will be restored after some time.

Role in nature and human life

Types of annelids listed in the Red Book Russian Federation

• It's hopelessly difficult Life of a simple worm: Straighten up – The bird will peck Looking from afar. The worm listens sensitively - Where the shovel is there is a knock and a clink; Thoughts are the same: Suddenly it will cut Half for nothing! Collected by fisherman Chervyakov without further ado: Once the bait - Not fake It must be a significant catch. In the rain - with jets of water Floods all the passages It's a pity that the holes Without constipation - How far is it from trouble? In heavy rain - barely alive, Poking my head into the ground, Through the streams Crooked An earthworm weaves its way.

Eizenia salairica

• has about 400 species. Leeches are descended from oligochaete annelids. The body length of leeches is from several millimeters up to 15 cm.
• Representatives of this class are characterized by the following characteristics: constant number of body segments (33), presence of suction cups , absence of bristles on the body.

• The body of the leech is flattened in the dorsal-abdominal direction, with two suckers - perioral and posterior. There is a mouth in the center of the front sucker, and the back one serves only for attachment.

Externally, leeches are similar to other annelids, but they do not have bristles. The method of movement of leeches is connected with this: they move by alternately attaching suction cups to different objects and bending in a loop; many leeches are capable of swimming.

• Leeches lack parapodia, setae, tentacles and gills. On the anterior segments of animals there are from one to five pairs of eyes.
• Under the epithelium of leeches there are circular and very strong longitudinal muscles.

• Blood-sucking leeches in the oral cavity have sharp chitinous teeth. The salivary glands of leeches secrete a special substance - hirudin, which prevents blood clotting both in the wound on the victim’s body and in the stomach of the leech itself (therefore, wounds caused by leeches bleed for a long time).

• The stomach has so-called pockets for storing sucked blood. Therefore, the time intervals between meals for leeches can be very long - up to several weeks.

• Breathing is carried out through the entire surface of the body.

Nervous system and sensory organs

Leeches have a better developed nervous system than other worms. The sense organs perceive light, chemical, mechanical and other stimuli.

• Leeches - hermaphrodites. After mating, they lay numerous cocoons containing varying numbers of eggs.

Homework

§ 17 -18, workbook § 17 -18 and summarize.

Messages:

1) Gastropods.

2) Interesting facts from the life of gastropods.

3) Class bivalve molluscs.

4) Interesting facts from the life of bivalve mollusks.

• Earthworms live in soil rich in humus.
• Earthworms are hermaphrodites.
• The anal opening of the earthworm is located on the 16th segment.
• The skin is covered with a cuticle, and each segment has 16 bristles.
• Earthworms are predators.
• The skin of an earthworm has many mucous and poisonous glands.
• The phylum of Annelids is divided into classes: Oligochaetes, Polychaetes.
• Among the various worms, Annelids are the most progressive group.
• The musculature of an earthworm is formed by longitudinal and circular muscles.
• Oligochaetes play an important role in soil formation, decomposing organic residues.

Choose the correct ones from the proposed judgments

Oligochaete worms. From polychaete worms, oligochaete worms evolved. The class Oligochaete worms unites 4-5 thousand species. Their body length ranges from 0.5 mm to 3 m. Oligochaete worms mainly live in the soil, but there are also freshwater forms. A typical representative living in the soil is the earthworm. It has an elongated, cylindrical body. Small forms are about 0.5 mm, the largest representative reaches almost 3 m (giant earthworm from Australia). Each segment has 8 setae, arranged in four pairs on the lateral sides of the segments. Clinging to uneven soil, the worm moves forward with the help of the muscles of the skin-muscular sac.

Dimensions: 960 x 720 pixels, format: jpg.

You can download the entire presentation “Classes of annelids.pptx” in a zip archive of 6724 KB in size.

Download presentation

Annelids

“Classes of annelids” - From polychaete worms, oligochaete worms evolved. The head lobe is armed with appendages - tentacles and carries small eyes. Polychaetes are the main food supply for marine fish. Meaning. Few live in fresh waters, on the floor of tropical forests. Nervous system. Reproduction of earthworms.

