Types of algae, their benefits for humans and application. Brown algae - flora of sea depths What is common in the structure of single-cellular and multicellular algae

12.03.2020 | Training

Who do not have a stem, root or foliage. Predominant the habitat of algae are seas and fresh reservoirs.

Department of green algae.

Green algae. There are unicellularand multicellularand contain chlorophyll. Green algae is multiplied by sexual and crucible type of breeding. Green algae live in water bodies (fresh and salty), in the soil, on the rocks and stones, on the bark of trees. The Green Algae Department has about 20,000 species and is divided into five classes:

1) Prococcal class - Unicellular and multicellular flavored forms.

2) Volvox class - The simplest single-celled algae, having flagella and capable of organizing colonies.

3) Head class - have a structure similar to the structure of the horsages.

4) Ulotrics class - have a layered nice or lamellar form.

5) Siphon class - The class of algae, externally similar to other algae, but consisting of one cell that has many cores. Siphon algae dimensions reach 1 meter.

Department of red algae (bugs).

Bagryans are found in warm seas At large depths. This department has about 4,000 species. Ledishchered algae has a dismembered structure, they are attached to the substrate with solesor ricoida. In the plastids of red algae contained chlorophyll, caratinoidsand fikobilins.

Another feature of red algae is that they multiply with complex interchange. Disputes and gamets of red algae Still, as they do not have flavors. The process of fertilization occurs passively by transferring men's weights to the genital organs of women's individuals.

Division of brown algae.

Brown algae. - These are multicellular organisms having a yellowish-brown color due to the concentration of carotene in surface layers of cells. There are about 1.5 thousand species of brown algae, which have a wide variety of forms: corrupt, plates, spherical, cortical, nitialoid.

Due to the content of gas bubbles in the layers of brown algae, most of them are capable of holding a vertical position. Cells of layers have differentiated functions: melting and photosynthetic. There is no full-fledged conductive system in brown algae, but in the center of the layer there are fabrics transporting products of assimilation. Nourishing mineral substances are absorbed by the entire surface of the layer.

Different types of algae breed all views of breeding:

Dispute;

Sexual (isogatural, monogamous, heterogamous);

Vegetative (found with random division of some parts of the layer).

The value of algae for the biosphere.

Algae are the initial link of the majority of food chains of various reservoirs, oceans and seas. Algae is saturated with oxygen atmosphere.

Seaweedactively are usedto obtain various products: Agar-Agar polysaccharides and carragegen used in cooking and cosmetics are extracted from red algae; Alginic acids, also used in the food and cosmetic industry, are extracted from brown algae.

The world ocean is a limitless source of amazing animals and plants, among which various algae occupy an important place. The report will be discussed about the representative of the marine flora - brown algae.

Types of brown algae

Brown seaweed - multicellular organisms. They live in sea water At a depth of 5 to 100 meters. Usually they are attached to the stones. The brown algae gives a special brown pigment. Some types of algae are amazed by their sizes, reaching a length of up to 60 meters, there are also very tiny representatives. In the World Ocean lives more 1000 species Buro-green algae.

From an extensive class of brown algae, you can select some interesting and useful species for a person.

1. Sargassy

Sargassovo Sea received its name, thanks to the cluster in his waters floating brown sea algae - sargassa. Huge masses of these algae they float on the surface of the water and form a solid carpet. Because of this feature of the brown algae in antiquity of Sargassovo, the sea had bad glory - it was believed that the ship could get confused in algae and could not swim further, and if the sailors climb into the water, to unravel the ship, they are confused and drown themselves.

In fact, legends and myths about Sargasso Sea are not true, because Sargasss are absolutely safe and do not interfere with the movement of ships.

Sargassy are used:

as a source of potassium;
the stems of these algae are food and a shelter for and their young.

2. FUCU

Other names are marine grapes, King Algae. Futin is common in almost all marine reservoirs of the Earth. It dwells at a small depth of small bushes with long leaves of a greenish-brown shade. Futin - that's the storehouse of vitamins and nutrients.

Used:

in medicine for the treatment and prevention of various diseases and strengthening immunity;
it helps to care for the skin and hair, is used as a slimming additive.

3. Laminaria

Another names of Laminaria - sea cabbage. Looks like a long stalk of a brown-green color with leaves. This algae in black, red, Japanese and other seas lives. The chemical composition of algae is rich in vitamins, minerals, amino acids. Use food Only 2 types of laminaria - Japanese and Sakharist.

