Există alge monocelulare (clorela, claminominada ș. a.) și alge pluricelulare (oscilatoria, ulotriscul, laminaria ș. a.). Dimensiunile lor variază de la miimi de milimetru la zeci de metri. Componența chimică a corpului algelor este în funcție de bazinul de apă (mare, râu, lac, iaz) în care cresc. De regulă, algele populează grosul apei, se dezvoltă pe fundul bazinelor sau pe. Algele (lat. Algae - „iarbă de mare”) constituie un grup diversificat din Regnul Chromista, Regnul Plante dar și unele organisme din Regnul Monera Cuprins 1 Caracteristicile generale ale algelor. Algae are simple plants that can range from the microscopic (microalgae), to large seaweeds (macroalgae), such as giant kelp more than one hundred feet in length. Microalgae include both cyanobacteria, (similar to bacteria, and formerly called “blue-green algae”) as well as green, brown and red algae.

For a discussion of the related protists, see the articles protozoan and protist. For a more complete discussion of photosynthesis, see the articles photosynthesis and plant.

Algae Article Media Additional Info. Article Contents. Print print Print. Table Of Contents. Facebook Twitter. Give Feedback External Websites.

Let us know if you have suggestions to improve this article requires login. External Websites. Commonly, in sexual reproduction of unicellular and colonial algae, two specialized, sexually compatible, haploid gametes make physical contact and fuse to form a zygote.

To ensure a successful mating, the development and release of gametes is highly synchronized and regulated; pheromones may play a key role in these processes.

The Algal Collection of the US National Herbarium located in the National Museum of Natural History consists of approximately , dried specimens, which, although not exhaustive no exhaustive collection exists , gives an idea of the order of magnitude of the number of algal species that number remains unknown.

Another checklist reports only about 5, species. Regarding the difference of about 15, species, the text concludes: "It will require many detailed field surveys before it is possible to provide a reliable estimate of the total number of species Most estimates also omit microscopic algae, such as phytoplankton.

The most recent estimate suggests 72, algal species worldwide. The distribution of algal species has been fairly well studied since the founding of phytogeography in the midth century.

This dispersal can be accomplished by air, water, or other organisms. Due to this, spores can be found in a variety of environments: fresh and marine waters, air, soil, and in or on other organisms.

The spores of freshwater algae are dispersed mainly by running water and wind, as well as by living carriers. Ocean water presents many vastly different habitats based on temperature and nutrient availability, resulting in phytogeographic zones, regions, and provinces.

To some degree, the distribution of algae is subject to floristic discontinuities caused by geographical features, such as Antarctica , long distances of ocean or general land masses.

It is, therefore, possible to identify species occurring by locality, such as "Pacific algae" or "North Sea algae". When they occur out of their localities, hypothesizing a transport mechanism is usually possible, such as the hulls of ships.

For example, Ulva reticulata and U. Mapping is possible for select species only: "there are many valid examples of confined distribution patterns.

Algae are prominent in bodies of water, common in terrestrial environments, and are found in unusual environments, such as on snow and ice. The various sorts of algae play significant roles in aquatic ecology.

Microscopic forms that live suspended in the water column phytoplankton provide the food base for most marine food chains.

In very high densities algal blooms , these algae may discolor the water and outcompete, poison, or asphyxiate other life forms.

Algae can be used as indicator organisms to monitor pollution in various aquatic systems. Due to this, the species composition of algal populations may shift in the presence of chemical pollutants.

On the basis of their habitat, algae can be categorized as: aquatic planktonic , benthic , marine , freshwater , lentic , lotic , [69] terrestrial , aerial subaerial , [70] lithophytic , halophytic or euryhaline , psammon , thermophilic , cryophilic , epibiont epiphytic , epizoic , endosymbiont endophytic , endozoic , parasitic , calcifilic or lichenic phycobiont.

Agar , a gelatinous substance derived from red algae, has a number of commercial uses. Alginic acid, or alginate, is extracted from brown algae.

Its uses range from gelling agents in food, to medical dressings. Alginic acid also has been used in the field of biotechnology as a biocompatible medium for cell encapsulation and cell immobilization.

Molecular cuisine is also a user of the substance for its gelling properties, by which it becomes a delivery vehicle for flavours.

Between , and , wet tons of Macrocystis are harvested annually in New Mexico for alginate extraction and abalone feed.

To be competitive and independent from fluctuating support from local policy on the long run, biofuels should equal or beat the cost level of fossil fuels.

Here, algae-based fuels hold great promise, [75] [76] directly related to the potential to produce more biomass per unit area in a year than any other form of biomass.

The break-even point for algae-based biofuels is estimated to occur by For centuries, seaweed has been used as a fertilizer; George Owen of Henllys writing in the 16th century referring to drift weed in South Wales : [78].