"Earthworms" - Reaction to irritation (sugar). What is the body of an earthworm covered with? Earthworm. How to distinguish the anterior and posterior ends of the body? Reaction to irritation (vinegar). Therefore, the body of the worm is elongated, streamlined in shape, and the skin is covered with mucus. An earthworm lives in the soil. The most famous representative of leeches is the medical one.

https://accounts.google.com

Slide captions:

Presentation for a biology lesson in 7th grade on the topic “Type Annelids. class oligochaete worms" (Umk Pasechnika) Completed by a biology teacher at MBOU secondary school No. 120, Moskovsky district, Kazan Part 1 2015

There is no doubt that there are hardly any other animals that would have played such an important role in the history of the world as these lowly organized creatures. Darwin Ch., (1881)

Are earthworms really low-order creatures?

Purpose of the lesson: To study the features of the external and internal organization of the earthworm, as a representative of the class of oligochaetes, such as annelids, their role in nature and human life.

Classes of annelids

The most common types of earthworms are: 1. Tetrahedra earthworm (Eiseniella tetraedra) 2. Foul-smelling earthworm (Eisenia foetida) 3. Yellowish-green earthworm (Allophora chlorotica) 4. Reddish earthworm (Lumbricus rubellus) 5. Earthworm terrestrial or common (crawl) (Lumbricus terrestris)

Laboratory work “External structure of an earthworm”

setae External structure 120-150 segments

Warm up for the eyes Warm up for the eyes

"Earthworms" - Reaction to irritation (sugar). What is the body of an earthworm covered with? Earthworm. How to distinguish the anterior and posterior ends of the body? Reaction to irritation (vinegar). Therefore, the body of the worm is elongated, streamlined in shape, and the skin is covered with mucus. An earthworm lives in the soil. The most famous representative of leeches is the medical one.

Presentation for a biology lesson in 7th grade on the topic “Type Annelids. class oligochaete worms" (Umk Pasechnika) Completed by a biology teacher at MBOU Secondary School No. 120 of the Moskovsky district of Kazan Part 2 2015

Organ systems (independent work with the textbook)

Ectoderm Mesoderm Endoderm Coelom Secondary body cavity

cuticle skin epithelium longitudinal muscles circular muscles Muscular sac

Digestive system Anus

“Hearts” abdominal vessel dorsal vessel annular vessels Circulatory system Why, although the earthworm does not have a heart, the textbooks contain the expression: “... through a closed circulatory system, blood moves thanks to the contractions of the “hearts” ...”?

Excretory system Excretory funnels - metanephridia

Nervous system Periopharyngeal nerve ring Ventral nerve cord Suprapharyngeal ganglion Subpharyngeal ganglion

Reproductive system Testes (♂) Ovaries (♀) Both hermaphrodites and dioecious are found Girdle

Sexual reproduction

Adult worm and development of young worms in a cocoon

The role of earthworms in nature: The cycle of substances in nature They form humus - humus (an organic part of the soil rich in nutrients) - “bread” for plants (98% soil nitrogen, 60% phosphorus, 80% potassium and other mineral elements for plant growth ) Link in the food chain Form soil drainage Disinfect the soil Loosen the soil Create soil ventilation Prepare the soil for plant growth

The role of earthworms in human life: 1. Humus (organic) fertilizer. 2. BAS (biologically active substances - essential amino acids, enzymes, vitamins) are used in: veterinary medicine, pharmacology, cosmetology, agriculture, biotechnological industries. 3. Food for fish and pets. 4. Protein flour, canned food. 5. Processing of manure and waste. 6. Study of regeneration processes

Wormworm Vermiculture

Vermifarm

Conclusions The body is divided into segments. Most have body outgrowths - bristles. They have a primary and secondary body cavity. The skin-muscle sac consists of skin, circular and longitudinal muscles. The nervous system consists of the peripharyngeal ring and the ventral nerve cord. The circulatory system is closed and consists of vessels. Breathing is carried out over the entire surface of the body. The digestive system is continuous. The excretory system is represented by metanephridia.

Rate your work in the lesson: “5” - learned the theoretical material, completed everything in the laboratory work, worked throughout the lesson; “4” - had difficulty studying theoretical material or performing laboratory work, but worked actively throughout the lesson; “3” - there were difficulties in completing all the tasks; by the end of the lesson I still didn’t understand anything. Need individual help

Homework Paragraph 9 Assignment in workbooks 1-3 on p. 16 to prepare a report about sea worms or leeches (optional). http://www.youtube.com/watch?v=TB94dkCgu_U http://www.youtube.com/watch?v=zlcvyNcs3Cw http://www.youtube.com/watch?v=-WpqyI-u1Gw