Using:

Inedible grades are widely used in medicine.
Just like fus, laminaria is used in various diets as a natural appetite drop.
Laminaria contains special substances that are able to protect the human body from hazardous radiation irradiation.
Also, sea cabbage is used to treat cancer and leukemia.

With a constant use of laminaria, it is possible to reduce the level of cholesterol in the blood, to establish the work of the intestine, increase the protective properties of immunity, normalize the metabolism, to establish the work of nervous, blood and respiratory systems.

Brown algae - marine plants that are widely used in many areas of human activity.

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Algae play a huge role in the nature and life of a person. First, they are active participants in the cycle of substances in the natural environment (the simplest unicellular species).

Secondly, indispensable natural sources vital microelements (vitamins, minerals). They are also used in medicine, cosmetology, food industry and other industries.

It does not require complex conditions for their breeding, and they grow at a depth of several meters to 40-100.

Life cycles of algae have several stages of the flow - depending on the complexity of the structure. The same and with the abilities to multiply.

What are the types, groups, names, in which sea is carried out by breeding algae, photos and others interesting information - About this in this article.

Description

Algae, unlike plants, grow in aquatic environment (Although there are plants that live in a similar environment). There are also soil, rocky representatives.

Life in water has relative stability: the presence of fluid, constant illumination and temperature, as well as a number of other advantages. And as a result, each cell, which is part of Algae, identical to the rest. Therefore, these aqueous "plants" (conditional name) practically do not have some pronounced features in their appearance (except for some, more "highly developed").

Mostly algae live in coastal seas - rocky shores, less often - sand or pebbles. The maximum height on which the water "plants can also live is a bit wetted surfaces (an example of almost plankton-sargass), a minimum - a few meters deep (the example of deep-water - red).

There are such algae that live in tidal reservoirs of rocky surfaces. But such varieties of maritime residents must withstand the lack of moisture, the temperature variable and the degree of salinity.

Algae are used in medicine, agronomy (soil fertilizer), food production for humans, industry and so on.

Body

Algae in their structure consist of one or multiple cells.

This is a single system that is layered at each other of the same type of cells. The dissection may be present here, but the presence of vegetative organs and other parts of the body of this water "plant" is excluded.

The appearance of algae is slightly similar to terrestrial non-timber plants.

The body of algae consists of:

layers (tall);
barrel (maybe or absent);
interstivers (for fasteners to surfaces - rocks, bottom, other similar plants);
trains.

Types of algae

There is a huge amount - from unicellular to complex (resembling higher plants). Sizes are also different - huge (up to 60 meters) and microscopic.

In total there are about 30,000 species of algae. They are divided into such departments:

sinegylase;
prochlorophyte;
cryptophyte;
red;
golden;
dinophite;
diatoms;
brown;
green;
yellow-green;
evglen;
harovy.

Also separation is carried out on such algae groups (according to the degree of complexity of the structure):

amebo-like (examples: golden, yellow-green, pyrophyte);
with a monad structure - unicellular, move through flames, some have an intracellular primitive structure (examples of algae: green, yellow-green, golden, eurlen, pyrophyte);
with a cocodic structure - unicellular, without any organoids, form colonies;
with palmello structure - a compound of several cocodic in total mass, have large sizes, attached to the substrate;
with a nice structure, these are already transients from the same multicellular algae, externally similar to the branched thread;
with a lamellar structure - multicellular, which are formed from threads that are combined with subsequent layering in various planes, forming a plate (there are single-layer and multi-layered);
with a siphonal structure, consist of a multi-core giant cell, similar to branching threads and balls.

Names and photos

Types of algae on images:

Unicellites - consist of a cell, nuclei and flagellas (bars). You can only see them under a microscope.
Multicolve - laminaries who are known to a person called "Sea Cabbage".

Life cycle

In algae, development occurs according to the cycle or cyclomorphosis (it depends on the complexity of the structure of the water "plant" and, accordingly, the method of reproduction).

Algae, not having (or having in exceptional cases), only the structure of the body changes due to development. The concept of cyclomorphosis is applicable to such aquatic plants (examples of algae: giella, blue-green, gelenodinium).

For cyclomorphosis, a high degree of plasticity is characteristic. The passage of steps depends largely on environmental conditions. There is no manifestation of strictly all stages of cyclomorphosis, some may "fall out" from the general sequence.

Strictly passing all the stages of the algae life cycle (in the scheme above) are exclusively in those aquatic plants that occupy the upper step of evolution (for example, brown).

Brown algae.

