Vital activity and structure of algae. Features of the structure of algae

How beautiful and amazing the underwater world is, so much he is mysterious. Until now, scientists are discovering some completely new, unusual animal species, exploring the incredible properties of plants, expanding the areas of their application.

The vegetative world of oceans, seas, rivers, lakes and marshes is not as diverse as terrestrial, but it is also unique and beautiful. We will try to understand what these amazing underwater plants are, what is the structure of algae and their significance in the life of man and other living beings.

Systematic position in the system of organic world

By common standards, algae are considered a group of lower plants. They are part of the Empire Cellular kingdoms. Plants and sub-kingdoms. Lower plants. In fact, such a division is based precisely on the features of the structure of the representatives' data.

They got their name for being able to grow and live under water. The Latin name is Algae. Hence, the name of the science that deals with the detailed study of these organisms, their economic significance and structure, is formed - algology.

Classification of algae

Modern data allow to attribute all available information about different types of representatives to ten divisions. The basis of the separation is the structure and life activity of algae.

1. Blue-green unicellular, or cyanobacteria. Representatives: cyanogen, ruffian, microcystis and others.
2. Diatoms. These include pinurnaria, navicula, pleurosigma, melozira, gomponema, sine, and others.
3. The golden ones. Representatives: chrysodendron, chromulin, and other.
4. Porphyry. These include porphyry.
5. Brown. Laminaria, sargassum, cystoseira and others.
6. Yellow-green. This includes such classes as Xanthropods, Xanthococcus, Xanthomonas.
7. The Reds. Gracillaria, Anfeltsia, Crimson.
8. Green. Chlamydomonada, wolvox, chlorella and others.
9. The Elusive. These include the most primitive representatives of the Greens.
10. Charovye. Hara as the main representative.

This classification does not reflect the structure of algae, but only shows their ability to photosynthesize at different depths, showing pigmentation of a particular color. That is, the coloring of the plant is the sign by which it is attributed to this or that department.

Algae: Features of the structure

Their main distinguishing feature is that the body is not differentiated into parts. That is, algae do not, as in higher plants, have a clear division into an escape, consisting of a stem, leaves and a flower, and a root system. The structure of the body of algae is represented by a thallus, or thallus.

In addition, the root system is also absent. Instead of it there are special semi-transparent thin thread-like processes, called rhizoids. They function as an attachment to the substrate, acting as if they were suckers.

Thallum itself can be very diverse in form and color. Sometimes some representatives strongly resemble the escape of higher plants. Thus, the structure of algae is very specific for each department, so in the future it will be considered in more detail by examples of the corresponding representatives.

Types of thalli

Thallus is the main distinguishing feature of any multicellular algae. The peculiarities of the structure of this organ consist in the fact that thallus can be of various types.

1. Amoeboid.
2. Monad.
3. Capsular.
4. The crocoid.
5. Filamentous, or trinitarian.
6. Sarcinoid.
7. False tissue.
8. Siphonic.
9. Pseudoparenchymal.

The first three are most typical for colonial and unicellular forms, the rest for more advanced, multicellular, complex in organization.

This classification is only approximate, since each type has transitional variants, and then it is practically impossible to distinguish one from another. The facet of differentiation is erased.

Cage of algae, its structure

The peculiarity of these plants is initially in the structure of their cells. It is somewhat different from that of higher representatives. It is possible to identify several main points by which cells are excreted.

1. In some individuals they contain specialized structures of animal origin - organelles of movement (flagella).
2. Sometimes stigma occurs.
3. Shells are not quite the same as in a normal plant cell. Often they are provided with additional carbohydrate or lipid layers.
4. Pigments are enclosed in a specialized organ - chromatograph.

In other respects, the structure of the algal cell obeys the general rules of this in higher plants. They also have:

• Nucleus and chromatin;
• Chloroplasts, chromoplasts and other pigment-containing structures;
• Vacuoles with cell sap;
• A cell wall;
• Mitochondria, lysosomes, ribosomes;
• Golgi apparatus, endoplasmic reticulum and other elements.

In this case, the cellular structure of unicellular algae corresponds to that of prokaryotic creatures. That is, there are also no nucleus, chloroplasts, mitochondria and some other structures.

