unicellular organisms - These are organisms that consist of only one cell, in which all the necessary vital functions inherent in multicellular organisms are carried out. These organisms are found among prokaryotes (bacteria, cyanobacteria, archaebacteria) and among the major kingdoms of eukaryotes. There are unicellular animals (for example, amoeba proteus, green euglena, ciliate shoe), unicellular plants (for example, green algae chlamydomonas and chlorella, diatoms), unicellular fungi (mucor, yeast). Unicellular organisms, as a rule, are small in size, that is, microorganisms. However, some unicellular animals are visible to the naked eye, and some multicellular organisms microscopic. The first organisms on Earth were single-celled, but the rich clitinism independently developed several times in the process of evolution. Cells of unicellular organisms combine the properties of both cells and an independent organism. Therefore, they are larger than the cells of multicellular organisms.
colonial organisms- These are organisms consisting of many cells of one or more types, functioning independently of each other. Colonial organisms include colonial flagellates (for example, volvox, eudorina), colonial ciliates (zootamnia), colonial coelenterates (siphonophora, coral polyps), etc. more or less complex combination - a colony. In plant flagellates (evdorina, gonium), the cells of the colony are combined with each other with jelly. And in a Volvox colony, individual cells are not completely isolated from each other, but are interconnected by thin cytoplasmic bridges. In other, more complexly organized colonies, individuals may occupy a certain place and perform special functions that are important for the entire colony. For example, in siphonophores, each colony consists of mutated polyps and jellyfish that are morphologically and functionally specialized. Mutual integration and specialization, at the same time, reaches such a depth that the colony acquires the features of a single organism.
Multicellular organisms- these are organisms consisting of a set of cells, groups of which specialize in performing certain functions, creating qualitatively new structures: tissues, organs, organ systems. In most cases, due to this specialization, individual cells cannot exist outside the body. Multicellular organisms are most plants, fungi and animals. Since cells, tissues, organs, and organ systems are involved in the implementation of a certain vital function, this function in multicellular organisms will have a more complex and perfect character. The specialization of the constituent parts of a multicellular organism to perform a certain function makes them dependent on other parts, therefore, along with differentiation, integration processes take place, due to which internal connections are formed between the parts (physiological, genetic, nervous, humoral, etc.), which determine the subordination of their body as complete system. Multicellular organisms combine the molecular, cellular, tissue, organ and system levels.
Textile- a collection of cells that are similar in structure, origin and functions. Tissues are formed in multicellular organisms due to cell differentiation. Cell differentiation - the process of occurrence of differences in the structure and functions of cells during their development. The main factors of cell differentiation are: a) differences in the cytoplasm of early embryonic cells, which are due to the heterogeneity of the cytoplasm of the egg; b) induced influences of neighboring cells; c) the influence of hormones; d) the influence of environmental factors, etc. This important process is carried out mainly in the process of embryonic development and in some organs of the adult organism (for example, in the hematopoietic organs, gonads). Cell differentiation is usually irreversible.
The molecular genetic basis of cell differentiation is the activity of genes specific for each tissue. Tissues arise in most multicellular animals and higher plants; lower plants and fungi do not have tissues.
Comparative characteristics of plant and animal tissues
Organs A part of an animal or plant organism that performs one or more functions. Organs are made up of tissues various types, but, as a rule, one of them predominates (for example, in the heart, transversely smeared cardiac tissue predominates). These structures of multicellular organisms are characterized by location, structural features, functions performed, and the like. Organs, performing joint functions, form an organ system. Within systems, organs can be sequentially connected to each other (eg, organs of the digestive tract) or "scattered" in the body (eg, organs of the endocrine system). All organs of the body are interconnected and interact - correlate. Correlation is a measure of the dependence of two or more random variables. In this case, a change in one or more of these quantities leads to a systematic change in another or other quantities. In the process of evolution, organs, in connection with the performance of additional functions, can be modified (for example, modifications of the shoot are antennae, whiskers, spines, tubers, bulbs, rhizomes, etc.).
variety of organs
BUT. By function
B. If there is a cavity: parenchymal - filled with binder or underlying tissues (e.g. lungs, leaflet) empty- have a cavity inside (for example, a stomach, a stalk of cereals).
AT. Longevity: postyni- function for the rest of life (eg, brain, stem) temporary - exist for a short time, and then disappear (for example, placenta, flower).