These are multicellular aqueous "plants" which belong to Okhrofitov. The name happened from the color of the pigment substance contained in chromatophoras: green (which means the ability to photosynthesis), as well as yellow, orange and brown, which, stirring, form a brownish shade.

Grow at depths 6-15 and 40-100 meters in all marine water bodies.

Brown algae, compared to the others, have a more complex structure: they have a similarity of organs and different tissues in the body.

The cell surfaces consist of a cellulose-and-student substance, which consists of proteins, salts, carbohydrates.

Each cage is algae there is kernel, chloroplasts (in the form of disks), nutrient (polysaccharide).

Life cycle of brown algae

This group of water "plants" distinguishes several types of growth: through the top or cell division.

Brown sex and most powerful ways. This means that some of them are recreated by fragmentation of their Taurus (Taloma), the formation of so-called kidneys or thanks to disputes.

Zospora have flavors and possess mobility. And also give Gametophyte, thanks to which sex cells are formed.

There are gamets derived from sporophyte and having an egg and spermatozoa in the haploid stage.

And these water "plants" emit pheromones, which contributes to the "meeting" of the male and female genital cells.

Thanks to all these processes, brown algae occurs alternating generations.

The use of brown algae

The most popular representative of this group is Laminaria, or "Sea Cabbage". This algae grows along the shores, forming thickets. As part of Laminaria, a large number of vital for the man of macro and trace elements, the most important of which is iodine. In addition to food, it is also used as a fertilizer for soil.

Also, brown algae are used in medicine and in the manufacture of cosmetics.

Characteristics of unicellular algae

These varieties of water "plants" are an independent system that can grow and develop, as well as self-reproduced.

In size, this microscopic size of algae (not visible to the naked eye), which can in fact be considered a "factory" for the extraction of useful raw materials: through the process of absorption from the environment of carbon dioxide and mineral salts, with subsequent processing of them in proteins, fats and carbohydrates.

Products of life support for single-cell algae are oxygen and carbon dioxide, which allows them to be active participants in the natural cycle.

Dilution of algae

Which seas are the most wide breeding of these marine "plants"? According to reference data, the maximum amount of algae is contained in the White Sea. On the shore there is a village of Reball (in the area of \u200b\u200bthe Solovetsky Island), where they are engaged in the mining and harvesting of these water gifts.

There are 2 types of brown algae: famous laminaria and fus ("marine grapes").

In addition to eating food, from these "plants" is made by biologically active substances that are used in medicine. These are very useful drugs, because they are environmentally friendly algae of the White Sea.

Such products reduce cholesterol in the blood, establish the work of the thyroid gland, prevent the development of age-related vessels associated with vessels, and so on. "Sea grapes" well apply when problems with varicose extension veins, cellulite, appearances of wrinkles.

Role in nature and human life

Algae is studied by specialized science - algology (or ficology), which is a section of botany.

The collection of information about these water "plants" is needed to solve such important tasks: wholebiological problems; economic tasks and so on.

This science is developing in the following directions:

The use of algae in medicine.
Use in solving environmental issues.
Accumulation of information on algae in order to solve other tasks.

These marine "plants" are currently living in natural water bodies and are grown on special farms.

Seaweed, as food and not only, popular in many countries of the world: Indonesia (annual collection of 3-10 million tons), Philippines, Japan, China, Korea, Thailand, Taiwan, Cambodia, Vietnam, Peru, Chile, England, USA ( California) and others.
The Philippines are currently opened new Product Nutrition - noodles of seaweed (contains calcium, magnesium, iodine).
Many favorite Japanese algae nori, which are dried with leaves and look square thin plates, applicable in the manufacture of sushi, rolls, for soups.
In Wales prepare popular lanoms of oats and red algae lan.
Food gelatin, additives, alginates are manufactured from algae (dressings, applied in dentistry).
The agar produced from these water "plants" is applied to the preparation of confectionery, desserts, beverages, meat dishes.
Algae concentrates are used in preparations to get rid of excess weight. Also included in the composition of toothpastes, cosmetics and paints.
Alginates are used in industry (paper coatings, paints, gels, glue, textile printing).

Summary

Types of algae (with photos), names, groups, breeding and use indicated in the article indicates that these are really important components of not only nature, but also many aspects of human life (health, beauty, industrial raw materials, food, and so on) . Without them, there would be no notorious "sea cabbage", marmalade, sushi and other such familiar dishes.

