"Types of protozoa" - Euglena lives in fresh water. Infusoria-trumpeter. Then the mother colony collapses, and the daughter colonies begin an independent existence. The outer membrane, together with compacted ectoplasm, can form a pellicle. In autumn, macrogametes and microgametes are formed from generative zooids.

"Type Ciliary" - The ability to name and show the organelles of ciliates. At the stage of "Challenge" - actualization of knowledge. At the stage of "Reflection" the analysis of new information was carried out. Lesson stages. Brief self-analysis of the lesson. Goals. Challenge stage. Fizkultminutka. Type of lesson: mastering new knowledge. Stage "Comprehension". Type of infusoria or ciliary.

"Lesson protozoa" - Theme of the educational project Protozoa are one of the first on Earth. Question of the educational topic: What are the biological features of protozoa? How do protozoa react to environmental influences? What can be found in the droplets of aquarium and pond water? Subjects: Biology, ecology, geography, informatics.

"Protozoa" - The protozoa include animals consisting of one or more cells - colonies. History reference. Type classification Protozoa. Number of species Lifestyle Structure Habitat Example Value. Variety of animals. representatives of the simplest. Class Sarcodaceae (Rhizopods). Flagella class.

"Test protozoa" - Conjugation. They have a variety of shapes and symmetry. Chloroplasts. Powder. Breath. Light sensitive eye. Cilia. 3rd lot Class Infusoria. Pseudopods. Biological auction "Protozoa". Characteristic features of protozoa. Cyst formation. Euglena nutrition. The structure of ciliates-shoes. Big core.

"The simplest organisms" - Find in the picture: Pseudopods Contractile vacuole Nucleus Cytoplasm Digestive vacuole. The type of sarcoflagellates is represented by two classes: sarcode and flagella. Suggest a name. Tasks. Subkingdom unicellular or Protozoa. Subkingdom Unicellular or Protozoa. Class Flagellates Volvox colony.

In total there are 17 presentations in the topic

Type Ciliates, or Ciliary, are the most complexly organized protozoa. On the surface of the body they have organelles of movement - cilia. There are two nuclei in the ciliate cell: a large nucleus is responsible for nutrition, respiration, movement, and metabolism; the small nucleus is involved in the sexual process.

Features of the structure and vital activity of ciliates are considered on the example of ciliates-shoes.

Habitat, structure and locomotion. In the same reservoirs where the amoeba proteus and green euglena live, the infusoria shoe is also found (Fig. 30). This unicellular animal, 0.5 mm long, has a spindle-shaped body, vaguely resembling a shoe. Ciliates-shoes are always in motion, swimming with a blunt end forward. The speed of movement of this animal reaches 2.5 mm per second.

Rice. 30. The structure of ciliates-shoes: 1 - cilia; 2 - contractile vacuole; 3 - cytoplasm; 4 - large core; 5 - small core; b - cell membrane; 7 - cell mouth; 8 - cell pharynx; 9 - digestive vacuole; 10 - powder

The organism of ciliates is more complicated than that of amoeba and euglena. The thin elastic shell that covers the outside of the ciliate maintains a constant shape of its body. This also contributes to the burial of the developed supporting fibrils, which are located in the layer of cytoplasm adjacent to the shell. About 15 thousand oscillating cilia are located on the surface of the body of the ciliate. At the base of each cilium lies a basal body. The movement of each eyelash consists of a sharp stroke in one direction and a slower, smoother return to its original position. The cilia vibrate about 30 times per second and, like oars, push the ciliate forward, while the wave-like movement of the cilia is coordinated. When the ciliate-shoe swims, it slowly rotates around the longitudinal axis of the body.

Under the elastic membrane, special formations are scattered all over the body - trichocysts (from the Greek trichos - “hair” and cystis - “bubble”). These are short "sticks" located in one layer perpendicular to the surface of the body. In case of danger, trichocysts are thrown out with force, turning into thin long elastic threads that hit a predator attacking the shoe. In place of the used trichocysts, new ones arise over time.

Nutrition. On the body of the ciliate there is a recess - a cellular mouth, which passes into the cellular pharynx. Around the mouth are thicker and longer cilia. They drive bacteria into the throat along with the flow of water - the main food of the shoe. At the bottom of the pharynx, food enters the digestive vacuole. Digestive vacuoles move in the body of the ciliates by the current of the cytoplasm. In the vacuole, food is digested, the digested products enter the cytoplasm and are used for life. The undigested residues remaining in the digestive vacuole are thrown out at the posterior end of the body through a special structure - powder.

