The overall characteristic of single-celled (simplest). Brief description of the fault The simplest overall characteristics of single-celled animals briefly
Animals consisting of a single cell with a nucleus are called single-cell organisms.
They combine the characteristic features of the cell and an independent organism.
Unicellular animals
Animals of the facilities of unicellular or protozoa dwell in liquid media. The external forms of them are diverse - from amorphous individuals that do not have certain outlines, to representatives with complex geometric forms.
There are about 40 thousand species of unicellular animals. The most famous belongs:
- amoeba;
- green Evglen;
- infusorian-shill.
Amoeba
Belongs to the Cartoon Class and is distinguished by a non-permanent form.
It consists of a shell, cytoplasm, a contractile vacuole and kernel.
The absorption of nutrients is carried out using a digestive vacuole, and the feed serve other simplest, such as algae and. To respond, Amebe requires oxygen dissolved in water and penetrating the surface of the body.
Green Evglen
It has an elongated fan-shaped form. It feeds through the conversion of carbon dioxide and water into oxygen and food due to light energy, as well as ready-made organic substances in the absence of light.
Refers to the class of flagella.
Infusorian-shoe
The class of infusoria, its outlines resembles a shill.
Food serve bacteria.
Unicellular mushrooms
Mushrooms are attributed to the lower inhlormophilic eukaryotes. They differ in the outer digestion and chitin content in the cell wall. The body forms a fungouncing consisting of gifs.
Unicellular mushrooms are systematized in 4 major classes:
- deuteromycetes;
- chitridomycetes;
- sigomycetes;
- ascomycetes.
A bright example of ascomyttes serve yeast, widespread in nature. The speed of their growth and reproduction is large due to the special structure. Yeasts consist of a single cell of the rounded shape, multiplying the kill.
Unicellular plants
A typical representative of the lower single-cell plants, often found in nature, are algae:
- chlammedonada;
- chlorella;
- spirohyra;
- chlorococcus;
- volvoks.
Chlammedonad differs from all algae mobility and the presence of a photosensitive eye that determines the places of the greatest cluster of solar energy for photosynthesis.
Numerous chloroplasts are replaced with one large chromatophore. The role of pumps, pumping fluid surplus, perform contractile vacuoles. Movement is carried out with two flagella.
Green algae chlorella, in contrast to chlammedonads, possess typical vegetable cells. The dense shell protects the membrane, and in the cytoplasm there is a kernel and chromatophore. The functions of the chromatofor are similar to the role of chloroplast ground plants.
With chlorella, the algae of a spherical shape of chlorococcus. Its habitat is not only water, but also sushi, trunks of trees growing in a humid environment.
Who opened single-cell organisms
The honor of the opening of microorganisms belongs to the Dutch scientist A. Levenguka.
In 1675, he saw them in a microscope of his own manufacture. For the smallest creatures, the name of the infusorium was entrenched, and since 1820 they began to call them the simplest animals.
Zologners Kellekher and Zibold in 1845, unicellites were attributed to the special type of animal kingdom and divided into two groups:
- root;
- infusoria.
What does a cell of a single-cell animal look like
The structure of single-cell organisms can be studied only with the help of a microscope. The body of the simplest creatures consists of a single cell that performs the role of an independent organism.
The cell includes:
- cytoplasm;
- organoids;
- nucleus.
Over time, as a result of adaptation to the environment, special types of unicelligers appeared special organoids of movement, release and nutrition.
Who are the simplest
Modern biology relates the simplest to the paraffilic group of animal-like protists. The presence in the coder cell, in contrast to the bacteria, includes them in the list of eukaryotes.
Cellular structures differ with multicellular cells. In the living system of simplest, digestive and contractile vacuoles are present, in some observed with the oral cavity and anal hole of the organelles.
Classes of simplest
In a modern classification, there is no separate rank and the value of unicellular.
Labyrinatula
They are customary to divide into the following types:
- sarcomavigodors;
- apicpleks;
- mixporidity;
- infusoria;
- labyrinatules;
- ascerpportion.