At first glance, it may seem that these simple natural "plants" are primitive (by their structure, vitality cycle) Algae, but in fact everything is different. It turns out that even these aqueous "plants" have sexual reproduction, the pheromones emit and maintain a circulation of substances in nature.

Seaweed (LAT. ALGAE) - a heterogeneous environmental group of predominantly phototrophic unicellular, colonial or multicellular organisms living, as a rule, in a water medium, which is a systematic relationship of many departments. When entering into symbiosis with mushrooms, these organisms during evolution formed completely new organisms - lichens.

The study of algae is an important step in the preparation of specialists in the field of mariculture, fish farming and maritime ecology. Science of algae is called algology.

Seaweed - a group of organisms of various origins combined by the following signs: the presence of chlorophyll and photoauthotrophic nutrition; In multicellular - the lack of a clear differentiation of the body (called the layer, or talomom) to the organs; lack of a pronounced conductive system; Habitat in aquatic environment or in wet conditions (in the soil, raw places, etc.). They themselves do not have organs, tissues and are deprived of a coating shell.

Some algae are capable of heterotrophy (powered by a finished organody), as an examined (cell surface), such as flagende, and swallowing through cellular mouth (evglen, dinofite). The sizes of algae fluctuate from the shares of the micron (kokkolitoforids and some diatoms) to 30-50 m (brown algae - laminaria, macrocystis, sargassum). Talloma is like unicellular and multicellular. Among the multicellular algae, along with large, there are microscopic (for example, the sporophyte of laminarium). There are colonial forms among unicellites when individual cells are closely related to each other (connected through plasmodesma or immersed in general mucus).

Algae includes a different number (depending on the classification) of eukaryotes, many of which are not related to general origin. Also to algae often include syine-green algae or cyanobacteria, which are prokarytami. Traditionally, algae is counted for plants.

Algae cells (with the exception of amosoboid type) are covered with a cellular wall and / or cellular shell. The wall is located outside the cell membrane, usually contains a structural component (for example, cellulose) and amorphous matrix (for example, pectin or agar substances); It may also include additional layers (for example, a spritten layer in Chlorella). The cell shell is either an outer silicone armor (in diatoms and some other ocher), or a compacted top layer of the cytoplasm (plasmamber), in which there may be additional structures, for example, bubbles, empty or cellulosic plates (peculiar shell, tenoflagellates ). If the plastic cell shell can be capable of a so-called metabolic movement - slide due to a small change in the body shape.

Photosyntheses (and "masking" them) pigments are located in special plaststs - chloroplasts. Chloroplast has two (red, green, rigorous algae), three (eurlennas, dinoflates) or four (oxphite algae) membranes. It also has its own strongly reduced genetic apparatus, which suggests its symbogenesis (the origin from the captured pulp or, in heterobonte algae, eukaryotic cell). The inner membrane is protruding inside, forming folds - thylakoids, assembled in stacks - marriage: monotylacoidal in red and blue-green, two- and more in green and kharov, trothylacoidal in the rest. On tylacoids, in fact, pigments are located. Chloroplasts in algae have various shapes (Small disco, spiral-shaped, cupid, stars, etc.). Many in chloroplast have dense education - Pyrenoids.

Photosynthesis products, in this moment Unnecessary, persists in the form of various spares: starch, glycogen, other polysaccharides, lipids. In addition to the lipid, being lighter than water, allow you to stay on the plankton diatom plan with their heavy shell. In some algae, gas bubbles are formed, also providing algae lifting force.

Algae has vegetative, cull and sexual reproduction.

Large seaweed, mostly brown, form whole underwater forests often. Most algae lives from the surface of the water to a depth of 20-40 m, single species (from red and brown) with good water transparency descend to 200 m.

In 1984, the colarin red algae was found at a depth of 268 m, which is a record for photosynthetic organisms. Algae is often B. large quantities They live on the surface and in the upper layers of the soil, one of them absorb atmospheric nitrogen, others adapted to life on the bark of trees, fences, walls of houses, rocks.

Microscopic algae cause red or yellow "staining" snow high in the mountains and in polar areas. Some algae take into symbiotic relationships with mushrooms (lichens) and animals.

Algae - an extremely heterogeneous group of organisms, numbering about 100 thousand (and according to some data up to 100 thousand species only in the composition of the diatom) species. Based on the differences in the set of pigments, the structure of the chromatofor, the peculiarities of morphology and biochemistry (the composition of the cellular shells, the types of spare nutrients), with a majority of domestic systematics, 11 algae departments are distinguished.

