Main article: Protos
Seaweed ( Algae. )- These are trains capable of photosynthesis.
Algae includes unicellular and multicellular organisms capable of carrying out photosynthesis, since chloroplasts are contained in their cells. Algae have different shapes and sizes. They live mainly in water to the depths where the light penetrates.
Among the algae there are both microscopically small and gigantic, reaching lengths of more than 100 m (for example, the length of the drier algae of macrocystis pear-shaped 60-200 m).
In algae cells, special organoids are contained - chloroplasts that are carried out photosynthesis. In different species, they have different shapes and sizes. Mineral salts necessary for photosynthesis and carbon dioxide algae are absorbed from the water with the entire surface of the body and is isolated into the surrounding oxygen.
In freshwater and marine reservoirs, multicellular algae is widespread. The body of multicellular algae is called a layer. A distinctive feature of the layer is the similarity of the structure of the cells and the absence of organs. All cells of the layers are almost the same, and all parts of the body perform the same functions.
We multiply algae with sexual and gender methods.
Unicellular algae multiply, as a rule, division. Military reproduction of algae is also carried out by means of special cells - spores covered with a shell. Disputes of many species have flagella and capable of moving independently.
For algae, sexual reproduction is characteristic. In the process of sexual reproduction, two individuals participate, each of which transfers its chromosome to the descendant. In some species, this transmission is carried out when the content of the conventional cells is merged, the other adhesive sex cells are sticking - grounds.
Water habitat algae
Algae live predominantly in water, population of numerous marine and freshwater reservoirs, both large and small, temporary, both deep and small ones.
Algae inhabit the reservoirs only on the depths that sunlight penetrates. Few types of algae dwell on the stones, tree bark, soil. For habitat in water, algae has a number of devices.
For organisms living in the oceans, seas, rivers and other water bodies, water is a habitat. The conditions of this environment differ markedly from terrestrial conditions. For water bodies, a gradual weakening of illumination is characterized as it immerses the depth, temperature fluctuations and salinity, low oxygen content in water is 30-35 times less than in the air. In addition, for seaweed, the water movement is greater danger, especially in the coastal (tidal-tidy) zone. Here, algae is exposed to such powerful factors as the surf and blows of waves, flows, tides (Fig. 39).
Survival of algae in such harsh conditions of the aqueous medium is possible due to special devices.
- With a lack of moisture, the shell of algae cells are significantly thickened and impregnated with inorganic and organic substances. This protects the body of algae from drying during the low tide.
- The body of marine algae is firmly attached to the soil, so during the surf and shocks of the waves, they relatively rarely remove from the soil.
- In deep-water algae there are larger chloroplasts with a high content of chlorophyll and other photosynthetic pigments.
- Some algae has special bubbles filled with air. They, like floats, hold alga at the surface of the water, where it is possible to capture the maximum amount of light for photosynthesis.
- The output of the dispute and heams from seaweed coincides with the tide. The development of zygotes occurs immediately after its formation, which does not allow the chip to carry it into the ocean.
- The kingdom of bacteria
- Eukarotes, or nuclear
- Treatment of Archeplastide
- Kingdom Glaucafitis
- Kingdom Red Algae.
- Kingdom Green Algae.
- Kingdom Harovy Algae.
- Treatment of excavati
- Treatment of Rizariya
- The kingdom of churches
- Type chlorachnofitic algae
- The kingdom of churches
- Treatment of Stranopyl
- The kingdom of okewpovy algae.
- Type diatoms algae
- Type of yellow-green algae
- Type of brown algae
- Type Golden Algae.
- The kingdom of okewpovy algae.
- Treatment of alveolat
- Hacrobia system
- Kingdom cryptophyted algae
- The kingdom of garptophyte algae
- Treatment of Archeplastide
Representatives of algae
In the seas live algae having yellow-brown coloring. These are brown algae. Their painting is due to high content in cells of special pigments.
The body of brown algae has the kind of threads or plates. A typical representative of brown algae - laminaria (Fig. 38). It has a lamellar body up to 10-15 m long, which is attached to the substrate with the help of rhizoids. Laminaria is multiplied with sexual and sexual ways.
