how beautiful and amazing underwater world, just as he is mysterious.Until now, scientists discover some completely new, unusual species, studied the incredible properties of plants, expanding the field of application.
flora of the oceans, seas, rivers, lakes and swamps are not as diverse as the land, but also unique and beautiful.We will try to find out what are these amazing underwater plants, algae, and what is the structure of their value in the lives of humans and other living beings.
Systematic position in the organic world
According to generally accepted standards of algae are considered a group of lower plants.They are part of the empire Cell kingdom Plants subkingdoms Lower plants.In fact, this division is based on the features of the structure of these representatives.
The name they got for being able to grow up and live under water.Latin name - Algae.Hence the name of science is formed and engaged in a detailed study of these organisms, their economic importance and structure, - phycology.
Classification algae
Current data allow to carry all the information about the different types of representatives of ten departments.The basis of the separation of structure and put the livelihoods of algae.
- Blue-green unicellular, or cyanobacteria.Representatives: cyan, Monera, mikrotsistisy and others.
- Diatoms.These include pinnulyariya, naviculae, plevrosigma, melozira, gomfonema, sinedra and others.
- Golden.Representatives hrizodendron, hromulina, primnezium and others.
- Porphyry.These include the porphyry.
- Brown.Kelp, Sargassum, cystoseira and others.
- yellow-green.These include classes such as Ksantopodovye, Ksantokokkovye, Ksantomonadovye.
- Red.Gratsillyariya, ahnfeltia, whelk.
- Green.Chlamydomonas, Volvox, chlorella and others.
- Evshenovye.They are the most primitive representatives of the green.
- Stoneworts.Hara as the main representative.
This classification does not reflect the structure of algae, and only shows their ability to photosynthesize at different depths, showing the pigmentation of a particular color.That is, the color of the plant is the ground on which it belongs to a particular department.
Algae: structural features
Their main distinguishing feature - is that the body is not differentiated into parts.That is, there is no algae, like higher plants, a clear division of escape, which consists of the stem, leaf and flower, and root system.Build algae represented thallus or thallus.
In addition, the root system is also available.Instead, in the presence of a special translucent thin thread-like appendages called rhizoids.They perform the function of attachment to the substrate, thus acting like a suction cup.
Himself metal may be very different shapes and colors.Sometimes some representatives strongly reminiscent of the escape of higher plants.Thus, the structure of algae is very specific for each department, so in the future will be discussed in more detail on the examples of the representatives concerned.
types thalli
Thallus - the main feature of any multicellular algae.Features of the structure of this body lies in the fact that the metal may be of different types.
- ameboid.
- monadic.
- Kapsalny.
- coccoid.
- filamentous or trihalny.
- Sartsinoidny.
- Lozhnotkanevy.
- siphon.
- Psevdoparenhimatozny.
first three most characteristic of the colonial and unicellular forms, the other for the better, multicellular, complicated organization.
This classification is only approximate, because each type of transitional options are available, and then to distinguish one from another is almost impossible.Fringe differentiation erased.
cell algae, its structure
feature of these plants is initially in the structure of their cell.It is somewhat different from that of the highest representatives.You can mark several key points on which the cells were isolated.
- Some species they contain specialized structures of animal origin - the organelle movement (flagella).
- Sometimes there is a stigma.
- Skins not quite the same as a conventional plant cell.They are often equipped with additional carbohydrate or lipid layers.
- pigments enclosed in a specialized body - chromatophores.
The rest of the structure of the cells of algae is subject to the general rules of that of the higher plants.They also have:
- nucleus and chromatin;
- chloroplasts, chromoplasts and other pigment-containing structures;
- vacuole with cell sap;
- cell wall;
- mitochondria, lysosomes, ribosomes;
- Golgi apparatus, endoplasmic reticulum, and other elements.
This cellular structure corresponds to that of unicellular algae have prokaryotic beings.That is also no nucleus, chloroplasts, mitochondria, and some other structure.
cellular structure of multicellular algae completely corresponds to that of higher terrestrial plants, except for certain specific features.