G. By location: external(e.g. eyes, leaf) and internal(e.g. heart, germ).
D. Origin: homologous - have the same origin but perform different functions (e.g. tiger paw and seal flippers, potato tubers and hawthorn thorns) similar - have different origins, but perform similar functions (for example, butterfly wing and bird wing, hawthorn spines and cactus spines).
In the process of development in the body of plants and animals, organs functionally complement each other, forming physiological and functional systems. Physiological systems of organs - this is a constant combination of organs that perform common vital physiological processes in the body (for example, the respiratory system to perform the function of breathing). In the body of multicellular animals and humans, the following main physiological systems of organs are conditionally distinguished, such as circulatory, respiratory, digestive, urinary, reproductive, nervous, etc. Functional organ systems - this is a temporary combination of organs of various systems to perform certain functions. For example, during the running of animals, the organs of the respiratory, circulatory, musculoskeletal, and nervous systems function in concert.
Colonial living organisms are made up of identical cells living together (corals) The colonial organism term that combines two groups of organisms:
1. Organisms consisting of a small number of cells, poorly differentiated and not divided into tissues; in many cases, such a cell retains the ability to reproduce (volvox green algae pandorina, Eudorine and others, many types of suviyoka and other groups resist).
2. Multicellular organisms that form colonies of several individuals, more or less closely related to each other, which usually have the same genotype and common metabolism and regulatory systems.
Colonial organisms that, during asexual (vegetative) reproduction, remain connected with the daughter and subsequent generations, forming a more or less complex association - a colony. Colonial plants include various unicellular algae: blue-green, green, golden, yellow-green, diatoms, pyrophytes, euglenovi. According to the method of formation of colonies, they are divided into Zoospores and motorsport (reproduce by zoospores or motorsport). Colonial animals include mainly marine animals - invertebrates and lower chordates. Of the unicellular - some flagellates, radiolarians, ciliates; of other invertebrates there are many sponges, most of the intestinal cavities, including siphonophores, almost all hydroids, many coral polyps and polypoid generations of some scyphoids, bryozoans. Of the lower chordates - salps and doliolids (Doliolida). This also includes extinct graptolites. Some colonial animals (bryozoans, hydroids, coral polyps, synascidia, etc.) lead an attached lifestyle; the colony is usually immobile on the substrate and has a more or less developed skeleton. Colonial radiolarians, siphonophores, pyrosomes, caskers, and salps live in the water column. Usually they are translucent, their skeleton is not developed. Many are characterized by metagenesis: colonial generation, vegetatively reproduces, alternating with a single, sexual one. Colonial organisms played the role of an intermediate link in the process of the emergence of multicellular animals from unicellular ones.
Colonial organisms consist of a certain number of cells of one or more types. However, unlike multicellular organisms, colonial cells usually function independently.
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" xml:lang="-none-" lang="-none-">PAGE 18
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" xml:lang="en-EN" lang="en-EN">Plan
- " xml:lang="en-EN" lang="en-EN">Introduction.
- " xml:lang="en-EN" lang="en-EN">Distinctive features of colonial unicellular organisms.
" xml:lang="en-EN" lang="en-EN"> 3. Description of some unicellular colonial
" xml:lang="en-EN" lang="en-EN"> Organisms.
" xml:lang="en-EN" lang="en-EN"> 4." xml:lang="en-EN" lang="en-EN">" xml:lang="en-EN" lang="en-EN">
" xml:lang="en-EN" lang="en-EN">
" xml:lang="en-EN" lang="en-EN"> Most of the living organisms that inhabit our planet have a cellular structure, and their individual development begins from a single cell. Therefore, a cell is the basic unit of the structure and development of all existing now plant and animal organisms.The cell theory was formulated in 1838-1839 by the botanist Matthias Schleiden and the zoologist Theodor Schwann.These scientists proved the fundamental similarity between animal and plant cells, and on the basis of all the knowledge accumulated by that time postulated that the cell is a structural and functional unit of all living organisms.1855 Rudolf Virchow supplemented the cell theory with the statement of the Latin "Omnis cellula ex cellula" - "Each cell is from a cell."" xml:lang="en-EN" lang="en-EN">The basis of the cell theory: the cell is the main structural unit of the theory and the unit of development of living organisms" xml:lang="en-EN" lang="en-EN">;" xml:lang="en-EN" lang="en-EN">the nucleus is the main component of the cell; cells reproduce only by division; all cells have a membrane structure; cellular structure is evidence of the common origin of the plant and animal world." xml:lang="en-EN" lang="en-EN"> Cell theory is one of the fundamental ideas of modern biology, it has become an indisputable proof of the unity of all living things and the foundation for the development of such disciplines as embryology, histology and physiology.