In shallow water thick thickets forms fus. His body is more dismembered than at Laminaria. In the top of the layer, there are special bubbles with air, so that the body of the fukus is held on the surface of the water.
see the meaning of algaeOn this page, material on the themes:
What depth is algae golden
Algae feature tool to aquatic environment
Device of algae to the water habitat
Fukusy than feed on how to multiply
At the greatest depths can dwell by algae
What organisms relate to algae?
It is known that algae inhabit the sea, rivers and lakes only at the depths that sunlight penetrates. How can this be explained?
What is common and distinctive in the structure of unicellular and multicellular algae?
What is the main difference between brown algae from other algae?
Compare groups of rubbers (heterotrophic, autotrophic and auto accumulate). What are the signs common to all groups and distinctive for each group?
What adaptations to habitat in water are available at algae?
Many algae inhabit in the tidal and tidal zone. Why do not take them in the sea at the point?
Why many sea algae live at a depth of no more than 200 m, while other organisms live much deeper?
Marine macrophytes - The world's largest algae. These multicellular organisms are greater than all other algae resemble green plants: their tallons are often branched, externally similar to the stalk covered with leaves. Another feature, common with plants, is the need for sunlight for photosynthesis. That is why they cannot grow at great depths where sun rays do not penetrate. Some species of these algae float freely, others are attached to the stones in the adorption zone or at the bottom of the sea. The picture shows brown algae.
which in the classification used here enters together with golden and yellow-green algae into the Chrysophyta department (type) of the Kingstikov. The diatoms are a very extensive group of single-celled sea and freshwater species. Coloring them from yellow to drier due to the presence of fucoxanthin pigment. The protoplastic diatomace is protected by a box silica (glass) shell - a shell consisting of two sash. The solid surface of the sash is often covered with a complex pattern characteristic of a complex pattern of strokes, tubercles, pits and ridges. These shells are one of the most beautiful microscopic objects, and the clarity of the distinction of their pattern is sometimes used to check the microscope resolution. Typically, the sash are pierced or have a slit called seam. The codro is in the cage. In addition to cell division, sexual reproduction is also known. Many diatoms are free-peeling forms, but some are attached to underwater objects with mucous legs. Sometimes cells are combined into the threads, chains or colonies. There are two types of diatoms: Cutter with elongated double-sample-symmetric cells (they are most abundant in fresh waters) and centric, whose cells, if you look from the sash, look round or polygonal (they are most in the seas). As already mentioned, the shells of these algae persist after the death of the cells and settled on the bottom of the reservoirs. Over time, their powerful clusters are compacted in the porous rock area - diatomitis.
Diatoms - An extensive group of single-celled sea and freshwater algae. Cells of some of their species are connected in direct or zigzag chains. Unlike other algae, diatoms are protected by a silica carcire of two sash, one of which is larger than the other and covers it like a soap cap. Folds are often covered with a complex pattern, so under the microscope, many diatoms resemble jewelry fine work. Depending on how their shells looks like on the side of the sash, these algae are divided into two groups - centric and filas. In the first - radial symmetry, the second - the cells are oblong and symmetry bilateral (sometimes they are somewhat asymmetrical). Micrographs show centric diatoms. Flagery. These organisms in connection with their ability to "animal" nutrition and a number of other important signs are now often referring to the concentration of the simplest (Protozoa) of the kingdoms, but they can be considered as not included in Protozoa (type) Euglenophyta. of the same kingdom All flask single-celled and movable. Cells - green, red or colorless. Some species are capable of photosynthesis, while the other (saprophytes) absorb the dissolved organic or even swallow solid particles. Sexual reproduction is known only in some species. The usual inhabitant of ponds - Euglena, green algae with red "peak". It floats with a single flavor, capable of both photosynthesis and nutrition of the finished organic. At the end of the summer, Euglena Sanguinea can paint the pond water in red. Dinoflasels. These unicellular harness organisms are also common to the simplest, but they can be allocated to the independent department (type) of Pyrrophyta kingdom of rubbers. They are mostly yellow-brown, but come colorless. Their cells are usually mobile; There is no cell wall in some species, and sometimes there is a very bizarre form. Sexual reproduction is known only in a few species. The genus Gonyaulax is one of the reasons for "red tides": the coasts are so far enough that the water acquires a unusual color. This algae releases toxic substances, sometimes leading to the death of fish and mollusks. Some dinoflates cause phosphorescence of water in the tropical seas. Golden algae Included along with others in the department (type) Chrysophyta. Kingdom of rubbers. The color is yellow-brown, and the cells are movable (flavored) or immobile. The reproduction is intact with the formation of a silica cyst. Yellow-green algae Now it is customary to unite with golden in the department (type) Chrysophyta, but you can consider them and the independent department (type) of the Xanthophyta kingdom of protists. In form, they are similar to green algae, but are distinguished by the predominance of specific yellow pigments. Their cell walls sometimes consist of two partners in each other, and the nital species have these sash in the longitudinal section of the N-shaped. Sexual reproduction is known only in a few forms. Harovy (rays) - multicellular algae, components of the department (type) Chariophyta. Kingdom of rubbers. Coloring them varies from grayish green to gray. Cell walls are often incrouted by calcium carbonate, therefore, dead remnants of Harov are involved in the formation of Mergel's deposits. These algae has a cylindrical, resembling the main axis stem, from which the side processes are departed, similar to the leaves of plants. Roughly rude vertically on shallow water, reaching a height of 2.5-10 cm. Reproduction of sexual. Harov is hardly close to any of the above groups, although some botany believe that they originated from green algae. See also plant systematics.
