After I re-read the author's text about my program for the second time, I still had the feeling of an unaccepted linguoenuresis. Deciding to still download and test this program, I re-read the annotation again. This attempt also did not bring success in the final understanding of the purpose of the program, therefore it was downloaded and installed without delay (look for the text with the description below). And what would you think? The program turned out...

…an offline RSS application that downloads feed headlines generated by ameba.ru. First you have to register an account on ameba.ru. When registering, you can specify what type of news you want to read. No sources of information are mentioned.

Having noted three points, installed. But at startup, the program still downloaded all the news. I had to remove the checkboxes that were unnecessary for me in the channel selection menu, nevertheless, there was a feeling that the program still downloads all the titles, but only shows the marked ones.

Headings can be customized by changing the highlight color and font, as well as making the list translucent. You can watch news for 1, 2 and 3 past days. Judging by the links that the program sends me to, most of the news is accumulated from lenta.ru.

In general, the program is still far from software 2.0, it's just an offline viewer for news feeds on the original site. But below I give the text of the description itself from the developer's website, and whether you download it or not is up to you.

Amoeba is the first program with artificial intelligence that learns itself by adopting the habits of its owner and, thanks to which, over time it becomes more and more indispensable and convenient. The most important and fresh news that is needed not by your neighbors, but by you. A lot of information services that do not concern some American Bill, but directly to you.

Amoeba can be called software 2.0, all because the program is made based on your wishes, namely, on the wishes of direct users, and not some higher mind. This is a program that will change, guided only by the opinions and wishes of those for whom it was created.

The dysenteric amoeba was first described by the Russian scientist L.F. Lesh (1875).

The structure of the dysenteric amoeba.

Amoeba exists in various forms.

Large vegetative form of the amoeba .

The large vegetative form of the amoeba is larger, its size is 20 - 60 microns. The amoeba cytoplasm is divided into 2 layers: outer and inner. The amoeba is transparent, colorless, the nucleus of a living amoeba is not visible. In a dead and immobile amoeba, the nucleus appears as an annular cluster of shiny grains. The endoplasm often contains one to several red blood cells in various stages of digestion, which is very typical of the amoeba form. Such an amoeba is often called a hematophagus, or an erythrophage (erythrocyte eater). Differs from other types of amoeba in translational movement. Under a microscope, one can see how an outgrowth of ectoplasm is formed in a jerky way and the entire endoplasm quickly pours into it with a swirl. Then a new pseudopod is formed, and again a rapid transfusion of the contents of the amoeba follows. Sometimes the amoeba seems to freeze for a few moments, and then suddenly begins its characteristic movement again. A large vegetative form is found in the freshly excreted liquid feces of a patient with acute amoebiasis, which undoubtedly confirms the diagnosis.

Tissue form of amoeba.

Translucent form of amoeba.

The luminal form of the amoeba lives in the lumen of the upper sections of the large intestine and is the main form of existence of the dysenteric amoeba. Translucent forms can be found in liquid freshly excreted feces of convalescents or patients with chronic amoebic dysentery. It does not occur in carriers or patients in remission in a formed or semi-formed stool. For detection, it is necessary to examine feces obtained by deep bowel lavages, or the last portions of feces after taking a saline laxative. The size of the amoeba is 15 - 20 microns. In the native preparation, the amoeba nucleus is not visible. The cytoplasm contains bacteria, small vacuoles, but does not contain erythrocytes. The movement is weaker than that of the tissue form, pseudopods are formed more slowly, their size is also smaller. The division into ecto- and endoplasm is expressed only during the formation of prolegs.

Precistic formamoeba .

The precystic form of the amoeba is usually found in semiformed stools. The size of the amoeba is 12 - 20 microns. The structure resembles a translucent form.

Life cycle of the dysenteric amoeba.

