What is infusoria slipper definition. Infusoria-shoe: external and internal structure, nutrition, reproduction, significance in nature and human life. Infusoria shoe: structure
Type Ciliates, or Ciliary, are the most complex protozoa. On the surface of the body, they have organelles of movement - cilia. There are two nuclei in the ciliate cell: the large nucleus is responsible for nutrition, respiration, movement, metabolism; the small nucleus is involved in the sexual process.
The features of the structure and vital activity of ciliates are considered on the example of ciliates-shoes.
Habitat, structure and movement. In the same reservoirs where the amoeba Proteus and Euglena green live, the ciliate shoe is also found (Fig. 30). This single-celled animal 0.5 mm long has a spindle-shaped body, vaguely resembling a shoe. Infusoria-shoes are always in motion, swimming with a blunt end forward. The movement speed of this animal reaches 2.5 mm per second.
Rice. 30. The structure of infusoria-shoes: 1 - cilia; 2 - contractile vacuole; 3 - cytoplasm; 4 - large core; 5 - small nucleus; b - cell membrane; 7 - cell mouth; 8 - cell pharynx; 9 - digestive vacuole; 10 - powder
The body of the ciliate is more complex than that of the amoeba and euglena. A thin elastic sheath that covers the outside of the ciliate retains the constant shape of its body. This is also facilitated by the burial of the developed supporting filaments, which are located in the layer of the cytoplasm adjacent to the membrane. On the surface of the body of the ciliate there are about 15 thousand oscillating cilia. At the base of each cilium lies a basal body. The movement of each cilium consists of a sharp sweep in one direction and a slower, smooth return to its original position. The cilia oscillate about 30 times per second and, like oars, push the infusoria forward, while the wave-like movement of the cilia is coordinated. When the ciliate shoe floats, it slowly rotates around the longitudinal axis of the body.
Under the elastic sheath, special formations are scattered throughout the body - trichocysts (from the Greek. Trichos - "hair" and cystis - "bubble"). These are short "rods" 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 infect a predator that attacks the shoe. In place of the used trichocysts, new ones appear over time.
Food. On the body of the ciliate there is a depression - the cellular mouth, which passes into the cellular pharynx. Thicker and longer cilia are located near the mouth. They drive bacteria down the throat along with the stream 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 ciliate by the current of the cytoplasm. In the vacuole, food is digested, the digested foods 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.
The slipper ciliate finds its prey by sensing the presence of chemicals that release bacteria clusters.
Selection. In the body of ciliates-shoes there are two contractile vacuoles, which are located at the front and rear 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 outside. The entire cycle of contraction of these vacuoles occurs once every 10-20 seconds. The 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. Slipper ciliates 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 in each new ciliate there is one large and one small nucleus. Each of the two daughter ciliates receives part of the organelles (for example, contractile vacuoles), while others are formed anew. Infusoria-shoes are divided once or twice a day.
Rice. 31. Asexual reproduction (A) and sexual process (B) in a ciliate shoe
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 there merges with the remaining nucleus. Then, in each ciliate, a large and small nucleus 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 - stylonichia; 4 - suvoy
The bursaria has one large and long sausage-like core, there are about 30 small kernels. Most of the ciliates are actively swimming, but some of them, for example, stylonichia, move along the bottom of the reservoir, along aquatic plants, as if walking on special elongated cilia located on the abdominal side of the body ... Other ciliates, such as suvoys, attach to the bottom or to plants with long stalks, which can contract due to special contractile fibers. Many suvoys form colonies. These ciliates feed mainly on bacteria. Sucking ciliates also lead a sedentary, immobile lifestyle. They have no cilia. They are equipped with sucking tentacles in the form of thin contractible tubes, which serve to catch prey (mainly other protozoa) and suck out the contents from it. Protozoa that touch the tentacles, such as flagellates, instantly adhere to them. And then the contents of the victim are sucked in, as if pumped along the tentacle into the sucking ciliate.
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, deer, ciliates in large numbers inhabit the anterior sections of the stomach. These ciliates feed on bacteria, starch grains, fungi, and plant tissue particles. 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 infestation occurs at the time of group feeding or watering.
Laboratory work No. 1
- Topic. The structure and movement of ciliates-shoes. Target. To study the features of the structure and movement of ciliates-shoes.