An outdated classification is considered to divide the simplest on flagella, sarkodic, ciliation and disputes.
In which environments inhabit the unicellular
The habitat of the simplest unicellites is any wet environment. Amoeba ordinary, Evglen green and infusorian-shill are typical inhabitants of contaminated fresh water sources.
Science has long delivered fallen to infusories, thanks to the external similarity of flavors with the cilia and the presence of two nuclei. As a result of careful research, the relationship was refuted. The sexual reproduction of opalines occurs as a result of copulation, the kernel is the same, and there is no eyelash.
Conclusion
The biological system is impossible to submit without single-cell organisms that are the source of other animals.
The simplest organisms contribute to the formation of rocks, serve as indicators of water pollution, are involved in carbon cycle. Wide use of microorganisms found in biotechnology.
For the first time, unicellites were opened by the human eye in the 1670s, thanks to the Dutch Naturalist, endowed with a huge passion for the knowledge of the world, Anthony Wang Levenguka. It was he who first examined these "small animals" with the help of their incredible lenses. Their scientific learning began later - and does not stop so far. Unicellites live everywhere, including in such conditions where other organisms do not survive.
What distinguishing features are inherent in unicellular?
1. Morphologically unicellular are single cage. However, according to its functions - this is self-sufficient organismWho knows how to move in space, multiply, eat. Single-cell sizes range from several microns to several centimeters. A few years ago, multi-core xenophylamores with a diameter of at least 10 centimeters were discovered in the Mariana Wpadin.
2. Liquid medium - The principal condition for the existence of unicellular. And this is not only a sea or swamp, but also fluid inside the human body or other creatures.
3. Single-celled space of space and attract food with a closer look falselookee (temporary, ever-changing form of ectoplasm growth, like amoeba), zhgutikov (thin, long organelles, the threads of the cytoplasm, located in the front of the body, like Evglen green) and cisser (multiple increases of cytoplasm throughout the body, like infusoria). The flagellas are screwed into the liquid, as if corkscrew, and the cilia "clap", creating a wave movement.
4. Most unicellular - heterotrophs., that is, they feed on ready-made organic substances. Evglen Green - mixotrof, but the colonial volvox - avtotrof.
5. Irritability (cell's ability to change physicochemical properties under the influence of environmental conditions), one of the basic properties of a living organism, the simplest manifests taxis: Reactions to any irritation. Unicellites are moving either in the direction of the stimulus (for example, a fragment of food), or away from it.
6. Reflexes Unicellites do not have due to the lack of the nervous system.
8. With a bunch of reproduction of the simplest, unlike multicellular, does not destroy nuclear shell During cell division.
9. Of course, the simplest mitochondria.
The value of unicellular animals
1. The simplest is used in food larger invertebrates.
2. The external and internal skeletons of the shells of the AmeB, Foraminifera, radiolearies and other similar creatures for hundreds of thousands of years have formed marine sedimentary rocks that a person is used in construction (for example, a seven).
For single-cell, or simplest animals, the body of which morphologically corresponds to one cell, while being with the independent holistic organism with all the inherent functions. The total number of types of simplest exceeds 30 thousand.
Appearance Unicellular animals were accompanied by aromorphosis: 1. Diploidity (double chromosoma set) appeared in a core-bounded core as a structure separating the cells of the cytoplasm cell and creating a specific medium to interact in the diploid chromosome set. 2. An organides that are capable of self-reproduction occurred. 3. Internal membranes were formed. 4. A highly specialized and dynamic internal skeleton appeared - cytoskeleton. b. A sexual process arose as a form of sharing genetic information between two individuals.
Structure. The plan of the structure of the simplest corresponds to the general features of the organization of the eukaryotic cell.
Genetic alpathic Unicellites is represented by one or more nuclei. If there are two cores, then, as a rule, one of them, diploid, is a generative, and the other, polyploid, is vegetative. The generative kernel performs functions related to reproduction. Vegetative kernel provides all the processes of the body's life activity.
Cytoplasm Consideration of light source, devoid of organoids, - extoplasma and the darker inner part containing the main organides - endoplasm.In the endoplasm there are general applications.