Slipper ciliates locate their prey by sensing the presence of chemicals that are released by clusters of bacteria.

Selection. In the body of ciliates-shoes there are two contractile vacuoles, which are located at the anterior and posterior ends of the body. Each vacuole consists of a central reservoir and 5-7 channels directed to these reservoirs. First, the channels are filled with liquid, then it enters the central reservoir, and then the liquid is expelled out. The entire contraction cycle of these vacuoles takes place once in 10-20 seconds. Contractile vacuoles bring out harmful substances that are formed in the body, and excess water.

Breath. Like other free-living unicellular animals, ciliates breathe through the integument of the body.

Reproduction. Sexual process. Ciliates-shoes usually reproduce asexually - by dividing in two (Fig. 31, A). However, unlike flagellates, ciliates divide across the body. The nuclei are divided into two parts, and each new ciliate contains one large and one small nucleus. Each of the two daughter ciliates receives part of the organelles (for example, contractile vacuoles), while the others are formed anew. Infusoria-shoes are divided once or twice a day.

Rice. 31. Asexual reproduction (A) and sexual process (B) in ciliates-shoes

During the sexual process, an increase in the number of individuals does not occur. Two ciliates are temporarily connected to each other (Fig. 31, B). At the point of contact, the membrane dissolves, and a connecting bridge from the cytoplasm is formed between the animals. The large nucleus of each ciliate disappears. The small nucleus divides twice, and four daughter nuclei are formed in each ciliate. Three of them are destroyed, and the fourth is divided again. As a result, two nuclei remain in each ciliate. One of these nuclei of each of the two individuals passes through the cytoplasmic bridge into another ciliate (that is, an exchange of nuclei occurs) and merges with the remaining nucleus there. Then, in each ciliate, large and small nuclei are formed from this newly formed nucleus, and the ciliates diverge. This sexual process is called conjugation. It lasts about 12 hours.

The sexual process leads to renewal, exchange between individuals and redistribution of hereditary (genetic) material, which increases the viability of organisms.

Rice. 32. Variety of ciliates: 1 - bursaria; 2 - stentor; 3 - stilonychia; 4 - suvoyka

The bursaria has one large and long sausage-shaped core, about 30 small cores. Most ciliates swim actively, but some of them, such as stylonichia, move along the bottom of the reservoir, along aquatic plants, as if walking on special elongated cilia located on the ventral side of the body . Other ciliates, such as suvoys, are attached to the bottom or to plants with long stems, which can contract due to special contractile fibers. Many suvoyki form colonies. These ciliates feed mainly on bacteria. Sucking ciliates also lead a sedentary, motionless lifestyle. They don't have eyelashes. They are equipped with sucking tentacles in the form of thin contractile tubes that serve to catch prey (mainly other protozoa) and suck out the contents from it. Protozoa that touch the tentacles, such as flagellates, instantly stick to them. And then the contents of the victim are sucked in, as if pumped along the tentacle into the sucking infusoria.

Rice. 33. Protozoa from the stomach of ungulates

Some ciliates live in the intestines of large herbivorous ungulates (Fig. 33). In cows, sheep, goats, antelopes, and deer, ciliates inhabit the anterior sections of the stomach in large numbers. These ciliates feed on bacteria, starch grains, fungi, particles of plant tissues. Larger ciliates devour smaller ones. In other parts of the stomach of herbivores, ciliates are digested. Thus, these ciliates benefit those animals in whose stomachs they live. Infusoria infection occurs at the time of group feeding or watering.

Lab #1

1. Subject. The structure and movement of ciliates-shoes. Target. To study the features of the structure and movement of ciliates-shoes.
2. Equipment: microscope, tripod magnifier, glass slide and coverslip, pipette, cotton wool, culture of infusoria-shoes in a test tube.