- Equipment: microscope, tripod magnifier, slides and coverslips, pipette, cotton wool, culture of ciliates-shoes in a test tube.
Working process
- Determine if the ciliates are visible to the naked eye in the test tube.
- Apply a drop of water with infusoria-shoes from a test tube to a microscope 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.
- Place two drops of water with ciliates on a glass slide, connect them with a water "bridge". Place a crystal of salt on the edge of one drop. Explain what is happening.
- Put two or three cotton wool fibers in a drop of water with ciliates (to slow down the movement of ciliates). Cover gently with a coverslip.
- Place the specimen under a microscope. Consider, first at low, and then at high magnification of the microscope, what happens inside the body of the ciliate.
- Sketch the outer and inner structure of the ciliate shoe, using the high magnification of the microscope. Make the necessary designation.
- Based on observations, list the signs that are characteristic of ciliates as representatives of protozoa.
Ciliates are complexly organized protozoa. They have two nuclei in the cell: large and small. They reproduce asexually and sexually. Sexual reproduction promotes renewal, exchange between individuals and redistribution of hereditary (genetic) material, which increases the viability of ciliates.
Exercises on the covered material
- Why is the ciliate shoe so named?
- What signs prove a more complex organization of the ciliate-shoe in comparison with Proteus amoeba and green euglena?
- How is the more complex structure of the ciliate-shoe manifested in the processes of nutrition and excretion than in other protozoa?
- What are the features of the breeding process of ciliates-shoes?
- Why is the sexual process of great biological importance in the life of a ciliate shoe?
For reproduction of ciliates-shoes, its more complex and special structure lays an imprint in comparison with other Protozoa. So, the ciliate shoe has two nuclei. One is the big one called macronucleus, the second is small, called micronucleus.
The nuclei contain chromosomes, which include DNA molecules. They contain hereditary information. In the large nucleus (macronucleus) there are several sets of chromosomes, that is, this is the nucleus polyploid... The small nucleus (micronucleus) contains a double set of chromosomes, that is, this nucleus diploid... For comparison: most other animals have one diploid nucleus in their cages. Only in the germ cells of the nucleus haploid(contain a single set of chromosomes). Diploidy means that each chromosome is duplicated, that is, each chromosome has an identical other chromosome. Polyploidy means that each chromosome is duplicated multiple times.
From the DNA of the macronucleus, information is read with the help of special molecules (RNA) and then in the cytoplasm with the help of RNA proteins characteristic of the ciliate-shoe are synthesized. And then proteins determine the synthesis of fats, carbohydrates and other substances (this is done by proteins that perform the function of enzymes) or cell structures (organelles, membranes, etc.) are built from proteins.
The chromosomes of the micronucleus are not used to regulate cell activity. The micronucleus is used only for the sexual process. The ciliate shoe has not only asexual reproduction, but also sexual reproduction. However, this sexual reproduction proceeds differently from that of multicellular animals. With it, an increase in the number of individuals does not occur. Therefore, sexual reproduction of ciliates is more correctly called the sexual process ( conjugation).
Asexual reproduction of ciliates-shoes
Asexual reproduction of ciliates-shoes proceeds in about the same way as in amoeba and green euglena. The cell divides in two. However, unlike the same euglena, the ciliate does not divide in the longitudinal direction, but in the transverse direction. That is, in a ciliate shoe, one daughter cell gets the front part of the cell, and the second gets the back.
During favorable times of the year (when it is warm and there is a lot of food), division occurs approximately once a day. Asexual reproduction of ciliates-slippers occurs only in grown, fully formed cells-individuals.
Before the cell itself divides, its nuclei are first divided. First, a small nucleus divides, two micronuclei are formed. After that, the macronucleus is divided. At this time, many vital processes in the ciliate shoe are suspended (for example, it stops feeding). One large and one small nucleus go to the front of the cell, the other large and small - to the back of the cell.
After the division of the nuclei, the cell itself begins to divide. In the middle, a constriction is formed, which deepens, completely separating one part of the cell from another. Each new cell receives one contractile vacuole, and completes the second on its own. The cell mouth and other parts of the cell are also built.
The sexual process of ciliates-shoes
In the sexual process (conjugation), two different cells of the ciliate shoe are involved. They fit together from the side of the cell mouths and stick together. A so-called cytoplasmic bridge is formed between them (a channel through which the contents of one cell can flow into another).