Unlike the cells of the multicellular organism, unicellites have special purpose organo. These are organides of motion - falconed - pseudopod; flagella, cilia. There are organo-osmoregulation organides - contractile vacuoles. There are specialized organs providing irritability.
Unicellular with a permanent form of body have permanent digestive organoids: cell funnel, cellular mouth, throat, as well as organoid selection of undigested residues - poroshires.
INunfavorable The conditions of the existence of a core with a small amount of cytoplasm containing the necessary organides are surrounded by a thick multi-layer capsule - a cystic and transitions from the active state to the rest. If you get into favorable conditions, the cysts are "revealed", and the simplest in the form of active and moving individuals.
Reproduction. The main form of reproduction "of the simplest - the most powerful reproduction by mitotic division of the cell. However, the sexual process is often found.
Sarcodic class. or root.
Amoeba
The class includes a detachment of amoeba. A characteristic feature is the ability to form cytoplasmic grown - pseudopodia (falsecakes), thanks to which they move.
Amoeba:1 - core, 2 - cytoplasm, 3 - pseudopodia, 4 - contracting vacuole, 5 - formed digestive vacuol
Structure. Body shape is inconsistent. The hereditary apparatus is represented by one, as a rule, polyploid core. The cytoplasm has a distinct unit on an ecoto and endoplasm, in which general purpose organides are located. Free-lived freshwater forms have simply arranged contracting vacuol.
Method of nutrition. All feeding feeds by phagocytosis, capturing food with false peasants.
Reproduction. For the most primitive representatives of the groups of the AmeB and the shell, AmeB are characterized by only the useless reproduction by mitotic cell division.
Class of badge
Structure. The flagellas have flagellas who serve as organoids of movement and contributing to the seizure of food. There may be one, two or many. The movement of the burning burning in the surrounding water is caused by a whirlpool, thanks to which small particles weighted in water are keen on the base of the flavor, where there is a small hole - a cell mouth leading to a deep-sided channel.
Evglen green:1 - Zhgutichka, 2 - contractile vacuole, 3 - chloroplasts, 4 - core, 5 - contracting vacuol
Almost all flagellas are covered with a dense elastic shell, which, along with the developed elements of the cytoskeleton, determines the constant body shape.
Genetic apparatus Most of the flagellas are represented by one core, but there are also duid (for example, giardia) and multi-core (for example, opalin).
Cytoplasm It is clearly divided into a thin outer layer - a transparent ectoplasm and a deeper endoplasm.
Method of nutrition. By the method of nutrition, flagellas are divided into three groups. Avtotrophny Organisms as an exception in the kingdom of animals synthesize organic substances (carbohydrates) from carbon dioxide and water with chlorophyll and solar radiation energy. Chlorophyll is located in chromatophoras similar to the organization with plants plates. Many flagendrians with vegetable food type have special devices that perceive light irritation - stigma.
Heterotrophic Organisms (tribanosoma - the causative agent of the sleepy disease) do not have chlorophyll and therefore cannot be synthesized carbohydrates from inorganic substances. Mixotrophic Organisms are capable of photosynthesis, but also feed on mineral and organic substances created by other organisms (green eurlen).
Osicore regulatory and Partly excretory functions are performed in flagella, like sarcodic, contractile vacuoles, which are available at free-lived freshwater forms.
Reproduction. The flagellas have sexual and powerful reproduction. The usual shape of the crucible reproduction is a longitudinal division.
Infusoria type, or wilderness
General characteristics. TO The type of infusories includes more than 7 thousand species. Equipment of motion serve cilia. There are two cores: large polyploid - vegetative kernel (macronucleus) and petty diploid - generative kernel (Micronuclease).
Structure. Infusoria can be a variety of shape, in most commonly oval, as a shower infusorium. They are achieved in length 1mm . Outside the body is covered with pellicula. Cytoplasm It is always clearly divided into ecto- and entoderm. In the ectoplasma there are basal cilia tales. Elements of the cytoskeleton are closely connected with basal bodies.
