underwater world has always attracted a person with its brightness, unprecedented beauty, diversity and unexplored mysteries.Amazing animals, stunning plants of different sizes - all of these unusual organisms do not leave anyone indifferent.In addition to the visible eye of major species of flora, there are also tiny, foreseeable only under a microscope, but that does not lose its importance and significance in the total biomass of the ocean.This single-celled algae.If you take the total production of organic matter generated by underwater plants that produce most of it is they, these tiny and amazing creatures.
Algae: general characteristics
In general, algae - a subkingdom Lower plants.They belong to the group on the grounds that their body is not differentiated organs, and is represented by a continuous (sometimes dissected) or thallus thallus.Instead of the root system, they have provisions for attachment to the substrate in the form rhizoids.
This group of organisms is very numerous, varied in form and structure, way of life and habitats.There are the following sections of this family:
- red;
- brown;
- green;
- gold;
- diatoms;
- cryptophytae;
- yellow-green;
- Euglenophyta;
- dinoflagellate.
Each of these departments may include in its membership representatives of unicellular algae and with multicellular thallus.Also, there are the following forms of organisms:
- colonial;
- filamentous;
- free-;
- attached and others.
attributes for classification can be found set.One of the most important defining in practical terms - a way to absorb energy.Representatives of the green unicellular algae are all autotrophs, most multicellular organisms of the same class and carry out photosynthesis.However, there are heterotrophic, mixotrophic and even parasitic forms.
studied in more detail the structure, vitality and reproduction of Representatives is unicellular organisms belonging to different classes of algae.We estimate their role in nature and human life.
avilable unicellular algae
What are the specific features that allow these tiny organisms exist?Firstly, even though they have only a single cell, but it performs all the vital functions of the whole organism:
- growth;
- development;
- food;
- breathing;
- reproduction;
- movement;
- selection.
also these single-celled organisms inherent feature of irritability.
In its internal structure features single-celled algae that can surprise the researchers concerned, have not.The same structure and organelles and in cells that higher organisms.Cell membrane has the ability to absorb the surrounding moisture, thus, the body may be submerged.This allows the algae to settle more widely, not only in the seas, oceans and other water bodies, but also on land.
core of genetic material are all members, except for blue-green algae, which are prokaryotic organisms.Also, the cell organelles include standard required:
- mitochondria;
- cytoplasm;
- endoplasmic reticulum;
- Golgi apparatus;
- lysosomes;
- ribosome;
- cell center.
feature is the presence of plastids that contain one or the other pigment (chlorophyll, xanthophylls, phycoerythrin, etc.).Also interesting is the fact that the single-celled algae can move freely in the water column by means of one or more flagella.However, not all kinds.There are also attached to the substrate shape.
Distribution and habitat
Due to the small size and some features of the structure, single-celled algae were able to spread around the globe.They inhabit:
- fresh water;
- seas and oceans;
- swamp;
- the surface of rocks, trees, stones;
- polar plains covered with snow and ice;
- aquariums.
Where they just can not be found!For nostokovye unicellular algae, examples of blue-green cyanobacteria, or - the inhabitants of the permafrost in Antarctica.Due to the composition of different pigments, these organisms are wonderfully decorated with a snow-white landscape.It stains the snow in pink, purple, green, purple and blue colors, which, of course, looks very nice.
Green unicellular algae, examples of which can be reduced as follows: chlorella, trentepohlia, chlorococcum, pleurococcus - live on the surface of trees, covering them with bark green patina.They are forced to buy the same color of the surface of the stones, the top layer of water, land, cliffs and other places.They belong to a group of ground or aerial algae.
Generally, representatives of unicellular algae are all around us, just notice them is possible only with a microscope.In the water, the air, on surfaces of products, land, plants and animals live in the red, green and golden algae and cyanobacteria.
Reproduction and lifestyles
lifestyle of a particular alga should say in each case.Some people prefer to float freely in the water, forming phytobenthos.Other animals are placed inside the body, engaging with them in a symbiotic relationship.Others simply attached to the substrate and form colonies and filament.
But the multiplication of unicellular algae - a process similar in all members.This is a normal vegetative division two, mitosis.The sexual process is extremely rare, and only upon the occurrence of adverse living conditions.
Asexual reproduction is reduced to the following steps.
- Preparatory.The cell grows and develops, collects nutrients.
- reducing traffic organelles (flagella).
- Then begins the process of DNA replication and the simultaneous formation of transverse waist.
- Centromeres stretch the genetic material of different poles.
- Padding closes and the cell divides in two.
- Cytokinesis occurs simultaneously with all of these processes.