Working process

1. Establish whether ciliates-shoes are visible to the naked eye in a test tube.
2. Place a drop of water with infusoria-shoes from a test tube on a glass slide. Consider with a magnifying glass the shape of the body, the external structure, the difference between the front of the body and the back, the way of movement. Count the number of ciliates in a drop of water.
3. Place two drops of water with ciliates on a glass slide, connect them with a water "bridge". Put a crystal of salt on the edge of one drop. Explain what is happening.
4. In a drop of water with ciliates, put two or three cotton fibers (to slow down the movement of ciliates). Cover carefully with a cover slip.
5. Place the slide under the microscope. Consider first at low and then at high magnification of the microscope what is happening inside the body of the ciliate.
6. Sketch the external and internal structure of the ciliates-shoes, using the high magnification of the microscope. Make the necessary notation.
7. Based on observations, list the signs characteristic of ciliates as representatives of protozoa.

Ciliates are complexly organized protozoa. They have two nuclei in the cell: a large and a small one. They reproduce asexually and sexually. Sexual reproduction promotes renewal, exchange between individuals and redistribution of hereditary (genetic) material, which increases the vitality of ciliates.

Lesson learned exercises

1. Why is the ciliate shoe so named?
2. What signs prove a more complex organization of the ciliates-shoes compared to the amoeba proteus and green euglena?
3. How does the more complex structure of ciliates-shoes manifest itself in the processes of nutrition and excretion, than in other protozoa?
4. What are the features of the reproduction process of ciliates-shoes?
5. Why is the sexual process important biologically in the life of ciliates-shoes?

Protozoa - the oldest group of living organisms. When the first protozoa arose is not known. In Western literature, protozoa are not considered as animals and are assigned to the kingdom of protists. And according to the latest systems, several kingdoms are distinguished among the simplest.

Features of the vital activity of protozoa:

The role of protozoa in nature and human life:

free-living representativeamoeba common.A cell of a typical eukaryotic structure, 0.2-0.7 mm in size. The amoeba lives in freshwater, muddy reservoirs. The cytoplasm forms outgrowths - pseudopodia, or pseudopods, which serve for movement and phagocytosis. The amoeba has digestive and contractile vacuoles. It performs all the functions of an independent organism.

tsetse fly

A patient with sleeping sickness in the last stages of the disease, bitten by a tsetse fly

For further development, they must enter the stomach of a malarial mosquito that has bitten a person with malaria. In the mosquito's stomach, male and female gametes mature and then copulate. A mobile zygote is formed. After repeated division of the zygote, sporozoites are formed, enclosed in a shell. Then the shell is destroyed, the sporocysts pass into the body cavity, and later - into the salivary glands of the mosquito.

type of infusoria. Class Ciliary ciliates

Infusoria shoe- representative of the class, has a size of 0.1-0.3 mm. (Ciliates are known about 6 thousand species.)

Distinctive features of these animals:

• the pellicle is covered with cilia that serve for locomotion;
• in the ectoplasm of the shell are trichocysts - protection organs of infusoria;
• there are two nuclei in the cell - vegetative, polyploid (macronucleus) and generative, diploid (micronucleus);
• the oral recess on the body forms an oral funnel (peristome), passing into a cellular mouth (cytostomy), leading to the pharynx, where digestive vacuoles are formed that digest food;
• undigested residues are removed through the powder;
• two contractile vacuoles are located at opposite ends of the body, excess water and metabolic products are excreted through them.

Reproduction of ciliates occurs asexually, by longitudinal cell division. The sexual process is also interesting in ciliates: a cytoplasmic bridge is formed between two individuals, the macronuclei are destroyed, and the micronuclei are divided by meiosis with the formation of four haploid nuclei, three of which die, and the fourth is divided in half, but already by mitosis, forming two nuclei: one is stationary, the other - migratory. Then between the ciliates there is an exchange of migrating nuclei. Then the stationary and migrating nuclei merge, the individuals disperse, and micro- and macronuclei are again formed in them.

Infusoria shoe - the simplest living moving cell. Life on Earth is distinguished by the diversity of living organisms that live on it, sometimes having the most complex structure and a whole set of physiology and life features that help them survive in this world full of dangers.

But among organic beings there are also such unique creations of nature, the structure of which is extremely primitive, but it was they who once upon a time, billions of years ago, gave impetus to the development of life and more complex organisms in all their diversity originated from them.

The primitive forms of organic life that now exist on earth include infusoria slipper, belonging to unicellular creatures from the group of alveolates.

It owes its original name to the shape of its spindle-shaped body, vaguely resembling the sole of an ordinary shoe with wide, blunt and narrower ends.