Method of feeding infusoria. IN The front half of the body is a longitudinal excavation - Okamot Vpadina. In the depths of it, an oval hole is a cellular mouth leading to a curved throat, which is supported by a skeletal piping yard system. The throat is opened directly in the endoplasm.
Osorgulatory. Free-lived infusorium-mixed vacuoles.
Infusorian shoe:1 - Cilia, 2 - digestive vacuoles, 3 - small kernel, 4 - large kernel, 5 - cellular, in - cell pharynx, 7 - Poroshitz, 8 - contractive vacuol<
Reproduction. For infusories, the alternation of sexual and powerful reproduction is characteristic. With a bunch of reproduction, the transverse division of infusories takes place.
Habitat. Free-lived infusories are found in fresh waters, and in the seas. A few of them are diverse.
Unicellular or simple organisms called those organisms whose bodies are one cell. It is this cell that carries out all the necessary functions for the life of the body: moving, food, breathing, reproduction and removal of unnecessary substances from the body.
Arbitration of simplest
The simplest performing cell functions, and a separate organism simultaneously. There are about 70 thousand species of this fabrication in the world, most of them are organisms of microscopic size.
2-4 microns are the size of small protozoa, and the usual reaches 20-50 microns; For this reason, it is impossible to see them with a naked eye. But there are, for example, 3 mm long infusories.
It is possible to meet representatives of the simplicity of the simplest in the liquid medium: in the seas and water bodies, in swamps and wet soils.
What are the unicellular?
There are three types of single-celled: sarcoma interns, disputes and infusories. A type sarcomavigor Includes sarcodic and flagella, and type infusoria - Rishichny and sucking.
Features of the structure
A feature of the structure of unicellites is the presence of structures that are characteristic of exceptionally simple. For example, cell mouth, contractile vacuole, poroshiret and cell pharynx.
For the simplest, the separation of the cytoplasm is characterized by two layers: internal and external, which is called ectoplasm. The structure of the inner layer is included in the organelles and the endoplasm (kernel).
To protect there is a pellicula - a layer of cytoplasm, characterized by a seal, and mobility and some nutritional functions provide organelles. Between endoplasm and ectoplasma there are vacuoles that regulate the water-salt balance in the unicellular one.
Single-cell food
The simplest possible two types of food are possible: heterotrophic and mixed. There are three ways to absorb food.
Phagocytosis Call the process of capturing solid food particles using cytoplasm growths, which have the simplest, as well as other specialized cells in multicellular. AND Pinocytosis represented by the process of seizing fluid itself by the cell surface itself.
Breath
Selection The simplest is carried out using diffusion or via contractile vacuoles.
Reproduction of simplest
There are two methods of reproduction: sexual and cull. Paveless represented by mitosis, during which the core is divided, and then cytoplasm.
AND paul The reproduction occurs with the help of isogami, oogami and anisogamy. For the simplest characteristic alternation of sexual reproduction and one-time or multiple cullless.
Type of simplest
Sarcomavigods
Sarkodova
Ameb of protea (ordinary), amoeba dysenteric, radolar
Zhgutikova
Evglen Green, Volvoks, Tripanosoma African, Leinsmania, Trichomonada, Giardia Hepatic
Spores
Cocidian-shaped
Malari plasma
Infusoria
Rishichny
Infusor-Balantidium, Infusorian-Tofflower, Trumpeter Infusoria
Trichofriosis
Used Books:
1. Kiology: a full guide to prepare for the exam. / I.Lerner. - M.: AST: Astrel; Vladimir; VKT, 2009 2. Kiology: Animals: studies. for 7-8 cl. general education. Institutions. - 7th ed. - M.: Enlightenment, 2000. 3.Biology: studies. - Celebration / A.G. Lebedev. M.: Ast: Astrel. 2009. 4. Biology. Full course of secondary secondary school: a textbook for schoolchildren and applicants / M.A.Vova, N.A.Sokolova, A.A. Kamensky. - M.: Exam, 2002. 5. Biology for entering universities. Intensive course / G.L.Bilich, V.A. Kryzhanovsky. - M.: Publishing House Onix, 2006.
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