" xml:lang="en-EN" lang="en-EN"> Over the 3 billion years of existence on Earth, living matter has evolved to several million species, but all of them - from bacteria to higher animals - consist of cells. As you know , a cell is the basic structural and functional unit of all living organisms, an elementary biological system. cellular level organization of living matter, all the basic properties of living matter are fully manifested: metabolism and energy transformations, the ability to grow and reproduce, movements, storage and transmission of hereditary information, etc. All cells of living organisms are divided into two types, taking into account their structure and functions in living organisms: prokaryotes (Latin pro - before and Greek karyon - nucleus), or prenuclear cells, and eukaryotes (Greek ey - completely, well and karyon - core). Organism (from lat. organism - I arrange, I give a slender appearance) is a biological system consisting of interconnected parts that function as a whole. Organisms living on Earth are very diverse in structure: unicellular, colonial and multicellular. Moreover, only among unicellular organisms there are prokaryotes, and all colonial and multicellular organisms are eukaryotes. For any organism, all the signs of a living thing are characteristic: metabolism and energy conversion, irritability, heredity and variability, growth, development and reproduction. In order to systematize knowledge, to preserve information about the diversity of living organisms, it is customary to combine them into systematic groups (classify), guided by common features.
" xml:lang="en-EN" lang="en-EN"> At first glance, all organisms differ from each other to one degree or another, because in the process of evolution each species went its own way, adapting to environmental conditions. But all organisms had and have similar needs Absolutely all have a need for food, which is necessary for energy production, need a certain living space, strive to survive and leave offspring.The simplest forms of organisms are unicellular.They are found among all the main kingdoms of living nature: bacteria , plants, animals and fungi.Single-celled organisms are common in water, soil, air, as well as in the bodies of multicellular organisms.Single-celled organisms have successfully adapted to a variety of living conditions, and make up almost half of the mass of all organisms on Earth.Some of them are autotrophs (contain chlorophyll - the main storage carbohydrate - starch), others - heterotrophs" xml:lang="en-EN" lang="en-EN">(absorption of nutrients by pinocytosis through the membrane or absorption). A distinctive feature of unicellular organisms is a fairly simple body structure. This is a cell that has all the main features of an independent organism. Organelles (from Latin organelle - a diminutive of an organ, i.e. a small organ) cells, like the organs of multicellular organisms, perform various functions. Single-celled organisms reproduce quite quickly and, under favorable conditions, can give two, and sometimes three generations within an hour. under unfavorable conditions, they can form spores covered with dense shells.There are practically no vital processes in spores.Under favorable conditions, the spore again turns into an actively functioning cell.More than a century ago, some scientists (E. Haeckel) proposed to single out unicellular organisms into a separate kingdom, but universal recognition this idea did not receive, because many of them occupy an intermediate position nie. Some unicellular organisms have a clear resemblance to plants, others to animals, others bear signs of both kingdoms, and the fourth are not like anyone else. Prokaryotic unicellular organisms are included only in the kingdom of Bacteria. Single-celled eukaryotes are found in other kingdoms of wildlife. In the kingdom of Plants, these are unicellular algae; in the kingdom of Animals, they are protozoa; in the kingdom of Fungi, they are unicellular yeast fungi.
" xml:lang="en-EN" lang="en-EN">
" xml:lang="en-EN" lang="en-EN">Distinctive features of colonial unicellular organisms
" xml:lang="en-EN" lang="en-EN">Colonial organism is a term that unites two groups;color:#000000" xml:lang="en-EN" lang="en-EN">organism;color:#000000" xml:lang="en-EN" lang="en-EN">s:" xml:lang="en-EN" lang="en-EN">
1) Organisms consisting of many cells, poorly differentiated and not divided into tissues; in many cases, each such cell retains the ability to reproduce;color:#000000" xml:lang="en-EN" lang="en-EN">(Volvox;color:#000000" xml:lang="en-EN" lang="en-EN">green algae;color:#000000" xml:lang="en-EN" lang="en-EN"> pandorina," xml:lang="en-EN" lang="en-EN"> eudorina and others, many groups;color:#000000" xml:lang="en-EN" lang="en-EN">protists;color:#000000" xml:lang="en-EN" lang="en-EN">)." xml:lang="en-EN" lang="en-EN">
" xml:lang="en-EN" lang="en-EN">2) Multicellular organisms that form colonies of several individuals, more or less closely related to each other, usually having the same;color:#000000" xml:lang="en-EN" lang="en-EN">genotype;color:#000000" xml:lang="en-EN" lang="en-EN">" xml:lang="en-EN" lang="en-EN">and general metabolism and regulatory systems. Among animals, such organisms include many species;color:#000000" xml:lang="en-EN" lang="en-EN">coral polyps;color:#000000" xml:lang="en-EN" lang="en-EN">,;color:#000000" xml:lang="en-EN" lang="en-EN">Bryozoans;color:#000000" xml:lang="en-EN" lang="en-EN">,;color:#000000" xml:lang="en-EN" lang="en-EN">sponges" xml:lang="en-EN" lang="en-EN">, etc. In botany, the term "modular" (as opposed to unitary) is used to designate such organisms - these are, for example, rhizomatous cereals, lily of the valley, etc.