The translucent forms of the dysenteric amoeba live in the upper part of the human large intestine without harming it. However, under certain conditions, turning into pathogenic tissue forms, they penetrate the intestinal wall.
Translucent forms, passively moving along with the contents of the intestine, enter its terminal sections, where unfavorable conditions (dehydration, changes in the bacterial flora, changes in the pH of the medium, etc.) lead to the death of amoebae or their transformation into cysts. Cysts with human feces are released into the environment, where they can persist for a long time. For humans, mature quadruple cysts are contagious.
Cysts, getting into the water, vegetables, hands and food (on which they are brought, in particular, by flies), various objects, such as dishes, toys, are eventually brought into the human mouth. From here they penetrate into the gastrointestinal tract, where their shell dissolves. Each nucleus divides in two, an eight-nuclear amoeba is formed, from which 8 daughter ones arise.

Clinical picture dysenteric amoeba.

Dysenteric, or histological, amoeba causes amoebic dysentery, or amoebiasis, in humans. Multiple ulcers form in the large intestine. The disease is of varying severity and begins acutely or gradually. Pain in the lower abdomen, frequent liquid stools of red-brown color due to the admixture of blood and mucus (stools often resemble meat slops) are disturbing. Body temperature is usually normal. The disease can last with periodic exacerbations for several years. In severe cases, anemia and malnutrition develop.
The tissue form of amoeba from intestinal ulcers can be carried with blood to the liver, lungs, brain and other organs, causing abscesses there. These complications can be fatal if left untreated.

Diagnosis.

To identify dysenteric amoebae or their cysts, feces are examined. For this purpose, native smears of feces are prepared on glass slides in a drop of isotonic sodium chloride solution and a drop of Lugol's solution.
In a native smear (X400), mobile vegetative forms are observed. Cysts are clearly visible in Lugol's solution. In difficult cases, the preparations are stained according to Heidenhain.
For research, you need to take freshly excreted feces, since amoeba quickly, within 10-20 minutes, lose their mobility, which makes reliable diagnosis impossible. Amoeba cysts can also be found in the formed feces, even if it is stored for several hours before the study. If only luminal forms or cysts are detected, then amoebic dysentery cannot be diagnosed, since they can only be a sign of carriage. Therefore, with clinical indications, i.e., suspicion of the possibility of amoebiasis, multiple studies are carried out, a saline laxative is prescribed, because large vegetative or tissue forms can only be found in liquid or semi-liquid feces. At the same time, pathological impurities (lumps of mucus) are examined first of all.
It should be borne in mind that in the acute stage of the disease with feces, only tissue, or rather, large vegetative forms, are more often isolated, and in the recovery period, translucent forms and cysts.
If it is impossible to immediately examine the feces, their preservation is allowed. The preserved material can be studied in a few days or sent for a consultation. The protozoa in the preservative stain and lose their mobility, which to a certain extent complicates laboratory research.
If an amoebic abscess is suspected, the contents obtained during surgery or puncture are microscopically examined. In this case, amoebae are more often found in the material taken at the border of healthy and diseased tissues, on the inner surface of the abscess capsule, than directly in the pus. Previous antibiotic or chemotherapy may cause a negative result of such a study. Methods for the serological diagnosis of amoebiasis (RHA, RIF, REMA) have been developed.

Prevention.

The distribution and transmission mechanism of amoebic and bacterial dysentery have much in common, so preventive measures are also similar. Patients are hospitalized. An extract is allowed after receiving 3 negative stool tests conducted within 1 week. In case of unstable stool in convalescents, as well as if it is necessary to identify carriers among healthy individuals, at least 6 tests are performed within 2 weeks.
After discharge, patients who have been ill are subject to observation in the offices of infectious diseases of polyclinics for at least a year with periodic examination of feces. The carriers are being sanitized.
Feces, contaminated linen are neutralized with a 3% solution of lysol. Normal water chlorination does not affect cysts. Quick effect gives only boiling.
Carriage of dysenteric amoeba is recorded everywhere, however, diseases are observed most often in Central Asia, the Caucasus and the Far East. Imported cases are possible.

abstract

Subject: Amoeba

Completed by: 1st year student Davletkulova A.R.

Checked by: Satarov V.N.