The large nuclei of the conjugating ciliates are destroyed. In each ciliate shoe, the small nucleus is divided so that four nuclei are formed with a haploid set of chromosomes. This division is called meiosis... Three of the haploid nuclei are destroyed, and the rest is divided in the usual way ( mitosis). But since it had a haploid set of chromosomes, two nuclei with a haploid set are obtained.
One haploid nucleus leaves each cell along the cytoplasmic bridge into another cell, while the other remains. Thus, slipper ciliates exchange their genetic information. One haploid set remains its own, while the second comes from another cell.
After the exchange of nuclei has taken place, in each cell they merge. A new small diploid nucleus is formed. Then it divides, giving rise to a large nucleus, which then becomes polyploid.
During sexual reproduction, including the sexual process, there is an exchange of genetic information. Individuals may develop new traits that contribute to their better adaptability and survival.
The simplest single-celled living organism is the ciliate shoe. The body length of the microorganism reaches only 0.3 - 0.5 mm. No matter how a person looks at the aquatic environment where the ciliate-shoe lives (reservoirs with stagnant water and home aquariums), he will not be able to see this animal with the naked eye, not only because of its microscopic size, but also its colorless color.
Body structure of ciliates shoes
Body shape ciliates spindle-shaped shoes, resembles appearance the sole of a shoe with a narrow toe and a wide heel counter. The surface of the cell is covered with a thin light elastic membrane - ectoplasm, it is she who keeps the body in a certain constant shape. The inner layer of the membrane is darker, with a granular structure - endoplasm.
Body surface covered with cilia in the amount of 10,000 pieces, constantly moving, due to which the ciliate moves at a speed of 2.5 mm per second. During movement, the cell rotates along the longitudinal axis of its body. Each cilium, in sync with the rest, produces a sharp swing in a single direction and a smooth slow return of the hairs to their initial position.
Between the cilia, trichocysts are located in the membrane sacs - protective organelles consisting of a body with a tip. When a cell is irritated by a predator, trichocysts are thrown out, transforming into strong threads that hit the enemy. New trichocysts grow in the vacated places.
External structure the ciliates of the shoe consist of the upper part and the peritoneum, the latter is distinguished by the presence of a peristome - a kind of perioral recess that resembles a groove. The back of the peristome is equipped with a mouth opening leading to the pharynx. There are also cilia along the edges of the peristome, but longer than on the rest of the body. With their help, a continuous flow of water is created into the pharynx of the animal, along with which bacteria, the main food of the ciliates of the shoe, enter there. A digestive vacuole is formed around the bacteria in the cytoplasm, which is immediately filled with secreted digestive juice. The vacuole breaks off from the pharynx and passes further into the body of the ciliate - towards the posterior end, describes an arc, returns to its original place. The entire vacuole travels in 1 hour, at which time digestive enzymes penetrate into it, and useful substances are absorbed into the cytoplasm. At the end of the path, the remnants of food that did not have time to digest are thrown out.
Feeds on ciliate shoe is almost continuous - a stream of water with microparticles constantly pours into an open mouth. Feeding stops only during the breeding process.
How does an infusoria shoe breathe?
Cell respiration is carried out through the body membrane. Oxygen enters the body, where it oxidizes organic matter, decomposing into CO2, water and other constituents. In the process, energy is released, due to which the life of the cell is maintained. Removal of carbon dioxide generated during respiration also occurs through the envelope.
Excretory system of ciliates shoes
The internal structure of the body of the ciliate shoe includes two vacuoles, they accumulate water saturated with nutrients formed during the oxidative reaction. When the vacuoles are filled to a certain value, they approach the surface of the body as close as possible from the inside, pouring out the contents out through the shell.
Breeding methods for ciliates shoes
The usual way- asexual, occurs by dividing the cell into two equal parts. During active movement, the body of the shoe is stretched in length and a deepening constriction is formed strictly in its middle - the place in which the ciliates are further divided into two organisms. With the appearance of the constriction, the structure of the ciliate of the shoe also changes - two pharynxes, mouth openings and peristomes are formed. Each new cell has one large and one small nucleus, part of the organelles of the mother cell, the missing ones are formed anew. Asexual reproduction occurs rather quickly - in just a day from one ciliate 2 - 4 unicellular animals.