" xml:lang="en-EN" lang="en-EN"> The colonial form is a combination of cells that have arisen by asexual reproduction (division) and have not diverged from each other. Individual cells and groups of cells in a colony can be specialized and to function in concert in the interests of the entire colony.In the colony there are two types of cells: vegetative, carrying out movement, nutrition, orientation in relation to the light, and generative, performing the function of reproduction of the colony.The presence of specialized cells to perform certain functions resembles the organization of a multicellular organism with the presence in it colonial protists differ from true multicellular organisms primarily by a lower level of integrity (for example, individual individuals often react to individual stimuli, and not the entire colony as a whole), and colonial protists also have a lower level of differentiation cells In many highly integrated mobile colonies (;color:#000000" xml:lang="en-EN" lang="en-EN">sea pens;color:#000000" xml:lang="en-EN" lang="en-EN">," xml:lang="en-EN" lang="en-EN"> siphonophores, etc.) the level of integrity reaches the level of a single organism, and individual individuals act as organs of the colony. Such (and many other) colonies have a common part(stem, trunk), which does not belong to any of the individuals.
" xml:lang="en-EN" lang="en-EN"> Most colonial organisms in;color:#000000" xml:lang="en-EN" lang="en-EN">life cycle;color:#000000" xml:lang="en-EN" lang="en-EN">" xml:lang="en-EN" lang="en-EN">there are single stages. Usually, after sexual reproduction, development begins with a single cell, which in multicellular animals gives rise to the original multicellular individual. This, in turn, gives rise to colonies as a result of incomplete asexual or vegetative reproduction.In some protists and bacteria, formations similar to colonies (for example, fruiting bodies;color:#000000" xml:lang="en-EN" lang="en-EN">myxomycetes" xml:lang="en-EN" lang="en-EN"> or;color:#000000" xml:lang="en-EN" lang="en-EN">myxobacteria;color:#000000" xml:lang="en-EN" lang="en-EN">)" xml:lang="en-EN" lang="en-EN"> can also be formed in another way - by connecting initially independent single individuals.
" xml:lang="en-EN" lang="en-EN"> It is believed that colonial organisms are a transitional form from unicellular to multicellular organisms. Multicellular organisms differ from colonial organisms in that:
" xml:lang="en-EN" lang="en-EN">1) colonial cells have the same cells, while multicellular ones have different organs and tissues;
" xml:lang="en-EN" lang="en-EN">2) colonials do not have sexual reproduction, but multicellular ones do;
" xml:lang="en-EN" lang="en-EN">3) colonials cannot live on land, but multicellular ones can;
" xml:lang="en-EN" lang="en-EN">Description of some unicellular colonial organisms
" xml:lang="en-EN" lang="en-EN">Building bacterial cell. " xml:lang="en-EN" lang="en-EN"> Sizes - from 1 to 10 microns. The shape of a bacterial cell can be very diverse. Spherical bacteria are divided into several forms according to the arrangement of cells after division: monococci - single; diplococci - form pairs; tetracocci - form tetrads; streptococci - divide in one plane, form chains; staphylococci - divide in different planes, form clusters resembling bunches of grapes; sarcins form packages of 8 individuals.
" xml:lang="en-EN" lang="en-EN">Another group, autotrophs, is capable of synthesizing organic substances from inorganic ones. Among them, there are: photoautotrophs, synthesizing organic substances due to light energy, and chemoautotrophs, synthesizing organic substances due to the chemical energy of the oxidation of inorganic substances: sulfur, hydrogen sulfide, ammonia.These include, for example, nitrifying bacteria, iron bacteria, hydrogen bacteria.