Ufa-2012

2.structure and life of the amoeba

3.dysentery amoeba

Amoeba

In addition to pseudopodia, due to which the body of the amoeba does not have a definite shape, these organisms are characterized by the absence of a rigid cell membrane. The cell is surrounded only by a special molecular layer, the plasma membrane - an integral part of the living cytoplasm. The latter is subdivided into a thin superficial relatively homogeneous part, called ectoplasm, and a granular endoplasm lying in depth. That, in turn, consists of an outer gelatinous zone, plasmagel, and an internal fluid plasmazole. The endoplasm contains the nucleus, as well as digestive and contractile vacuoles. Food captured by pseudopodia, such as bacteria, algae and protozoa, is surrounded by a digestive vacuole and digested in it. Undigested material is ejected from the cell when the membrane of this vacuole fuses with the plasma membrane. Metabolic waste products are released to the outside by simple diffusion. A certain part of them may be removed through contractile vacuoles, but the main function of the latter is to remove excess water from the cell. They contract from time to time, pushing it outward. Reproduction in amoebas is asexual - by cell division in two. At the same time, the nucleus divides mitotically, and then the cytoplasm is drawn and splits into two parts, approximately equal in volume, containing each daughter nucleus. The two cells formed grow and eventually divide as well.

The structure and activity of the amoeba

This gelatinous unicellular creature is so small that it can only be seen under a microscope. The main amoeba species live in freshwater rivers and ponds. But there are species that live at the bottom of salty reservoirs, in moist soil and food. The amoeba is constantly changing its shape. She moves, pushing forward first one of her half, then the other. Like many jelly-like organisms, the amoeba moves in such a way that it forms a shape called a “false leg,” or pseudopodia. When the pseudopodia reaches the food, it envelops it and takes it into the main body. This is how the amoeba eats. She doesn't have a mouth. Amoeba belongs to the class of protozoa, which are the lowest rank of living beings. She has neither lungs nor gills. But it sucks in oxygen from the water, releases carbon dioxide, digests food, as more complex animals do. Probably, the amoeba also has feelings. When touched or when aroused, she immediately curls up into a tiny ball. Amoeba avoids bright light, too hot or cold water. In an adult amoeba, the nucleus, a tiny dot in the center of the protoplasm, divides into two parts. After that, the amoeba itself bifurcates, forming new independent organisms. When they reach full size, they begin to divide again. In their structure, the protozoa are extremely diverse. The smallest ones are 2-4 microns in diameter (a micrometer is 0.001 mm). Their most common sizes are in the range of 50-150 microns, some reach 1.5 mm and are visible with the naked eye.

The amoeba has the simplest structure. The body of the amoeba is a lump of semi-liquid cytoplasm with a nucleus in the middle. The entire cytoplasm is divided into two layers: the outer, viscous - ectoplasm and the inner, much more liquid - endoplasm. These two layers are not sharply demarcated and can turn into each other. The amoeba does not have a hard shell, and it is able to change the shape of the body. When an amoeba crawls over a leaf of an aquatic plant, protrusions of the cytoplasm are formed in it in the direction in which it moves. Gradually, the rest of the cytoplasm of the amoeba flows into them. Such protrusions are called pseudopodia or pseudopodia. With the help of pseudopodia, the amoeba not only moves, but also captures food. With pseudopodia, it covers a bacterium or microscopic algae, soon the prey is inside the body of the amoeba, and a bubble is formed around it - a digestive vacuole. Undigested food remains are thrown out after a while.

Amoeba proteus: 1 - core; 2 - digestive vacuoles; 3 - contractile vacuole; 4 - pseudopods; 5 - undigested food remnants thrown out.

In the cytoplasm of the amoeba, a light bubble is usually visible, which either appears or disappears. This is a contractile vacuole. It collects excess water that accumulates in the body, as well as the liquid waste products of the amoeba. The amoeba, like all other protozoa, breathes over the entire surface of the body.

Euglena green: 1 - flagellum; 2 - eye spot; 3 - contractile vacuole;

The most complex structure of the simplest ciliates. Unlike the amoeba, their body is covered with the thinnest shell and has a more or less constant shape. The support fibers that run in different directions also support and determine the shape of the body. However, the body of ciliates can quickly contract, change its shape, and then return to its original shape. The contraction is carried out with the help of special fibers, similar in many respects to the muscles of multicellular animals. Ciliates can move very quickly. So, a shoe in a second overcomes a distance exceeding the length of its body by 10-15 times. At the same time, many cilia that cover the entire body of the ciliate make fast rowing movements, up to 30 per second (at room temperature). In the ectoplasm of the shoe there are many trichocyst sticks. When irritated, they are thrown out, turning into long threads, and hit the enemy attacking the ciliate. Instead of those thrown out in the ectoplasm, new trichocysts are formed. On one side, approximately in the middle of the body, the shoe has a deep oral cavity leading to a small tubular pharynx.