Such microorganisms are considered by scientists to be highly organized protozoa of class of ciliates, shoes are the most typical variety.

The shoe owes its name to the infusoria due to the structure of its body in the shape of a foot.

Slippers are usually bred in abundance in shallow fresh water bodies with calm stagnant water, provided that this environment contains an abundance of organic decaying compounds: aquatic plants, dead living organisms, ordinary silt.

Even a home aquarium can become an environment suitable for their life activity, only it is possible to detect and carefully examine such living creatures only under a microscope, taking silt-rich water as a prototype.

Infusoria shoes – protozoa living organisms, called differently: tailed paramecia, are indeed extremely small, and their size is only from 1 to 5 tenths of a millimeter.

In fact, they are separate, colorless in color, biological cells, the main internal organelles of which are two nuclei, called: large and small.

As seen on the enlarged photo of infusoria shoes, on the outer surface of such microscopic organisms there are, located in longitudinal rows, the smallest formations called cilia, which serve as organs of movement for shoes.

The number of such small legs is huge and ranges from 10 to 15 thousand, at the base of each of them there is an attached basal body, and in the immediate vicinity of the parasonal sac, drawn in by a protective membrane.

The structure of the shoe infusoria, despite its apparent simplicity at a superficial examination, it has enough complexities. Outside, such a walking cell is protected by the thinnest elastic shell, which helps its body to maintain a constant shape. As well as protective supporting fibers located in a layer of dense cytoplasm adjacent to the membrane.

Its cytoskeleton, in addition to all of the above, consists of: microtubules, alveolar cisterns; basal bodies with cilia and nearby, without them; fibrils and filaments, as well as other organelles. Thanks to the cytoskeleton, and unlike another representative of the protozoa - amoeba, infusoria slipper unable to change the shape of the body.

The nature and lifestyle of ciliates shoes

These microscopic creatures are usually in constant undulating motion, picking up a speed of about two and a half millimeters per second, which for such negligible creatures is 5-10 times their body length.

The movement of ciliates shoes carried out by blunt ends forward, while it tends to rotate around the axis of its own body.

The shoe, sharply waving its cilia-legs and smoothly returning them to their place, works with such organs of movement like oars in a boat. Moreover, the number of such strokes has a frequency of about three dozen times per second.

As for the internal organelles of the shoe, the large ciliate nucleus is involved in metabolism, movement, respiration and nutrition, and the small one is responsible for the reproduction process.

The breathing of these simplest creatures is carried out as follows: oxygen enters the cytoplasm through the integument of the body, where, with the help of this chemical element, organic substances are oxidized and converted into carbon dioxide, water and other compounds.

And as a result of these reactions, energy is generated that is used by the microorganism for its life activity. After all, harmful carbon dioxide is removed from the cell through its surface.

Feature of ciliates shoes, as a microscopic living cell, consists in the ability of these tiny organisms to respond to the external environment: mechanical and chemical influences, moisture, heat and light.

On the one hand, they tend to move to accumulations of bacteria to carry out their life and nutrition, but on the other hand, the harmful secretions of these microorganisms make the ciliates swim away from them.

The shoes also react to salt water, from which they rush to move away, but they willingly move towards heat and light, but unlike euglena, infusoria slipper so primitive that it does not have a light-sensitive eye.

Feeding ciliates slippers

Plant cells and a variety of bacteria, found in abundance in the aquatic environment, form the basis food infusoria shoes. And she carries out this process with the help of a small cellular recess, which is a kind of mouth that sucks in food, which then enters the cellular pharynx.

And from it into the digestive vacuole - an organelle in which organic food is digested. Substances that have entered inside are subjected to hourly processing when exposed first to an acidic and then to an alkaline environment.

After that, the nutrient substance is transferred by currents of the cytoplasm to all parts of the body of the ciliate. And the waste is brought out through a kind of formation - powder, which is placed behind the mouth opening.

In ciliates, excess water entering the body is removed through contractile vacuoles located in front and behind this organic formation. They collect not only water, but also waste substances. When their number reaches the limit value, they pour out.

Reproduction and lifespan

The process of reproduction of such primitive living organisms occurs both sexually and asexually, and the small nucleus is directly and actively involved in the process of reproduction in both cases.

The asexual form of reproduction is extremely primitive and occurs through the most common division of the organism into two parts that are similar to each other in everything. At the very beginning of the process, two nuclei are formed inside the body of the ciliate.