" xml:lang="en-RU" lang="en-RU">Spore formation in bacteria is a way of experiencing adverse conditions. Spores are usually formed one at a time inside the “mother cell” and are called endospores. Spores are highly resistant to radiation, extreme temperatures , drying and other factors that cause the death of vegetative cells.At the same time, the cell is dehydrated, the nucleoid is concentrated in the sporogenous zone.Protection shells are formed that protect bacteria spores from adverse conditions (the spores of many bacteria withstand heating up to 130°C and remain viable for decades). When favorable conditions occur, the spore germinates and a vegetative cell is formed.
" xml:lang="en-EN" lang="en-EN">Reproduction" xml:lang="en-EN" lang="en-EN">. Bacteria reproduce only asexually - by dividing the "mother cell" in two or by budding. DNA replication occurs before division, some bacteria, under favorable conditions, are able to divide every 20 minutes .
" xml:lang="en-EN" lang="en-EN">Bacteria never form gametes, cell content does not merge, but genetic recombination takes place, in which DNA is transferred from a donor cell to a recipient cell .
;color:#000000" xml:lang="en-EN" lang="en-EN">Green algae can also form colonies. The most interesting in this respect is the Volvox colony, which is more like a multicellular organism. The coordinated beating of the flagella provides directional movement "Reproductive cells responsible for reproduction are located on one side of the colony. Thanks to them, daughter colonies are formed inside the mother colony, which then separate and go on to independent existence. Green balls up to 1 mm in diameter floating in the water can be found in ponds and lakes. Until now until the end it is not clear which kingdom this organism belongs to, since signs of both animals and plants are manifested in the structure and life activity.That is why Volvox is referred either to colonial algae or to colonial protozoa - flagellates.Each ball consists of many cells (more than a thousand), similar to green euglena.The cells are pear-shaped and 2 flagella, interconnected cytoplasmic bridges. The bulk of the ball is a semi-liquid gelatinous substance. The cells are immersed in it at the very surface, so that the flagella stick out. Thanks to the movement of the flagella, the Volvox rolls in the water ("volvox" means "rolling", also called the "top"). Each cell looks like an independent protozoan, but together they form a colony, because they are connected to each other. This explains the coordinated work of the flagella of the entire colony. In the middle are 16 reproductive cells called gonidia. There are also some dioecious types of Volvox (Volvox golden). The coordinated beating of the flagella provides directional movement. Reproductive cells responsible for reproduction are located on one side of the colony. Thanks to them, daughter colonies are formed inside the mother colony, which then separate and move on to an independent existence. The primary differentiated stage in the evolution of a multicellular organization is characterized by the beginning of specialization according to the principle of "division of labor" in the members of the colony, not only Volvox globator (thousands of cells), but also in the colonies of Pandorina morum (16 cells), Eudorina elegans (32 cells). Specialization in these organisms is reduced to the division of cells into somatic cells, which perform the functions of nutrition and movement (flagella), and generative cells (gonidia), which serve for reproduction.
;color:#000000" xml:lang="en-EN" lang="en-EN">" xml:lang="en-EN" lang="en-EN">According to the nature of development, monotomic and palintomic colonies are distinguished. Monotomy is such a method of asexual reproduction, in which, after the act of separation, the daughter individuals grow and restore all the organelles characteristic of the mother cells.Individual cells of the colonies periodically divide, increasing the number of individuals that make up the colony.From time to time, the colony itself, which has reached the maximum size for a given species, is laced in half.In this way, an increase in the number of colonies is carried out.In polyntomic colonies, which, for example, include plant flagellates of the Volvox family. Reproduction is different. All or only some of the cells of the colony undergo successive polytomic divisions, resulting in several young colonies at once. The entire maternal colony breaks up into daughter colonies, the number of which is equal to the number of cells of the old colony. Volvox has only a few cells of the maternal colony undergo n alintomic division. The resulting daughter cells are first placed inside the mother cell. After some time, the old colony collapses and those located inside it become free. In such a complex colony as Volvox, most of the cells do not give rise to the next generation, but periodically die.;color:#000000" xml:lang="en-EN" lang="en-EN">According to the method of nutrition, Volvox algae are autotrophs and contain a green pigment;color:#000000" xml:lang="en-EN" lang="en-EN">chlorophyll;color:#000000" xml:lang="en-EN" lang="en-EN">. The pigment is located in the algae cell in a special ribbon or star-shaped organelle called the chromatophore.