Infusoria shoe: 1 - cilia; 2 - digestive vacuoles; 3 - large nucleus (macronucleus); (micronucleus); 5 - mouth opening and pharynx; 6 - undigested food residues thrown out; 7 - trichocysts; 8 - contractile vacuole.

Through the pharynx, food enters the endoplasm, where it is digested in the resulting digestive vacuole. In ciliates, unlike amoebas, undigested food residues are thrown out in a certain place in the body. Their contractile vacuole is more complex and consists of a central reservoir and conducting channels. The ciliates have two types of nuclei: large - macronucleus and small - micronucleus. Some ciliates may have several macro- and micronuclei. The macronucleus differs from the micronucleus in a significantly larger number of chromosomes. And therefore, it contains a lot of deoxyribonucleic acid (DNA), which is part of the chromosomes.

Different types of ciliates: 1 - ciliates trumpeter; 2-5 - planktonic ciliates.

Dysentery amoeba (Entamoeba histolytica), the simplest of the amoeba order; the causative agent of amoebic dysentery was first described in 1875 by the Russian scientist F.A. Lesh. At hit in intestines of the person D. and. in most cases, it multiplies in the contents of the colon, without penetrating into the tissues and without causing intestinal dysfunction (the person is healthy, but serves as a carrier of D. a.). This form D. and. called translucent (forma minuta) (size about 20 microns) (Fig. 1, a). It moves with the help of pseudopodia. The nucleus is spherical, 3-5 μm in diameter, chromatin is located under the nuclear envelope in the form of small clumps; in the center of the nucleus is a small karyosome. There may be several phagocytosed bacteria in the endoplasm. When feces thicken in the large intestine, the luminal form is surrounded by a membrane and turns into a spherical cyst (about 12 microns in size) with 4 nuclei that do not differ in structure from the nucleus of the vegetative form; immature cysts contain 1-2 or 3 nuclei. There is a vacuole with glycogen; some of the cysts contain short, barlike formations - chromatoid bodies (Fig. 1b). With faeces, cysts are released into the environment and can again enter the human gastrointestinal tract, where, after the metacystic stage of development (dividing into 8 daughter amoebae), they give rise to translucent forms (Fig. 2, A).

Protozoa in a drop of pond water (under a microscope).

Rhizome class unites the simplest unicellular animals, the body of which is devoid of a dense shell, and therefore does not have a permanent shape. They are characterized by the formation of pseudopods, which are temporarily formed outgrowths of the cytoplasm that promote movement and capture of food.

Habitat, structure and movement of the amoeba. The common amoeba is found in the silt at the bottom of the ponds with contaminated water. It looks like a small (0.2-0.5 mm), colorless gelatinous lump, barely visible to the naked eye, constantly changing its shape ("amoeba" means "changeable"). The details of the structure of the amoeba can only be examined under a microscope.

The body of the amoeba consists of a semi-liquid cytoplasm with a small vesicle enclosed inside it core. Amoeba consists of one cell, but this cell is a whole organism leading an independent existence.

Cytoplasm cells are in constant motion. If the current of the cytoplasm rushes to one point on the surface of the amoeba, a protrusion appears on its body in this place. It increases, becomes an outgrowth of the body - a pseudopod, the cytoplasm flows into it, and the amoeba moves in this way. Amoeba and other protozoa capable of forming pseudopods are classified as rhizopods. They got this name for the external resemblance of the pseudopods to the roots of plants.

Vital activity of Amoeba.

Nutrition. An amoeba can simultaneously form several pseudopods, and then they surround food - bacteria, algae, and other protozoa. Digestive juice is secreted from the cytoplasm surrounding the prey. A vesicle is formed - a digestive vacuole. Digestive juice dissolves some of the substances that make up food and digests them. As a result of digestion, nutrients are formed that seep from the vacuole into the cytoplasm and go to build the body of the amoeba. Undissolved residues are thrown out anywhere in the body of the amoeba.