The result - the new daughter cells identical to the parent.They finish building the missing parts of the body and begin an independent life, growth and development.Thus, the life cycle of a single-celled individuals begins and ends with the division by him.
avilable green unicellular algae
main feature - a rich green color, which is a cell.It is explained by the fact that in the plastid predominant pigment chlorophyll.That is why these organisms are capable of photosynthesis, producing organic matter for himself alone.This makes them largely to the higher ground of flora.
also structural features of the green unicellular algae are as the following general laws.
- reserve nutrients - starch.
- Such organelles like the chloroplast is surrounded by a double membrane that is found in higher plants.
- move using flagella covered with hairs and scales.There may be from one up to 6-8.
obvious that the structure of the green unicellular algae makes them special and closer to the highly organized representatives of terrestrial species.
Who belongs to this department?The most famous representatives:
- chlamydomonas;
- Volvox;
- Chlorella;
- pleurococcus;
- euglena green;
- akrosifoniya and others.
Let us consider a few of these organisms.
Chlamydomonas
This refers to the representative of the department such as green unicellular algae.Chlamydomonas - is mostly freshwater organisms, it has some features of the structure.It is characterized by positive phototaxis (movement toward the source of light), due to the presence at the front end of the photosensitive cells of the eyelet.
biological role of Chlamydomonas is that it is a producer of oxygen during photosynthesis, a valuable source of feed for livestock.Also, this is the cause algae "bloom" of water bodies.The cells are easy to cultivated in artificial conditions, so Chlamydomonas Genetics chosen as an object of research and laboratory experiments.
Chlorella
unicellular algae Chlorella also applies to the Department of green.Its main difference from all the others that she lives only in fresh water, and its cell devoid of flagella.The ability to photosynthesize chlorella can be used as a source of oxygen in the space (on ships, missiles).
Inside the cell contains a unique set of nutrients and vitamins, owing to which the algae is highly valued as a food supply for livestock.Even for a person eating it to eat it would be very beneficial, because 50% of the protein in its composition superior to the energy value of many crops.However, as food for people, it is still not taken root.
But chlorella has been used successfully for biological purification of water.Watch this organism can be in glass containers of stagnant water.On the walls formed a slippery patina green.This is chlorella.
euglena
green unicellular algae is euglena green, which belongs to the Department of Euglena.The unusual, long with a pointed end shape of the body makes it different from others.It also has a light-sensitive eye and an active movement of the flagellum.An interesting fact is that euglena - mixotrophy.It can be powered heterogeneous, but in most cases it carries out the process of photosynthesis.
For a long time there were disputes about belonging of the body to any realm.According to further features an animal, on the other - a plant.She inhabits in waters contaminated with organic residues.
pleurococcus
This round green organisms living on the rocks, earth, rocks, trees.Form a blue-green patina on surfaces.Belongs to the family Hetoforovye algae green card.
That pleurococcus possible to navigate in the woods, as he settled only on the north side of trees.
Diatoms are unicellular algae
is a diatom, and all the attendant species.Together they form the diatoms, which are different interesting feature.On top of the cell covered with a beautiful patterned shell, on which a natural pattern from the salts of silicon and its oxide.Sometimes these patterns are so incredible that it seems as if this is some elaborate architectural structure and design of the artist.
Over time, the representatives of the dead diatoms constitute valuable deposits of rocks, which are used by man.As part of the cell is dominated by xanthophylls, so painting of golden algae.Is a valuable food for marine animals, because they form a significant part of the plankton.
Red algae
These are species whose coloration varies from light-red to orange and maroon.As part of the cell is dominated by other pigments that inhibit chlorophyll.We are interested in red algae, unicellular forms.
This group includes bangievyh class of algae, which includes approximately 100 species.Of these, a significant part consists of single-celled.The main difference is the predominance of carotenes and xanthophylls, phycobilins of chlorophyll.This explains the painting department spokesman.There are some of the most common among single-celled organisms red algae:
- Porphyridium.
- hrootetse.
- geotrihum.
- asterotsitis.
main habitat - the ocean and marine waters in temperate latitudes.In the tropics, it is much rarer.
Porphyridium
Watch, inhabited by single-celled algae of the species, everyone can.They form the blood-red of the film on the ground, walls and other damp surfaces.Solitary creatures rarely, mostly collected in the colonies surrounded by slime.
man used to study processes such as photosynthesis in unicellular and education polysaccharide molecules inside the body.
Hrootetse
This is a single-celled algae, and also refers to the Department of red, class bangievyh.Its main distinguishing feature - is the formation of mucous "legs" to attach to the substrate.Interestingly, this "foot" may exceed the size of the body is almost 50 times.Mucus is produced by the cell in the process of life.
infests the body on soils, as forming a conspicuous red mud, slippery to the touch.