" xml:lang="en-EN" lang="en-EN">;color:#000000" xml:lang="en-EN" lang="en-EN">Colonial plants include various unicellular algae: blue-green, green, golden, yellow-green, diatoms, pyrophytes, euglenoids. according to the method of formation of colonies, they are divided into zoospores and autospores (they reproduce by zoospores or autospores).Among heterotrophic flagellates and;color:#000000" xml:lang="en-EN" lang="en-EN">ciliates;color:#000000" xml:lang="en-EN" lang="en-EN"> there are also many colonial forms. There are colonial;color:#000000" xml:lang="en-EN" lang="en-EN">radiolarians;color:#000000" xml:lang="en-EN" lang="en-EN">.
;color:#000000" xml:lang="en-EN" lang="en-EN"> Algae are autotrophs by way of feeding and contain green pigment;color:#000000" xml:lang="en-EN" lang="en-EN">chlorophyll;color:#000000" xml:lang="en-EN" lang="en-EN">. The pigment is located in the algae cell in a special ribbon or star-shaped organelle called;color:#000000" xml:lang="en-EN" lang="en-EN">chromatophore. One of" xml:lang="en-EN" lang="en-EN"> the most ancient algae -;color:#000000" xml:lang="en-EN" lang="en-EN">" xml:lang="en-EN" lang="en-EN">blue-green algae, the oldest representatives of the plant world. The total number of species is about 1400 (150 genera). These are unicellular or colonial organisms. They are characterized by a variety of colors - blue-green , olive, dark green, due to pigments that are contained in cells in different combinations.The main difference between blue-green algae and other algae is the absence of a nucleus, chromatophores, vacuoles and true mitochondria in the cells.The cell wall is pectinous and easily mucilaginous.Often unicellular or filamentous colonial organisms covered with a mucous membrane and, as a result of immersion in the thickness of the mucus, form rather large colonies.Colonial algae, as a rule, have the form of filaments made up of cylindrical or spherical cells.Among the homogeneous cells that make up the colony, larger thick-walled dead cells with yellow-brown contents stand out These are heterocysts.
" xml:lang="en-EN" lang="en-EN"> Physiologically, all blue-greens are typical photosynthetics. However, many of them, living in water bodies polluted with rotting residues, feed mixotrophically (mixed).
" xml:lang="en-EN" lang="en-EN"> Blue-green algae never form flagellar forms or stages. They reproduce asexually, mainly vegetatively. There is no sexual reproduction. The areas of the colony that serve for vegetative reproduction are called hormogonia. During asexual reproduction, spores are formed from ordinary living cells, surrounded by a thick wall, often having various outgrowths.In the form of resting cells - "spores" blue-green algae survive adverse conditions.The colony of the first kind is the green algae pediastrum; in the cells of its 16-cell colony, there are, after fission of the nucleus and splitting of the protoplasm, 16 biflagellated zoospores each, having left the mother's membrane in the mucous membrane, the zoospores, having moved, lose their flagella, adjoin each other, form hard shells and coalesce into a new 16-cell tabular colony. bring flint algae gomphonema: its cells secrete through small perforations of the shell at one end there is mucus of a dense consistency, forming a “leg” or “stalk”; cells, multiplying by division and forming "legs", are articulated into a colony - a complex of cells, the legs of which, consisting of hardened mucus, make up something in the whole in the form of a bush.
" xml:lang="uk-UA" lang="uk-UA">Comparative characteristics of some other" xml:lang="en-EN" lang="en-EN">algae departments
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" xml:lang="en-EN" lang="en-EN">Department " xml:lang="en-EN" lang="en-EN">Features |
" xml:lang="en-EN" lang="en-EN">Green |
" xml:lang="en-EN" lang="en-EN">Diatoms |
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" xml:lang="en-EN" lang="en-EN">1. Number of views |
" xml:lang="en-EN" lang="en-EN">`15ths. |
" xml:lang="en-EN" lang="en-EN">`15ths. |
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" xml:lang="en-EN" lang="en-EN">2. Organization of the vegetative body (unicellular, colonial, multicellular) |
" xml:lang="en-EN" lang="en-EN">unicellular, colonial, multicellular |
" xml:lang="en-EN" lang="en-EN">unicellular, colonial |
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" xml:lang="en-EN" lang="en-EN">3. Location |
" xml:lang="en-EN" lang="en-EN"> |
" xml:lang="en-EN" lang="en-EN">Fresh and salt water bodies, wet ground |
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" xml:lang="en-EN" lang="en-EN">4. Cell structure (staining, organelles) |
" xml:lang="en-EN" lang="en-EN">There are flagella, green plastids |
" xml:lang="en-EN" lang="en-EN">Silicon carapace of two wings, yellow-brown pigments |
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" xml:lang="en-EN" lang="en-EN">5. Reproduction |
" xml:lang="en-EN" lang="en-EN">Sexual, asexual, vegetative |
" xml:lang="en-EN" lang="en-EN">Sexual, vegetative |
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" xml:lang="en-EN" lang="en-EN">6. Representatives |
" xml:lang="en-EN" lang="en-EN">Chlamydomonas, volvox, chlorella, ulotrix, spirogyra |
" xml:lang="en-EN" lang="en-EN">Pinularia, navicula, tsinbela |
" xml:lang="en-EN" lang="en-EN">
" xml:lang="en-EN" lang="en-EN">The meaning of colonial unicellular organisms.