The encyclopedia of the colley. - Open Society . 2000. .
Seaweed Photosynthetic organisms that produce their own food by absorbing the strength of sunlight. They must combine sunlight with photosynthetic cells, carbon dioxide, minerals and water to create sugars.
Seaweed Usually have abundant water and carbon dioxide in their environment, and the restrictive factor will often be sunlight or minerals. This explains why the population of algae can sometimes blow when the levels of sunlight or the mineral body content of water change.
Seaweed Completed in many water habitats. They grow in ponds, lakes, rivers, streams, streams, puddles, reservoirs and waterfalls. However, they also grow in very wet, but not water habitats.
For example, the stones surrounding the stream or river can be so wet to keep the lush carpet from algae. Caves and other places can also be wet enough to maintain the growth of algae. Tropical forests are sometimes wet enough so that algae grew on the trunks of the trees.
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SEAWEED (Algae, or PhyKos), a group of lower phototrophic organisms that live in origin in origin. in reservoirs. Traditionally, they treated the kingdom of plants, in which almost all departments and classes of V. (green, red, brown, dinophyte, diatoms, evglen and others) were isolated on the basis of a set of pigments present in cells and morphologic. Signs. In Sovr. GL-based systems arr. At the criteria for the subtle structure of cell organelles, some departments of V. are placed in themselves. The kingdoms, while in a number of them v. unite with off. Groups of mushrooms and simplest.
Structure, food and reproduction of algae
Body V. (Loader, or Tallom), unlike higher plants, is not differentiated for root, stem, leaves and components of their fabrics and does not have a single structure plan. OSN. A photo auto-thread type of food does not exclude their ability to switch to photogometrophertic nutrition and absorb dissolved organic. Connections into light or in the dark (like mushrooms) or small particles (like animals). Power is carried out by the entire surface of the layer. Set photosynthetic. Pigments in V. of different departments consists of a combination of chlorophylls a, b, c, Fikobilins, Carotes, Ksantofilles. Spare nutrients - Split. Forms of starch and other polysaccharides, lipids.
Cell V. is characterized by an extreme manifold of the structure of its elements and a number of specifics. heck. Cell coverings in primitive single-cell forms are represented only by external cytoplasmatic. The membrane (plasma), not fixing the shape of the cell, and next to. Pokrovov (scales, etc.). In the higher organized V. there are cell walls, the OSN. The structural unit of which is cellulose. They also include other polysaccharides (including having grinding properties of agar Red V.), proteins (including glycoproteins), salts of iron, calcium and silicon forming the semblance of the shell, etc.
V. - Eukaroto. Their chloroplasts, in contrast to higher plants, are diverse in shape, quantity and location in a cell, a thin structure and are deprived of the real Grand Prix. Only V. has special calf - Pyrenoids that serve as a place of formation of starch. Movement V. With the help of temporary growing, cilia or flagella brings them closer with animals. The flagellas occur in almost all representatives of V. either as an alteration. Unicellular organisms, or as deposited. Stages in the life cycle. The flavor apparatus consists of a flagella, basal body and flaky roots with complex ultrastructure. In the rolling cells V. there are peculiar organelles: photosensitive stigma (peephole), functionally connected with a flavor apparatus and chloroplast, as well as centrioles (similar to the basal bodies of flavors) inherent in animals and the absence of higher plants.