Sexual reproduction- not often used method, but possible in case of temperature changes and lack of food. At the end of the process, the ciliate shoe often transforms into a cyst. Two ciliates temporarily connect, at the point of contact, the shell dissolves, a kind of bridge appears. At this time, each ciliate loses a large nucleus, the small one divides twice, forming 4 daughter nuclei, three of which disappear, the latter is again divided into equal parts. At the end of this, there are 2 nuclei in the body of each ciliate. Each of the cells exchanges one nucleus with the other, which move along the connecting bridge. Once in the body of another ciliate, the nucleus merges there with another one - "native" to this organism. The resulting nuclei are again divided into a large and small nucleus, as it should be, the ciliates are disconnected. This method of reproduction is called conjugation, and its duration is 12 hours. Despite the fact that a new cell is not formed in this case, the benefit of such a process is the exchange of genetic material between individuals, which leads to the redistribution of heredity, renewal and an increase in the viability of organisms.
Features of the behavior of ciliates shoes
An interesting experiment was set up by researchers, proving that ciliates can be trained. When an animal, previously in the dark, tried to move to a bright place, then on the border between light and darkness it received an electric shock, which caused the ciliate to stop and turn back. The experiment was repeated many times and after 45 minutes from its beginning, the shoe, reaching the edge of a dark place, did not wait for an electric shock, but went back into the darkness. Thus, it is possible to develop in animals an addiction to various stimuli. The acquired skills are stored in the memory of the ciliate from 8 to 90 minutes, they can accumulate and help to adapt to a changing environment.
The ciliate shoe is quite sensitive to the temperatures of the surrounding water and knows how to choose the most favorable place for itself, which is shown by the following experience: ciliates were placed in a tube with water, at one end of the tube the water was heated to a temperature of 35 degrees, at the other - up to 15. All shoes gathered in neutral territory, that is, in a place where the water was comfortable for them and had about 25 degrees.
It turned out that the ciliate shoe is sensitive to chemicals and is able to distinguish between their microscopic particles in the aquatic environment. Scientists use this feature of animals to detect certain impurities in water when studying liquids in laboratory conditions.
As for nutrition, here too, the ciliate shoe shows originality - if algae serve as food for it, then the animal tries to stay in the dark, apparently, photosynthesis, which occurs in not completely digested algae, interferes with its digestion.
Breeding ciliates shoes at home
Required inventory: three-liter cans, syringe (the plastic tip should be replaced with the glass part of the pipette), a lens with high magnification, a piece of glass.
Reproduction occurs most rapidly in milk, but microorganisms in it also die for a short time... The dried peel of a ripe banana is more beneficial (3 sq. Cm is enough).
The culture of ciliates can be purchased from aquarium lovers or obtained independently by scooping up water from the bottom of a stagnant reservoir. In the latter version, a drop of water is placed on a glass under a microscope, where ciliates are clearly visible among the protozoa. Clean water should be dripped from the reservoir next to the drop. With the help of a match, a connecting channel is pulled from one drop to another, along which the ciliates themselves will swim into fresher water. Transferring the ciliates again and again into a drop of new water, a pure culture of these microorganisms is obtained.
Then the animals need to be sent to the incubator - half a 3-liter can of pure water is collected, 3 drops of milk are added and the culture of ciliates is placed. The jar is placed in a warm, lit place, but not in direct sunlight. Bacteria serve as food for ciliates, therefore they usually accumulate in particles of organic material. To use the shoes for feeding the fry, algae are lowered into the container, around which ciliates immediately appear, they are collected with a pipette and sent to the aquarium, but not immediately. You should wait a little while the animals eat the bacteria that live in these drops of water, and only then put the liquid with ciliates in an aquarium with fry.
A typical representative of the class of ciliary ciliates is the ciliate shoe or Paramecia (Pagamaecium caudatum; Fig. 1)
The structure and reproduction of ciliates shoes
Infusoria slipper lives in shallow stagnant bodies of water. The shape of the body resembles the sole of a shoe, reaches 0.1-0.3 mm in length, is covered with a strong elastic shell - a pellicle, under which skeletal support threads are located in the ecto- and endoplasm. This structure allows the ciliate to maintain a constant body shape.
The organelles of movement are hair-like cilia (ciliates have 10-15 thousand shoes) that cover the entire body. When examining the cilia using an electron microscope, it was found that each of them consists of several (about 11) filaments. At the heart of each cilium is a basal body located in a transparent ectoplasm. The shoe moves quickly thanks to the coordinated work of the cilia, which rake in water.