" xml:lang="en-RU" lang="en-RU">The importance of bacteria. Bacteria are of great importance both in the biosphere and in human life. Bacteria take part in many biological processes, especially in the circulation of substances in nature. bacteria in nature is determined by the fact that they are all heterotrophic.By mineralizing dead organisms of plants and animals, they return to the biological cycle the mineral substances used by autotrophic green plants in the process of photosynthesis and water-mineral nutrition.The process of protein breakdown as a result of bacterial activity is called decay, and decomposition of carbon-containing non-protein substances - by fermentation. Putrefactive bacteria destroy nitrogen-containing organic compounds of inanimate organisms, turning them into humus. Mineralizing bacteria decompose complex organic compounds of humus into simple inorganic substances, making them available to plants.
" xml:lang="en-EN" lang="en-EN"> Many bacteria can fix atmospheric nitrogen. Moreover, Azotobacter, free-living in the soil, fixes nitrogen independently of plants, and nodule bacteria show their activity only in symbiosis with roots of higher plants (mainly legumes), thanks to these bacteria, the soil is enriched with nitrogen and the productivity of plants increases.Atmospheric nitrogen is fixed and cyanobacteria.
" xml:lang="en-EN" lang="en-EN">Symbiotic bacteria in the intestines of animals (primarily herbivores) and humans ensure the absorption of fiber.
" xml:lang="en-EN" lang="en-EN">Bacteria are not only decomposers, but also producers (creators) organic matter which can be used by other organisms. Compounds formed as a result of the activity of bacteria of one type can serve as an energy source for bacteria of another type.
" xml:lang="en-EN" lang="en-EN">In addition to carbon dioxide, during the decomposition of organic matter, other gases also enter the atmosphere: H2, H2S, CH4, etc. Thus, bacteria regulate the gas composition of the atmosphere.
" xml:lang="en-RU" lang="en-RU">Some substances formed during the life of bacteria are also important for humans. acids, alcohols, acetone, enzymatic preparations; currently, bacteria are actively used as producers of many biologically active substances (antibiotics, amino acids, vitamins, etc.) used in medicine, veterinary medicine and animal husbandry.
" xml:lang="en-EN" lang="en-EN">Thanks to genetic engineering methods, with the help of bacteria, such necessary substances as human insulin, growth hormone, interferon are obtained.
" xml:lang="en-EN" lang="en-EN">" xml:lang="en-RU" lang="en-RU">The role of algae in nature and human life is enormous. Together with higher plants and chemosynthetic bacteria, they form a group of producers, due to the vital activity of which all other non-photosynthetic organisms exist. Algae serve as food, shelter and breeding grounds for many marine animals.Terrestrial species are the pioneers of vegetation, settling in lifeless and barren places.In practice, they use the property of algae to form organic substances and oxygen.Algae are widely used in laboratory and space research.
" xml:lang="en-EN" lang="en-EN"> Speaking about the economic importance of blue-greens, their role as causative agents of water “blooming” should be put in the first place. Unfortunately, this is a negative role. Positive their importance lies primarily in the ability to assimilate free nitrogen.Among blue-green algae, there are species that can fix atmospheric nitrogen, combining this process with photosynthesis. major cities and industrial centers, they serve as indicators of pollution atmospheric air nitrogen oxides. In eastern countries, blue-green algae are even used for food, and in last years some of them have found their way into mass culture basins for the industrial production of organic matter. In agriculture, algae are used as organic fertilizers (nitrogen-fixing blue-green algae, their masses are collected during the "bloom" of reservoirs). Blue-green algae cause the formation of humus, improve soil aeration, and affect its structure.
" xml:lang="en-EN" lang="en-EN"> In sanitary hydrobiology, blue-green algae are used as indicators showing the degree of water pollution with organic substances. Algae is used in industrial water treatment.