Of the brown algae, many useful substances used in the production of plastics, varnishes, paints, paper and even explosives are obtained. Of them make medicines (including iodine), fertilizer, feeding for livestock. Algae occupy an important place in the menu of peoples South-East AsiaBeing the basis of a set of dishes.

The Red Sea is named so because of the abundance of oscillation - algae of red. Although it contains a red pigment, it applies to the separation of blue-green algae.

From the red algae of euheums, the carrageage substance is mined for the manufacture of lipstick and ... ice cream.

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The department of organisms, considered here as algae, is very diverse and does not represent a single taxon. These organisms are inhomogeneous in their structure and origin.

Algae - autotrophic plants, in their cells there are various modifications of chlorophyll and other pigments that provide photosynthesis. Algae dwells in fresh and sea, as well as on land, on the surface and thicker than the soil, on the bark of trees, stones and other substrates.

Algae belong to 10 divisions of two kingdoms: 1) blue-green, 2) red, 3) pyrophyte, 4) golden, 5) diatoms, 6) yellow-green, 7) brown, 8) Evglen, 9) green and 10 ) Harov. The first department refers to the kingdom of prokaryotes, the rest - to the kingdom of plants.

Sine-green algae, or cyanobacteria (Cyanophyta)

There are about 2 thousand species united by about 150 genera. These are the most ancient organisms, traces of the existence of which are found in the Precambrian sediments, their age is about 3 billion years.

Among the blue-green algae there are unicellular forms, but most species are colonial and nichly organisms. They differ from other algae in that there is no decorated kernel in their cells. They lack mitochondria, vacuoles with cellular juice, no plastid plates, and pigments, with which photosynthesis is carried out, are in photosynthetic plates - lamellah. Pigments of blue-green algae are very diverse: chlorophyll, carotes, xanthophylls, as well as specific pigments from the Ficobiline Group - Blue Ficotianin and Red Ficoerytrin, found besides cyanobacteria only in red algae. The color of these organisms is most often blue-green. However, depending on the quantitative ratio of various pigments, the color of these algae may be not only blue-green, but also purple, reddish, yellow, pale blue or almost black.

Sine-green algae are common throughout the globe and are found in a wide variety of conditions. They are able to exist even in extreme habitat conditions. These organisms endure long dimming and anaerobiosis, can live in caves, in different soils, in the hydrogen sulfide layers of natural sludge, V.Termal waters, etc.

Around the cells of colonial and nichly algae are formed mucous vagina, which serve as a protective overturn, protecting cells from drying and being a light filter.

Many nice blue-green algae have peculiar cells - heterocysts. These cells are well expressed a two-layer sheath, and they look empty. But these are live cells filled with transparent content. Sine-green algae having heterocysts can fix atmospheric nitrogen. Some types of blue-green algae are components of lichens. They may be as symbiountes in the tissues and organs of higher plants. Their ability to fix atmospheric nitrogen is used by higher plants.

The mass development of blue-green algae in reservoirs may have negative consequences. Increased and pollution of water with organic substances cause the so-called "water bloom". This makes water unsuitable for human use. Some freshwater cyanobacteria are toxic for humans and animals.

The reproduction of blue-green algae is very primitive. Unicellular and many colonial forms multiply only cell division in half. Most of the nichly forms are multiplied with hormagonia (these are short sections that separated from the maternal thread growing into adult individuals). The reproduction can be carried out and with the help of a spore - born thick-walled cells capable of experiencing unfavorable conditions and then germinate into new threads.

Department of red algae (or bugs) (rhodophyta)

Red algae () - numerous (about 3,800 species of more than 600 genera) Group mainly marine inhabitants. Their sizes range from microscopic to 1-2 m. Externally red algae are very diverse: there are filamentary, lamellar, coral-like forms, in varying degrees dissected and branched.

Red algae have a peculiar set of pigments: In addition to chlorophyll A and B, there is chlorophyll D, known only for this group of plants, there are carotes, xanthophylls, as well as pigments from the Fikobilin Group: Blue pigment - Ficotianin, red - ficoeroidrin. A different combination of these pigments determines the color of algae - from bright red to bluish-green and yellow.

Red algae breeding vegetative, intimate and sexually multiplies. Vegetative reproduction is characteristic only for the lowest organized bugs (single-cellular and colonial shapes). In highly organized multicellular forms, the tald tall sections die. For crucible reproduction serve various kinds of disputes.