The cellular structure of multicellular algae fully corresponds to that of higher terrestrial plants, with the exception of certain species features.

Department of Green Seaweed: a structure

This department includes the following types:

• Single-celled;
• Multicellular;
• Colonial.

In total, there are more than thirteen thousand species. Main classes:

• Volvtosovye.
• Conjugates.
• Ulotriksovye.
• Siphonic.
• Protococcal.

Features of the structure of unicellular cells consist in the fact that outside the cell is often covered with an additional shell, which performs the function of a peculiar skeleton, a pellicle. This allows it to be protected from external influences, to keep a certain shape, and also over time to form on the surface beautiful and amazing patterns of metal ions and salts.

Typically, the structure of green algae unicellular type necessarily includes some organoid movement, most often a flagella at the back end of the body. A spare nutrient is starch, butter or flour. The main representatives: chlorella, chlamydomonada, volvox, chlorococcus, protocaccus.

Very interesting are representatives of siphon, such as kaulerpa, codum, acetobularia. Their thallus is not a filamentous or lamellar type, but one giant cell that performs all the basic functions of vital activity.

Multicellular cells may be lamellar or filamentous. When it comes to lamellar forms, they are often multilayered, not just single-layered. Often, the structure of algae of this type is very similar to shoots of higher terrestrial plants. The more branched the tall, the more similar.

The main representatives are the following classes:

• Ulotriksovye - ulotriks, ulva, monostroma.
• Couples, or conjugates - zygonema, spirogyra, muziotiya.

Colonial forms are special. The structure of green algae of this type consists in a close interaction between a large cluster of unicellular representatives, united, as a rule, by mucus in the external environment. The main representatives can be considered volvoksov, protokokkovyh.

Features of life activity

The main habitats are fresh water bodies and seas, oceans. Often cause the so-called flowering of water, covering itself with its entire surface. Chlorella is widely used in cattle breeding, as it purifies and enriches oxygen with water, and the dry residue goes to feed cattle.

Unicellular green algae can be used in spacecraft to produce oxygen as a result of photosynthesis without changing its structure and death. According to the time interval, this department is the oldest in the history of underwater plants.

Department of Red Algae

Another name for the department is Bagrianka. It appeared because of the special color of the representatives of this group of plants. It's pigments. The structure of red alga as a whole satisfies all the basic features of the structure of lower plants. They can also be unicellular and multicellular, they have a variety of tall. There are both large and extremely small representatives.

However, their coloration is due to certain features - along with chlorophyll these algae have a number of other pigments:

• Carotenoids;
• Phycobilins.

They mask the main green pigment, so the color of plants can range from yellow to bright red and crimson. This is due to the absorption of virtually all wavelengths of visible light. The main representatives: anfeltia, phyllophora, gracilia, porphyry and others.

Meaning and way of life

Capable of dwelling in freshwater, but most are still marine representatives. The structure of red algae, and specifically the ability to produce a special substance agar-agar, makes it possible to widely use it in everyday life. Especially it concerns the food confectionery industry. Also, a significant proportion of individuals are used in medicine and are directly used by people for food.

Department of Algae: structure

Often, within the framework of the school program for studying lower plants, their various departments, the teacher asks the students: "List the features of the structure of brown algae." The answer is this: thallus has the most complex structure of all known individuals of lower plants, within the thallus, which is often of impressive size, with conductive vessels; Thall itself has a multi-layered structure, which is why it resembles the tissue type of the device of higher terrestrial plants.

The cells of representatives of these algae produce a special mucus, so the outside is always covered with a kind of layer. Spare nutrients are:

• Carbohydrate laminar;
• Oils (fats of different types);
• Mannitol alcohol.

That's what you need to say, if you are asked: "List the features of the structure of brown algae." They are actually many, and they are unique against the background of other representatives of underwater plants.

Use in the household and distribution

Brown algae - the main source of organic compounds, not only for marine herbivores, but also for people living in the coastal zone. Their use in food is widespread among different peoples of the world. Of them, medicines are made, flour and minerals, alginic acids are obtained.