" xml:lang="en-EN" lang="en-EN"> Pyrophytic algae are widely distributed in sea and fresh waters. In the seas and oceans, together with diatoms, they form the basis of plant plankton. Some of them (Nightlight, etc.) cause the night glow of the sea." xml:lang="en-RU" lang="en-RU">Pyrophytes are actively involved in the circulation of substances in water bodies. Many of them, living in polluted and waste waters, perform the function of active orderlies, participate in the self-purification of these waters.
" xml:lang="en-EN" lang="en-EN"> diatoms live in the seas, fresh waters and on moist soil. They have great importance as the creators of organic matter in the hydrosphere, in the seas and oceans, they make up the bulk of the plant part of plankton, can exist at a depth of up to 100 m. Diatoms play a primary role in sedimentation, forming diatom silts on the bottom of the ocean, seas and freshwater reservoirs. In sea bays polluted with organic substances, they participate in the processes of natural water purification. In terms of nutritional value, diatoms are superior to potatoes and cereals: the content of proteins and fats in them is higher.
" xml:lang="en-RU" lang="en-RU">The value of yellow-green algae in nature lies in the fact that, along with other phytotrophic organisms, they create the primary production of water bodies and enter the food chain of hydrobionts, along with other algae cause the deposition of sapropels actively participate in the accumulation of organic matter.The ability of most species of euglenophytes to mixotrophic (mixed) or completely saprophytic nutrition allows them to actively participate in the self-purification of water bodies polluted with organic substances.
" xml:lang="en-EN" lang="en-EN">
" xml:lang="en-EN" lang="en-EN">References:
" xml:lang="en-EN" lang="en-EN">1..Marfenin N.N. The phenomenon of coloniality. M., Publishing House of Moscow State University, 1993.
" xml:lang="en-EN" lang="en-EN">2.Nebel B.;color:#000000" xml:lang="en-EN" lang="en-EN">Science;color:#000000" xml:lang="en-EN" lang="en-EN">" xml:lang="en-EN" lang="en-EN">about environment. How the world works. M., 1993.
" xml:lang="en-EN" lang="en-EN">Ivanova T.V. Biology. 2002.
" xml:lang="en-EN" lang="en-EN">3. Mednikov B. Biology of the form and standard of living, 1994
" xml:lang="en-EN" lang="en-EN">4. Gilbert S. Developmental biology. v.1, 1993
" xml:lang="en-EN" lang="en-EN">5. "Plant life - algae" A.A. Fedorov, A.L. Kursanov, N.V. Tsiuin, M.V. Gorlenko, S. R. Zhilin.
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colonial organism- a term that combines two groups of organisms:
- Organisms consisting of many cells, poorly differentiated and not divided into tissues; in many cases, each such cell retains the ability to reproduce (Volvox green algae, etc., many species of jack-o'-lanterns, and other groups of protists).
- Multicellular organisms that form colonies of several individuals more or less closely related, usually sharing the same genotype and common metabolism and regulatory systems. Among animals, such organisms include many types of coral polyps, bryozoans, sponges, etc. In botany, the term “modular” (as opposed to unitary) is used to refer to such organisms - these are, for example, rhizomatous cereals, lily of the valley, etc.
Distinctive features of colonial organisms
Colonial protists differ from true multicellular organisms primarily in a lower level of integrity (for example, individual individuals often react to individual stimuli, and not the entire colony as a whole), and colonial protists also have a lower level of cell differentiation. In many highly integrated mobile colonies (sea feathers, siphonophores, etc.), the level of integrity reaches the level of a single organism, and individual individuals act as organs of the colony. Such (and many other) colonies have a common part (stem, trunk) that does not belong to any of the individuals.
colony formation
Most colonial organisms have single stages in their life cycle. Usually, after sexual reproduction, development begins with a single cell, which in multicellular animals gives rise to the original multicellular individual. She, in turn, gives rise to a colony as a result of asexual or vegetative reproduction that has not been completed.
In some protists and bacteria, formations similar to colonies (for example, the fruiting bodies of myxomycetes or myxobacteria) can also be formed in another way - by combining initially independent single individuals.
Examples
Prominent representatives of colonial organisms are colonial green algae (for example, Pandorina, Eudorine, as well as volvox, which is a transitional form to true multicellular organisms). Colonial forms are also widespread among other groups of algae - diatoms, golden, etc. There are also many colonial forms among heterotrophic flagellates and ciliates. There are colonial radiolarians.
Most of the animals are colonial