Sex progestion process. On the Gametophyt plant, men's and female sex cells (gamets) are formed, devoid of flavors. For fertilization women's Gamets. Do not go out environment, and remain on the plant; Male gamets are thrown out and passively tolerated water currents.

Diploid plants - sporophytes - have the same appearancelike Gametophytes (haploid plants). This is an isomorphic change of generations. In spores are formed by the bodies of the useless reproduction.

Many red algae are widely used by man, they are edible and helpful. The food and medical industry is widely used different species The bugs (about 30) polysaccharide agar.

Department of pyrophyte (or dinophyte) algae (Pyrrophyta (Dinophyta))

The department consists of about 1,200 species of 120 genera, unifying eukaryotic single-cellular (including windmill), cocoid and nichly shapes. The group combines signs of plants and animals: some species have tentacles, pseudopodia and cutting cells; Some have a nutrhess characteristic of animals. Many have stigma, or eyes. Cells are often covered with hard shell. Chromatophores of brown and reddish shades, contain chlorophylls A and C, as well as carotes, xanthophylls (sometimes - Ficotian and FicoErytrin). Starch is postponed as spares, sometimes oil. Slabcomer cells have a clearly pronounced spinal and abdominal sides. On the cell surface and in the throat there are grooves.

We multiply dividing in a movable or immobile condition (vegetatively), zoospores and cargoes. Sexual reproduction is known in a few forms; It passes in the form of a merger isogmet.

Pyroocyte algae is the usual inhabitants of contaminated water bodies: ponds, sumps, some reservoirs and lakes. Many form phytoplankton in the seas. Under adverse conditions, cysts with thick cellulose shells are formed.

Cryptomonas (Cryptomonas) is most widespread and rich in species.

Department Golden Algae (Chrysophyta)

Microscopic or small (up to 2 cm length) golden-yellow organisms, living in saline and fresh reservoirs throughout the globe. There are unicellular, colonial and multicellular forms. Russia knows about 300 species of 70 clans. Chromatophores are usually golden yellow or brown. They contain chlorophylls A and C, as well as carotenoids and fucoxanthin. Chrysolineartarin and oil is deposited as spares. Some types of heterotrophna. Most of the forms have 1-2 flashes and, by virtue of this mobile. Multiply predominantly for use - division or zoospores; Several process is known only in several species. It is usually found in clean fresh waters (sour waters of sphagnum swamps), less often - in the seas and soils. Typical phytoplankton.

Diatomal Diatoma Department (Bacillariophyta (Diatomea))

Diatoms of algae (diatoms) are about 10 thousand species relating to about 300 births. These are microscopic organisms that live mainly in water bodies. Diatoms of algae are a special group of single-celled organisms other than other algae. Diatom cells are covered with silica. In the cell there are vacuoles with cellular juice. In the center there is a kernel. Chromatophores are large. The color of them has various shades of yellow-brown color, as carotenes and xantophylls, having yellow and brown shades, are dominated among pigments, having yellow and brown shades, and masking chlorophylls a and c.

For diatom shells, the geometric correctness of the structure and a large variety of outlines are characteristic. The shell consists of two halves. Large - epitec - covers a smaller - hypotension, like the cover covers the box.

Most diatoms having double-sided symmetry are capable of moving along the surface of the substrate. Movement is carried out using the so-called seam. The seam is a slit, cutting the wall of the sash. The movement of the cytoplasm in the slit and friction of it about the substrate ensure the movement of the cell. The cells of diatoms having radial symmetry are not capable of moving.

Diatoms typically multiply cell division into two halves. Protoplast increases in volume, as a result of which the epithek and hypothepa diverge. Protoplast is divided into two equal parts, the core is mittoically divided. In each half of the separated cell, the shell plays the role of epitecia and completes the missing half of the shell, always hypotension. As a result of numerous divisions, there is a gradual decrease in the size of the cells in part of the population. Some cells are about three times less compared to the initial. Reached minimum sizes, cells develop auxospore ("growing disputes"). The formation of auxospore is associated with a sexual process.

Diastomy algae cells in vegetative state diploid. Before sexual reproduction there is a reduction core division (MEIOS). Two diatom cells come closer, the sash are moved, the haploid (after meiosis) the kernels are merged, and one or two auxospores are formed. Auxospore grows some time, and then produces a shell and turns into a vegetative individual.

Among the diatoms there are light-minded and imaging species, they live in reservoirs at different depths. Diatoms can dwell in soils, especially wet and wetlands. Along with other algae diatoms can cause "blooming" snow.