Division Green algae: structure
In the department include the following:
- celled;
- multicellular;
- colonial.
all there are more than thirteen thousand species.The main classes:
- volvoxes.
- conjugates.
- Ulotriksovye.
- siphon.
- protococcal.
avilable unicellular lies in the fact that outside of the cell is often covered by additional coating serving as a kind of skeleton - pellicle.This allows it to be protected from external influences, to keep a certain shape and with time on the surface to form a beautiful and surprising patterns of metal ions and salts.
As a rule, the structure of a single-celled green algae such as a mandatory element of any organelle movement, often flagellum at the rear end of the body.Spare nutrient - starch, oil or flour.Key representatives: Chlorella, Chlamydomonas Volvox, hlorokokkum, protokokkus.
very interesting representatives of the siphon such as Caulerpa, kodium, atsetobulyariya.Their thallium - it's not stranded and plate type, and one giant cell that performs all the basic functions of life.
Multicellular may have lamellar structure, or filamentous.If it is a plate-like shape, that often they are layered, and not only monolayer.Often, this kind of structure of algae is very similar to the shoots of higher terrestrial plants.The more branches thallium, the greater the similarity.
main representatives - the following classes:
- Ulotriksovye - ulothrix, Ulvi, monostroma.
- Stseplyanki or conjugates - zigonema, Spirogyra, muzhotsiya.
colonial forms - special.The structure of green algae of this type is closely interconnected with large concentrations of unicellular representatives of united, as a rule, with mucus in the external environment.The main representatives can be regarded as Volvox, protococcal.
Features livelihoods
main habitats - is fresh water and the sea, the oceans.Often the cause so-called algal blooms, are clouding its entire surface.Chlorella is widely used in animal husbandry as cleans and oxygenates the water, and the dry residue is fed to livestock.
unicellular green algae can be used in space vehicles for the production of oxygen by photosynthesis without changing its structure and death.At a time warp is the Department - the oldest in the history of underwater plants.
Division Red algae
Other department name - whelk.It appeared because of the special colors of this group of plants.The thing pigments.The structure of the red algae as a whole fulfills all the basic features of the structure of lower plants.They may also be unicellular and multicellular have thallus of various types.There are both large and extremely small representatives.
However, their coloration due to certain features - along with chlorophyll, these algae have a number of other pigments:
- carotenoids;
- phycobilins.
They mask the principal green pigment, so the color of plants vary from yellow to bright red and crimson.This occurs due to absorption of substantially all wavelengths of visible light.Key representatives: ahnfeltia, phyllophora, gracilaria, porphyry and others.
value and lifestyle
Able to inhabit fresh water, but most - yet marine representatives.The structure of the red algae, namely the ability to produce a special substance agar, makes extensive use of it in everyday life.This is especially true of food confectionery industry.Also, a significant portion of individuals is used in medicine and is used directly by people for food.
Department Kelp: structure
Often in the school curriculum the study of lower plants, their different parts of the teacher asks the students: "List the structural features of the kelp."The answer is: thallium has the most complicated structure of all known species of lower plants, in the thallus, which is often impressive size, arranged conductive vessels;he has a multilayer structure of thallium, because of what resembles a fabric device type of higher terrestrial plants.
cells are representatives of these algae produce a special mucus, so the outside is always covered with a layer of a kind.Reserve nutrients are:
- carbohydrate kelp;
- oils (oils of different types);
- alcohol mannitol.
Here's what you need to say, if you are asked: "List the structural features of the kelp."They are really a lot, and they are unique in comparison with other representatives of underwater plants.
use in the economy and the spread
Brown algae - the main source of organic compounds not only herbivorous marine inhabitants, but also for the people living in the coastal zone.Use them in a food widely among different peoples of the world.Of these manufactured medicaments prepared flour and mineral substances, alginic acid.