Then there is a division into a pair of daughter cells, each of which receives its part organelles ciliates shoes, and what is missing in each of the new organisms are formed anew, which makes it possible for these protozoa to carry out their vital activity in the future.

Sexually, these microscopic creatures usually begin to reproduce only in exceptional cases. This can happen when there is a sudden onset of life-threatening conditions, such as a sudden cold snap or lack of nutrition.

And after the implementation of the described process, in some cases, both microorganisms participating in the contact can turn into a cyst, plunging into a state of complete suspended animation, which makes it possible for the body to exist in adverse conditions for a sufficiently long period, lasting up to ten years. But under normal conditions, the age of ciliates is short, and, as a rule, they are not able to live for more than a day.

During sexual reproduction, two microorganisms join together for a while, which leads to a redistribution of genetic material, resulting in an increase in the vitality of both individuals.

Such a state is called conjugation by scientists and lasts for about half a day. During this redistribution, the number of cells does not increase, but only the exchange of hereditary information between them takes place.

During the connection of two microorganisms, the protective shell between them dissolves and disappears, and a connecting bridge appears instead. Then the large nuclei of two cells disappear, and the small ones divide twice.

Thus, four new nuclei are created. Further, all of them, except for one, are destroyed, and the latter is again divided in two. The exchange of the remaining nuclei occurs along the cytoplasmic bridge, and from the resulting material, newly born nuclei, both large and small, arise. After that, the ciliates diverge from each other.

The simplest living organisms perform their functions in the general cycle of life. functions, ciliates shoes destroy many types of bacteria and themselves serve as food for small invertebrate animal organisms. Sometimes these protozoa are specially bred as food for the fry of some aquarium fish.

The type of Ciliates is also commonly called Ciliated - the organs of movement of these protozoa are cilia. The ciliate cell has two nuclei, they are called small and large. The first regulates the process of reproduction, and the second is responsible for the processes of nutrition, movement and respiration.

Features of the life of this type should be considered on the example of ciliates-shoes.

Movement and breathing

The infusoria-shoe, whose length is approximately 0.5 mm, chooses water bodies as its habitat. The shape of the body of the simplest is easy to guess by the name - it resembles a shoe. The movement speed is approximately 2.5 mm per second.

The presence of an outer elastic shell provides a stable body shape.

In the cytoplasm, which is adjacent to the shell, there are supporting fibers, their development is a guarantee of the preservation of the constant form of the ciliate.

On the surface of the ciliates there are 15 thousand cilia, at their base there is a basal body. The movement occurs with the help of vibrations of the cilia: they produce about 30 strokes per second, thereby pushing the ciliate-shoe forward.

It breathes through the surface of the body.

Nutrition

A feature of ciliates is the presence cell mouth, near which there are especially long and dense cilia. The cellular mouth continues with the cellular pharynx: cilia push water and ciliate food - bacteria into it.

The infusoria senses chemicals, which releases a cluster of bacteria. Thus, she seeks prey.

The food then ends up in the digestive vacuole where it is digested. From here it follows already into the cytoplasm.

Selection

Selection is carried out using two contractile vacuoles, one is located at the front end, and the other is located at the rear. Vacuoles consist of a reservoir and channels.

The liquid fills the channels, then follows the central reservoir, after which it exits the infusoria. The process of contraction of vacuoles takes 10-20 seconds.

reproduction

The infusoria reproduces asexually - it is divided in two. Its feature is division across the body.

The nuclei of ciliates are divided into two parts: newly formed ciliates have a small and a large nucleus. Daughter ciliates possess parts of organoids, and the missing ones are formed independently. Reproduction occurs several times a day.

For ciliates-shoes, sexual reproduction is also possible, but in this case there is no increase in the number of individuals. Temporarily, the protozoa are connected, forming a connecting bridge from the cytoplasm.

In each individual, the large nucleus disappears, and the small ones are divided twice - four nuclei appear. Of these, only one nucleus remains, which also divides. An individual contains two nuclei, then an exchange of nuclei occurs - one of the nuclei moves to another individual.

There it merges with the nucleus that remains, and thus a small and larger nucleus is formed in each of the individuals. This process, called conjugation, is necessary for the renewal of genetic material between individuals.

Types of ciliates

Ciliates are complexly organized protozoa, there are approximately 7,000 species of them.