Seaweed. B y E: 1 - fucus bubble (Fucus vesiculosus); 2 - Laminaria Saccharia (Laminaria Saccharina); 3 - Alaria Edible (Alaria Esculenta); 4 - Sargassum mixed ...
B. Present unicellular, colonial, multicellular, non-silica; They vary them from several microns (chlorella) to 40-50 m (nonreocystis). Such a variety of V. can be reduced to several OSN. Types of structure reflecting the stages of their morphologic. Evolution and its parallelism in different departments. At unicellular V. allocated: an amosboid type - naked cells, devoid of flavors; Monad - cells with flagellas; Coccoid - cells with shell, fixed; Also distinguished single forms, colonies (clusters of an indefinable number of cells of different generations combined with mucus or specials. Growth) and centions (colonies formed by a fixed number of cells of one generation). Among the multicellular V. is the most common type of structure. The planting can be in the form of a simple or branched single-row cell thread (Ullitrix). As the branching and differentiation of cells are complicated: a disretened type of structure, which differs from the substrate and the vertical part of the layer; A complex pseudo-plane structure (in brown and red V.) with the specialization of cells on the outer assimilation and internal performing stocking, mechanical. and conductive functions like tissues of higher plants (laminaria); Specific. Harov structure. The parenchymal type occurs when cell division in 2-3 planes (ulva, porphyra). A special type of structure is a siphonic (guideline), when the layer, is often macroscopic and complexly dissected, devoid of cellular partitions and is one giant multi-core cell (cauleparapa, acetabulary). Multicolve V. are attached to the substrate with solid soles or nichtage increases - rhizoids. Morphologically V. Different types of structure are very diverse. In highly organized forms, the layered externally can be disseminated on sheet and stroke parts. The growth of the layer diffuse if cell division occurs in any part of it; If it is timed to a certain growth zone - apical, intercalar (in cf. parts of the layer), basal.
The reproduction is vegetative, cull and sex. At unicellular V. Vegetative reproduction It is carried out by dividing the cell that in the formation of child cells similar to the maternal, fragmentation of the colonies, by repeated divisions in the centrability forming new miniature cobbles; In multicellular V. - fragments of layers, specials. Vegetative formations (Jar of Hara, Propagulas in Sfatolery) will complement. Espare in the basal part of the attached forms, etc. Only unwinded unreasted forms of bottom macrosways, capable of forming major clusters (anhylic, cavetopore, sargassa, phillorophore, enteromorph). Dust reproduction Inherent in most V., is associated with the formation of specials. Cells - spores growing in new individuals after leaving the maternal cell - sporangium. We simply organized by V. Sports serve ordinary vegetative cells, in more specialized - morphologically differentiated, performing only the function of formation of the dispute. OSN. Types of dispute: zyospore - movable, have flagellas (from 1-4 to many in different groups) are characteristic of most in.; Aplaneport is fixed (among them there are autosorps forming their own shell inside the maternal cell; hystostor - with a thickened shell capable of a long state of rest). Sexual reproduction In the simplest form, it is reduced to the merger of vegetative cells - Gololine in Zhgutikov I. conjugation At lifeless. Most V. are formed a specialtipography. Sex cells - Gamets in undifferentiated or special. cells - Gamentangia . Sectional types: Isoamy - Movable Gamets, identical in size and shape; Anisogamy - Gamets Movable, women's larger male; Oogamia - Women's Gameta is deprived of flavors, much larger male. Men's gamets are movable in all V., with the exception of red and combins.
With the advent of the sexual process and heams in the process of evolution, the specialization of individuals on the formation of dispute or games and the occurrence of sexual (Gametophyte) and clarifications (spores) forms of development, including the change of morphological and nuclear phases, is gradually occurring. Spores germinate into same-sex or two-fallen gametophytes, giving grounds. As a result of the merger of Games, the zygote is formed, germinating in sporophyte. With all the diversity of development cycles, 3 OSN stands out. Type, depending on the place of Maizo: Gaplophaus - diploid only zygota, meyosis occurs when it is germination; Diplogaplohas-spore diploid, gametophyte haplopoid, meyosis during spores - sexual and forms of development exist independently, they may be morphologically similar (isomorphic cycle) or different (heteromorphic cycle); Diplophase - the body exists in the diploid phase, meyosis - in the formation of Games.