In the cytoplasm of the ciliates, ectoplasm and endoplasm are clearly distinguished. In the ectoplasm, between the bases of the cilia of the paramecium, there are organelles of attack and defense - small fusiform bodies - trichocysts. The photographs taken with an electron microscope show that the discarded trichocysts are equipped with nail-like tips. When irritated, the trichocysts are thrown out, turning into a long, elastic thread that affects the enemy or prey.
In the endoplasm are located - two nuclei (large and small) and the systems of the digestive, as well as excretory organelles.
Nutrition organelles... On the so-called abdominal side, there is a pre-oral cavity - a pinnate, leading to the cellular mouth, which passes into the pharynx (cytopharynx), which opens into the endoplasm. Water with bacteria and unicellular algae that the ciliate feeds on is driven through the mouth and pharynx by a special group of peristome cilia into the endoplasm, where it is surrounded by a digestive vacuole. The latter gradually moves along the body of the ciliate. As the vacuole moves, the swallowed bacteria are digested for an hour, first with an acidic, and then with an alkaline reaction. The undigested residue is thrown out through a special hole in the ectoplasm - powder, or anal pore.
Osmoregulatory organelles... At the anterior and posterior ends of the body, at the border of the ecto- and endoplasm, there is one pulsating vacuole (central reservoir), around which 5-7 adducting tubules are located by the corolla. The vacuole is filled with fluid from these adduction channels, after which the fluid-filled vacuole (diastole phase) contracts, pours fluid out through a small opening and collapses (systole phase). Following this, the liquid, which has again filled the leading channels, is poured into the vacuole. The anterior and posterior vacuoles contract alternately. Pulsating vacuoles perform a double function - the release of excess water, which is necessary to maintain a constant osmotic pressure in the body of the Paramecia, and the release of dissimilation products.
Nuclear apparatus shoes represented by at least two qualitatively different nuclei located in the endoplasm. The shape of the nuclei is usually oval.
- The large vegetative nucleus is called the macronucleus. In it, transcription takes place - the synthesis of informational and other forms of RNA on DNA matrices, which go into the cytoplasm, where protein synthesis is carried out on the ribosomes.
- Small generative - micronucleus. Located next to the macronucleus. In it, before each division, the number of chromosomes is doubled, therefore the micronucleus is considered as a "depot" of hereditary information transmitted from generation to generation.
Infusoria-slipper reproduces both asexually and sexually.
- In asexual reproduction, the cell is lacing in half along the equator and reproduction is carried out by transverse division. This is preceded by mitotic division of the small nucleus and processes characteristic of mitosis in the large nucleus.
After repeated asexual reproduction in the life cycle, the sexual process, or conjugation, occurs.
- The sexual process consists in the temporary connection of two individuals by the mouth openings and the exchange of parts of their nuclear apparatus with a small amount of cytoplasm. At the same time, large nuclei disintegrate into parts and gradually dissolve in the cytoplasm. Small nuclei first divide twice, the number of chromosomes is reduced, then three of the four nuclei are destroyed and dissolved in the cytoplasm, and the fourth is divided again. As a result of this division, two haploid reproductive nuclei are formed. One of them - migrating, or male - passes into a neighboring individual and merges with the female (stationary) nucleus that remains in it. The same process takes place in the other conjugant. After the fusion of the male and female nuclei, the diploid set of chromosomes is restored and the ciliates diverge. After that, in each ciliate, a new nucleus is divided into two unequal parts, as a result of which a normal nuclear apparatus is formed - a large and a small nucleus.
Conjugation does not lead to an increase in the number of individuals. Its biological essence consists in the periodic reorganization of the nuclear apparatus, its renewal and an increase in the viability of the ciliate, its adaptability to the environment.
The slipper and some other free-living ciliates feed on bacteria and algae. In turn, ciliates serve as food for fish fry and many invertebrates. Sometimes slippers are bred to feed newly hatched fish fry.
The value of ciliates
Balantidium (Balantidium coli)
Localization... Colon.
Geographic distribution... Everywhere.
There are two contractile vacuoles. The macronucleus is bean-shaped or rod-shaped. A rounded micronucleus lies near its concave surface (Fig. 2). Propagated by transverse division and by conjugation. Cysts are oval or spherical (50-60 microns in diameter).