Amoeba Breath. Amoeba breathes oxygen dissolved in water, which penetrates into its cytoplasm through the entire surface of the body. With the participation of oxygen, complex food substances of the cytoplasm are decomposed into simpler ones. In this case, the energy necessary for the life and activity of the body is released.

Release of harmful substances life activity and excess water. Harmful substances are removed from the body of the amoeba through the surface of its body, as well as through a special bubble - the contractile vacuole. The water surrounding the amoeba constantly penetrates into the cytoplasm, liquefying it. The excess of this water with harmful substances gradually fills the vacuole. From time to time the contents of the vacuole are thrown out. So, from the environment, food, water, oxygen enter the body of the amoeba. As a result of the life of the amoeba, they undergo changes. The digested food serves as material for building the body of the amoeba. The substances harmful to the amoeba are removed outside. There is a metabolism. Not only amoeba, but also all other living organisms cannot exist without metabolism both inside their body and with the environment.

Amoeba reproduction. The feeding of the amoeba leads to the growth of its body. The grown amoeba begins to reproduce. (? Probably due to exceeding a certain mass of her body.) Reproduction begins with a change in the nucleus. It is stretched, the transverse groove is divided into two halves, which diverge in different directions - two new nuclei are formed. The body of the amoeba is divided into two parts by a constriction. Each of them gets one nucleus. The cytoplasm between both parts is torn, and two new amoebas are formed. The contractile vacuole remains in one of them, while in the other it reappears. So the amoeba reproduces by dividing in two. During the day, division can be repeated several times.

Division (reproduction) of Amoeba.

Cyst. The amoeba feeds and reproduces throughout the summer. In autumn, when cold weather sets in, the amoeba stops eating, its body becomes rounded, a dense protective shell is released on its surface - a cyst is formed. The same thing happens when the pond dries up where amoebas live. In the state of a cyst, the amoeba endures unfavorable living conditions for it. When favorable conditions occur, the amoeba leaves the cyst shell. She releases pseudopods, begins to feed and multiply. Cysts carried by the wind contribute to the dispersal (spread) of amoebae.

Possible additional questions for self-study.

• What makes the Cytoplasm systematically flow from one part of the Amoeba to another, forcing it to move in a given direction?
• How does the membrane of the cytoplasm of Amoeba recognize nutrients, as a result of which the amoeba purposefully forms pseudopods and a digestive vacuole?

Animals, like all organisms, are at different levels of organization. One of them is cellular, and its typical representatives are the amoeba proteus. We will consider the features of its structure and life activity in more detail below.

Subkingdom Unicellular

Despite the fact that this systematic group unites the most primitive animals, its species diversity already reaches 70 species. On the one hand, these are indeed the most simply arranged representatives of the animal world. On the other hand, these are simply unique structures. Just imagine: one, sometimes microscopic, cell is capable of carrying out all vital processes: respiration, movement, reproduction. Amoeba Proteus (the photo shows its image under a light microscope) is a typical representative of the Protozoa subkingdom. Its dimensions barely reach 20 microns.

Amoeba proteus: a class of protozoa

The very species name of this animal testifies to the level of its organization, since proteus means "simple". But is this animal so primitive? Amoeba Proteus is a representative of a class of organisms that move with the help of non-permanent outgrowths of the cytoplasm. Colorless blood cells that form human immunity also move in a similar way. They are called leukocytes. Their characteristic movement is called amoeboid.

What environment does the amoeba proteus live in?

The proteus amoeba that lives in polluted water bodies does no harm to anyone. This habitat is the most suitable, since in it the protozoan takes its important role in the food chain.

Structural features

Amoeba Proteus is a representative of the class, or rather the sub-kingdom of Unicellular. Its size barely reaches 0.05 mm. With the naked eye, it can be seen in the form of a barely noticeable jelly-like lump. But all the main organelles of the cell will be visible only under a light microscope at high magnification.

The surface apparatus of the amoeba Proteus cell is represented by which has excellent elasticity. Inside is a semi-liquid content - the cytoplasm. She moves all the time, causing the formation of pseudopods. Amoeba is a eukaryotic animal. This means that its genetic material is contained in the nucleus.