The diatoms play a big role in the economy of nature. They serve as a constant feed base and initial link in food chains for many aquatic organisms. They eat many fish, especially young.

Diatomatic shells, deposited on the bottom for millions of years, form a sedimentary geological rock - diatomitis. It is widely used as construction material with high heat and sound insulation properties, as filters in the food, chemical, medical industry.

Department of yellow-green algae (Xanthophyta)

This algae group has about 550 species. These are mainly inhabitants of freshwater, less common in the seas and on wet soil. Among them are single-cellular and multicellular forms, flaky, cocoid, nitrate and lamellar, as well as siphon organisms. For these algae, yellow-green painting is characterized, which gives the name to the whole group. Chloroplasts of discoid form. Characteristic pigments - chlorophylls A and C, A and B carotenoids, Xantofilla. Spare substances are glucan ,. Sexual reproduction is oogan and isochny. Vegetatively breeds division; Miscellaneous reproduction is carried out by specialized moving or stationary cells - zoo- and aplane.

Division of brown algae (Phaeophyta)

Brown algae - high-organized multicellular organisms living in the seas. There are about 1500 species of about 250 types. The largest of the brown algae reaches several tens of meters (up to 60 m) of length. However, this group also encounters microscopic sizes. The shape of the layer can be very diverse.

The overall sign of all algae belonging to this group is yellowish-brown painting. It is caused by carotene and xanthophille pigments (Fukoxanthin et al.), Which mask the green color of chlorophylls a and c. Cellular cellulosic cellular shell with an outer pectin layer capable of strong ease.

In the brown algae there are all forms of breeding: vegetative, cull and sex. Vegetative reproduction occurs by separable parts of the layer. Miscellaneous reproduction is carried out with zoospore (moving thanks to the spore flagella). The sexual process in brown algae is represented by the isogram (less often anisogamy and oogami).

Many brown algae, Gametophyte and spores differ in shape, size and structure. In the brown algae there is an alternation of generations, or changing the nuclear phases in the development cycle. Brown algae are found in all seas of the globe. In thickets of brown algae near the shores, shelter, places of reproduction and nutrition are found numerous coastal animals. Brown algae are widely used by man. Of these, alginates (alginic acid salts) are obtained, used as stabilizers of solutions and suspensions in the food industry. They are used in the manufacture of plastics, lubricants, etc. Some brown algae (laminaries, alaria, etc.) are used in food.

Department of Evglen Algae (Euglenophyta)

In this group, about 900 species of about 40 gods. These are unicellular harness, mostly freshwater inhabitants. In chloroplasts there are chlorophylls A and B and a large group of auxiliary pigments from the carotenoid group. These algae, photosynthesis occurs in the light, and they go to heterotrophic nutrition in the dark.

The reproduction of these algae occurs only by the mitotic division of the cell. Mitosis differs from this process in other groups of organisms.

Section Green Algae (Chlorophyta)

Green algae is the largest algae, numbering, according to various estimates, from 13 to 20 thousand species of about 400 genera. For these algae, a purely green is characteristic of the highest plants, painting, since chlorophyll dominates among pigments. In chloroplasts (chromatophoras) there are two modifications of chlorophyll A and B, as in higher plants, as well as other pigments - carotes and xantophylls.

The rigid cell walls of green algae are formed by cellulose and pectin substances. Spare substances - starch, less often oil. Many features of the structure and life of green algae testify to their relationship with higher plants. Green algae differ in the greatest compared to other divisions of the manifold. They can be unicellular, colonial, multicellular. This group presents all the diversity of the morphological differentiation of the body, known for algae, is a monad, cocked, palmello, nichtage, lamellar, non-cellular (siphonal). The range of their sizes is large - from microscopic single cells to large multicellular forms in tens of centimeters. Reproduction is vegetative, cull and sex. All major types of development forms are found.

Green algae dwells more often in fresh reservoirs, but there are many solon-water and marine forms, as well as the immediate terrestrial and soil species.

The class of volvoxes includes the most primitive representatives of green algae. It is usually unicellular organisms with flagellas, sometimes combined into a colony. They are moving throughout life. Completed in shallow fresh reservoirs, swamps, in the soil. The types of chlamdomonad species are widely represented from unicellular. Chalamic or ellipsoidal chlamdonad cells are covered with a shell consisting of hemicellulose and pectin substances. At the front end of the cell there are two flagellas. All interior Cells occupy a cup-shaped chloroplastic. In the cytoplasm that fills the cup-shaped chloroplastic, the kernel is located. The base of flagellas has two pulsating vacuoles.