Spreading in nature and environmental groups of algae
It is known to OK. 50 thousand species V. They inhabit all possible habitats and form a lot of environmental. Groupings. In marine and continental reservoirs of all types of V. live in the thickness of water, forming phytoplankton, in the surface film zone (neutron), at the bottom of the reservoirs (phytobenthos); They settle on different soils, as well as on arts. Constructions, the bottom of the courts (periphyton). The distribution of V. in reservoirs affect their hydrodynamic. Features, illumination, tempo, the presence of biogenous substances. Single-cellular B is dominated in phytoplankton: in fresh reservoirs - green, in the seas - diatoms and dinophite. Fitobenthos is attached by V., which grow on solid and loose soils, on plants and animals or inside them. In fresh reservoirs, small forms predominate, penetrating into a depth of several meters. Fitobentos of the seas will be lighted. Macrofit - green, brown and red V., who inhabit the tidal zone and the upper sections of the shelf to a depth of 40-50 m, as an exception - up to 200 m. Moderate and cold waters of the seas dominate large fukusovy and laminarium in.; In their thickets, rich species of multi-tiered high-productive communities are formed, the biomass of which can reach 40-100 kg per 1 m 2bottom. As a result of the eutrophication of the coastal zone of the seas and inerational fishery, the disappearance of large perennial species and the associated hydrobionts, depletion and simplification of the structure of aquatic biocenoses are disappeared.
OK. 2 thousand species V. (ch. Ob. Green) grow on the surface of the soil and in its thicker. Aerofil V. live in an air environment in conditions of insignificant periodic. Moisturizing on a variety of substrates - the crust and leaves of plants, rocks, wooden and stone structures, etc. They are developing in extreme conditions - in hot springs (diatoms), in the snow (eg, chlamydonas Snowy, having red coloring snow) , Ice (diatom). There is a t. N. Drilling V., capable of introducing into a limestone (microscopic. Green), and V., excreasing lime (litaming). B., living on other organisms, use them as a substrate, parasitize on them or enter with them in symbiosis. The most interesting symbiosis of some V. with mushrooms, which led to the formation of new organisms - lichens, and with coral polyps, providing the existence of self-sustaining biological, due to the ability of V. to photosynthesis. Coral reef systems.
The role of algae in nature and their use
The role of V. in nature is determined primarily by the fact that they are oxygen and organic producers. Compounds, initial food chains in reservoirs and, thereby, determine the very existence of aquatic ecosystems. Their total primary products are on average approx. 50% of the total primary products on the planet. B. Participate in the processes of self-purification of polluted water, are capable of absorbing in high concentrations heavy metals from the environment; Filming, they play a large role in sedimentation, in the formation of ils, sapropel, therapeutic mud. Donate V. Thickets create animal habitats. Geologic. The value of V. as an ancient organisms (known from Precambria) consists in the formation of some rocks - diatomites, limestone, tuffs, combustible shale - and in participating in the cycle of substances in nature. Excessive development of V., provoked farms. Human activity causes "blooming" of water bodies, often existing destructive on animals and humans (see Eutrophication of reservoirs ). Soil values are involved in the creation of humus, including primary (on barren areas of sushi). B. contains digestible carbohydrates, proteins, rich in vitamins and microelements, have dietary and therapeutic properties. Therefore, they are widely used in food (Porphira, Laminaria, Ulwa, Spirulina, etc., total approx. 150 species), as feed for livestock (fus, laminaria, chlorella), for fertilizer (in seaside regions). Colloids of red and brown V. (Agaras, carrageans, alginates) are used as emulsifiers and gelling agents in food, pharmaceutical, paper, textile, and other industrial industries, in microbiology. A series of V. contain antibiotic. Substances, compounds that can derive salts of heavy metals from the body, radionuclides, which represents a certain interest for medicine. Some V. is an excellent object for genetic (acetabulary), biophysical and physiological (Harovaya V.) of studies. MN. V. mined by Prom. cultivation (see Aquaculture ). Science of algae - Algology , or ficology. See also Brown algae , Green algae , Red algae and etc.