Domestic and wild pigs are considered the main reservoir of balantidiasis. In some farms, the infection rate reaches 100%.
In the intestines of animals, balantidia are easily encystated, while in the human body, cysts are formed in a relatively small amount. Animals excrete cysts in their faeces and pollute the environment. Pig farm workers can become infected when caring for animals, cleaning livestock premises, etc. The infection of workers in this category is much higher than in other specialties. Cysts in pig feces persist for several weeks. Vegetative forms live for 2-3 days at room temperature.
Infection occurs through contaminated vegetables, fruits, dirty hands, unboiled water.
Pathogenic action... The formation of bleeding ulcers in the intestinal wall, bloody diarrhea. Without treatment, the death rate reaches 30%.
Laboratory diagnostics... Detection in feces of vegetative forms or cysts.
Prevention: compliance with the rules of personal hygiene is of fundamental importance; public - the fight against pollution of the environment with feces of pigs, as well as people, the appropriate organization of working conditions on pig farms, the timely identification and treatment of patients.
The simplest unicellular organisms belonging to the class of ciliates are distributed almost everywhere. From the cold ice of the North to the equally scorching icebergs of the South, these cute creatures are found in any stagnant water, which are one of the most important links in the food chain of the biocenosis. For the ciliate aquarist, slippers are valuable as a good feed for newborn fry. But before you start this living creature in your "underwater world", you should get acquainted with the reproduction, nutrition and life of the microorganism.
Natural habitat and more
The smallest living creatures live in shallow bodies of water with still water. Infusoria shoes are called so for the similarity of the shape of the little body, completely covered with cilia, with a lady's shoe. Cilia help animals move, feed, and even defend themselves. The smallest organism has a size of 0.5 mm, it is impossible to see the infusoria with the naked eye! An interesting way to move in water - only with a rounded blunt end forward, but even with such a kind of "walking", the little ones develop a speed of 2.5 mm / 1 second.
Single-celled creatures have a dual-core structure: the first "large" nucleus controls nutritional and respiratory processes, monitors metabolism and movement, but the "small" nucleus is included only in the processes of sexual significance. The thinnest shell of increased elasticity allows the microorganism to be in its natural, well-defined form, as well as to move quickly. As such, movement is carried out by means of cilia, which play the role of "oars" and constantly push the shoe forward. By the way, the movements of all cilia are absolutely synchronous and consistent.
Livelihoods: nutrition, respiration, reproduction
Like all free-living microorganisms, the ciliate slipper feeds on the smallest bacteria and algae particles. Such a baby has an oral cavity - a deep cavity located in a certain place on the body. The mouth opening goes into the pharynx, and then the food goes straight to the vacuole to digest food, and then the food begins to be processed by the acidic and then alkaline environment. The microorganism also has a hole through which incompletely digested food debris comes out. It is located behind the food hole and, passing through a special type of structure - powder, the remnants of food are pushed out. The nutrition of the microorganism is debugged to the limit, the shoe cannot overeat or remain hungry. This is perhaps one of the perfect creations of nature.
The infusoria's shoe breathes with all the integuments of its body. The released energy is enough for the life support of all processes, and unnecessary waste compounds, such as carbon dioxide, are also removed through the entire body area of the individual. The structure of the ciliate of the shoe is quite complex, for example, the contractile vacuoles, when overflowing with water with dissolved organic substances, rise to the very extreme point plasma on the body and push out all unnecessary. Freshwater inhabitants in this way remove excess water, which constantly flows in from the surrounding space.
Microorganisms of this type can gather in large colonies to places where a lot of bacteria accumulate, but they react extremely sharply to table salt - they float away.
Reproduction
There are two types of microbial reproduction:
- Asexual, which is a common division. This process occurs as the division of one ciliate shoe in two, and new organisms have their own large and small nucleus. Moreover, in new life only a small part of the "old" organelles passes over, all the rest are quickly formed anew.
- Sexual. This type is used only with the appearance of temperature fluctuations, insufficient food and other unfavorable conditions. It is then that animals can split by sex and then turn into a cyst.
It is the second breeding option that is most interesting:
- Two individuals temporarily merge into one;
- At the confluence site, a canal is formed that connects the pair;
- The large nucleus completely disappears (in both individuals), and the small one divides twice.