Miscellaneous reproduction occurs with the help of windmill zoospore. When sexually reproduction in chlamdonad cells are formed (after meiosis) windmakes.

For types of chlamdomanade, characteristic iso-, hetero- and oogami. Upon the occurrence of unfavorable conditions (drying out of the reservoir), chlamdonad cells lose flare flashes, covered with a mucous membrane and multiply division. With the occurrence of favorable conditions, they form flagella and move to a moving lifestyle.

Along with the autotrophic power supply (photosynthesis), chlamdonad cells are capable of sucking through the shell dissolved organic substances, which contributes to the processes of self-purification of polluted water.

Cells of colonial forms (Pandorin, Volvoks) are built by type chlamdonad.

In the class of the transfers, the main form of the vegetative body is fixed cells with a dense shell and a colony of such cells. Examples of single-cellular transfers can serve as chlorococcal and chlorella. Caplerate reproduction of chlorococcal is carried out with the help of beo-making movable zoospores, and the sexual process is a fusion of mobile windmill isogumet (isogamy). In Chlorella, there are no mobile stages with a bunch of reproduction, the sexual process is missing.

The Ulotrics class combines the nitrate and lamellar forms living in fresh and marine reservoirs. Ulotrix is \u200b\u200ba thread of up to 10 cm long attached to underwater subjects. Thread cells are identical, short-cylindrical with plate charged by chloroplasts (chromatophoras). Miscellaneous reproduction is carried out by zoorbra (moving cells with four flagellas).

Sex process isochny. Gamets are movable due to the presence of two flagellas in each gamete.

The class of conjugates (linkage) combines unicellular and nichly shapes with a peculiar type of sexual process - conjugation. Chloroplasts (chromatophores) in the cells of these algae of the plate type and are very diverse in shape. In ponds and in reservoirs with a slow flow, the bulk of the green of the tire form the nice forms (spirohyder, zigneum, etc.).

When conjugation from the opposite cells of the two numbered, the threads grow processes that form the channel. The contents of the two cells are drained, and the zygota is formed covering the thick shell. After the time of resting the zygota germinates, giving the beginning with new nichly organisms.

The siphon class includes algae with the non-tossy structure of the layer (Taloma) during its fairly large sizes and complex dismemberment. Sea siphon algae Cowlerpa externally resembles a leafy plant: its size is about 0.5 m, it is attached to the ground with rhizoids, its layers are raised along the ground, and vertical formations resembling leaves contain chloroplasts. It easily multiplies vegetatively parts of the layer. In the body of algae there are no cell walls, it has a solid protoplasm with numerous nuclei, chloroplasts are located near the walls.

Department Harovy Algae (Charophyta)

This is the most difficult arranged algae: their body is differentiated to nodes and interstices, in the nodes - a flutter of short branches resembling leaves. Plant size from 20-30 cm to 1-2 m. They form solid thickets in fresh or weakly salted water bodies, attaching to the ground with rhizoids. Outwardly, they resemble higher plants. However, there is no real dismemberment of the root, stem and leaves from these algae. Harov algae has about 300 species belonging to 7 genera. They have similarities with green algae in the composition of the pigments, the structure of cells, the peculiarities of the reproduction. There is similarity and with higher plants in the peculiarities of the reproduction (oogami), etc. The noteworthy similarity indicates the presence of a common ancestor in the Harov and higher plants.

The vegetative reproduction of the Harov is carried out by special structures, the so-called non-rhymers formed on the rhizoids and on the lower parts of the stems. Each of the muscles will easily germinate, forming a proton, and then the whole plant.

The entire algae department after the first dating with him to embrace mentally and give each department its right place in the system is very difficult. The algae system has been developed in science not soon and only after many unsuccessful attempts. Currently, we place any system that the main requirement is that it be phylogenetic. At first they thought that such a system could be very simple; They represented it in the form of one pedigree, at least with many side branches. Now we build it out of otherwise, as in the form of many pedigree lines, developing in parallel. The case is also complicated by the fact that on a number of progressive changes, there are also regressive, which put a difficult task for permission - in the absence of one or another sign or a body, to decide that he has not yet appeared or has already disappeared?

The most perfect was considered a long system given by Villa in 236 issuing the main essay on the descriptive systematics of plants, which emerges under the editors of A. Egerler. The main group here recognize flagellas or Flagellata.

This scheme encloses only the main group of green algae. For the rest, take the scheme of the Rosen, changing only the names of the groups, according to the above when they are described.