Movement of protozoa

How does the amoeba proteus move? This occurs with the help of non-permanent outgrowths of the cytoplasm. She moves, forming a protrusion. And then the cytoplasm smoothly flows into the cell. The pseudopods retract and form elsewhere. For this reason, the amoeba proteus does not have a permanent body shape.

Nutrition

Amoeba Proteus is capable of phago- and pinocytosis. These are the processes of absorption by the cell of solid particles and liquids, respectively. It feeds on microscopic algae, bacteria and similar protozoa. Amoeba proteus (the photo below shows the process of capturing food) surrounds them with its pseudopods. Next, the food is inside the cell. A digestive vacuole begins to form around it. Thanks to digestive enzymes, particles are broken down, absorbed by the body, and undigested residues are removed through the membrane. By phagocytosis, blood leukocytes destroy pathogenic particles that penetrate the human and animal body every moment. If these cells did not protect organisms in this way, life would be almost impossible.

In addition to specialized nutritional organelles, inclusions can also be found in the cytoplasm. These are non-permanent cellular structures. They accumulate in the cytoplasm when there are necessary conditions for this. And they are spent when there is a vital need for it. These are grains of starch and droplets of lipids.

Breath

Amoeba Proteus, like all unicellular organisms, does not have specialized organelles for the respiration process. It uses oxygen dissolved in water or other liquid, when it comes to amoebas that live in other organisms. Gas exchange occurs through the surface apparatus of the amoeba. The cell membrane is permeable to oxygen and carbon dioxide.

reproduction

Amoeba is characterized by cell division in two. This process is carried out only in the warm season. It takes place in several stages. First, the nucleus is divided. It is stretched, separated by constriction. As a result, two identical nuclei are formed from one nucleus. The cytoplasm between them is torn apart. Its sections separate around the nuclei, forming two new cells. appears in one of them, and in the other, its formation occurs anew. Division occurs by mitosis, so the daughter cells are an exact copy of the parent. The process of amoeba reproduction occurs quite intensively: several times a day. So the life expectancy of each individual is quite small.

Pressure regulation

Most amoebas live in the aquatic environment. A certain amount of salts is dissolved in it. Much less of this substance in the cytoplasm of the simplest. Therefore, water must flow from the area with a higher concentration of the substance to the opposite one. These are the laws of physics. In this case, the body of the amoeba would have to burst from an excess of moisture. But this does not happen due to the action of specialized contractile vacuoles. They remove excess water with salts dissolved in it. At the same time, they provide homeostasis - maintaining the constancy of the internal environment of the body.

What is a cyst

Amoeba Proteus, like other protozoa, has adapted in a special way to the experience of adverse conditions. Her cell stops eating, the intensity of all vital processes decreases, the metabolism stops. The amoeba stops dividing. It is covered with a dense shell and in this form endures an unfavorable period of any duration. This happens periodically every autumn, and with the onset of heat, a unicellular organism begins to intensively breathe, feed and multiply. The same can happen in the warm season with the onset of drought. The formation of cysts has another meaning. It lies in the fact that in this state, the amoeba carries the wind over considerable distances, settling this biological species.

Irritability

Of course, these simplest unicellular organisms are not talking about the nervous system, because their body consists of only one cell. However, this property of all living organisms in the amoeba Proteus manifests itself in the form of taxis. This term means a response to the action of stimuli of various kinds. They may be positive. For example, an amoeba clearly moves towards food objects. This phenomenon, in fact, can be compared with the reflexes of animals. Examples of negative taxis are the movement of the amoeba proteus from bright light, from an area of ​​​​high salinity or mechanical stimuli. This ability is primarily defensive.

So, the amoeba proteus is a typical representative of the sub-kingdom Protozoa or Unicellular. This group of animals is the most primitively arranged. Their body, however, it is able to perform the functions of the whole organism: breathe, eat, multiply, move, respond to irritations and adverse environmental conditions. Amoeba proteus is part of the ecosystems of fresh and salt water bodies, but is able to live in other organisms. In nature, it is a participant in the circulation of substances and the most important link in the food chain, being the basis of plankton in many water bodies.