This kind of ore they often gather and lay on great heapes, where it heteth and rotteth, and will have a strong and loathsome smell; when being so rotten they cast on the land, as they do their muck, and thereof springeth good corn, especially barley After spring-tydes or great rigs of the sea, they fetch it in sacks on horse backes, and carie the same three, four, or five miles, and cast it on the lande, which doth very much better the ground for corn and grass.

Today, algae are used by humans in many ways; for example, as fertilizers , soil conditioners , and livestock feed. Algaculture on a large scale is an important type of aquaculture in some places.

Maerl is commonly used as a soil conditioner. Naturally growing seaweeds are an important source of food, especially in Asia. They provide many vitamins including: A, B 1 , B 2 , B 6 , niacin , and C , and are rich in iodine , potassium , iron, magnesium , and calcium.

Algae are national foods of many nations: China consumes more than 70 species, including fat choy , a cyanobacterium considered a vegetable; Japan, over 20 species such as nori and aonori ; [82] Ireland, dulse ; Chile , cochayuyo.

Sea lettuce and badderlocks are salad ingredients in Scotland , Ireland, Greenland , and Iceland. Algae is being considered a potential solution for world hunger problem.

The oils from some algae have high levels of unsaturated fatty acids. Fish oil contains the omega-3 fatty acids, but the original source is algae microalgae in particular , which are eaten by marine life such as copepods and are passed up the food chain.

Scientists developed the ATS, which consists of shallow, foot raceways of nylon netting where algae colonies can form, and studied its efficacy for three years.

They found that algae can readily be used to reduce the nutrient runoff from agricultural fields and increase the quality of water flowing into rivers, streams, and oceans.

Researchers collected and dried the nutrient-rich algae from the ATS and studied its potential as an organic fertilizer. They found that cucumber and corn seedlings grew just as well using ATS organic fertilizer as they did with commercial fertilizers.

Various polymers can be created from algae, which can be especially useful in the creation of bioplastics. These include hybrid plastics, cellulose based plastics, poly-lactic acid, and bio-polyethylene.

The alga Stichococcus bacillaris has been seen to colonize silicone resins used at archaeological sites; biodegrading the synthetic substance.

The natural pigments carotenoids and chlorophylls produced by algae can be used as alternatives to chemical dyes and coloring agents.

Carrageenan, from the red alga Chondrus crispus , is used as a stabilizer in milk products. From Wikipedia, the free encyclopedia. For places called Alga, see Alga disambiguation.

For other uses, see Algae disambiguation. Diverse group of photosynthetic eukaryotic organisms. An informal term for a diverse group of photosynthetic eukaryotes.

Temporal range: Mesoproterozoic—present [1]. Further information: wikispecies:Algae. Main article: Lichen.

Main articles: Coral , Coral reef , and Symbiodinium. Main article: Sea sponge. Further information: Conceptacle. Further information: Seaweed fertiliser.

See also: Edible seaweed and Algae powder. Main articles: Carrageenan and Chondrus crispus. Archived from the original on 7 March Cambridge University Press.

Introduction to Botany. San Francisco: Pearson Education, Inc. The Concise Dictionary of Botany. Oxford University Press.

American Journal of Botany. Archived from the original on 27 February Archived from the original on 2 July Retrieved 25 August Farblose Algen.

Ein beitrag zur Evolutionsforschung. Gustav Fischer Verlag, Stuttgart. International Journal of Systematic and Evolutionary Microbiology. New Phytologist.

Bibcode : PNAS.. A Latin Dictionary. Oxford: Clarendon Press. Retrieved 31 December Macmillan Company. Vashishta Revised by A. Sinha and V.

Singh Botany for degree students algae. New Delhi: S. Chand and Company. Plant Physiology. Archived PDF from the original on 7 February Biology 8 ed.

November Trends in Genetics. December PLOS Genetics. Butler, Geraldine ed. There are more varieties of microalgae, but these are the main ones.

Algae can be grown using water resources such as brackish-, sea-, and wastewater unsuitable for cultivating agricultural crops.

When using wastewater, such as municipal, animal and even some industrial runoff, they can help in its treatment and purification, while benefiting from using the nutrients present.

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We also use third-party cookies that help us analyze and understand how you use this Free Video Slots. Agentur K. Über Services Details Stellen Kontakt. These cookies do not store any personal information. Morning Edition. Introduction to Botany. Main articles: Carrageenan and Chondrus crispus. Journal of Phycology. The Algal Collection of the US National Herbarium located in the National Museum of Natural History consists of approximatelydried specimens, which, although not exhaustive no exhaustive collection existsSpieleanbieter an idea of the order Kostenlos Spielen Casino magnitude of the number of algal species that number remains unknown. With nutrient pollution, there is an excess of nitrogen and phosphorus, which can push algae toward unrestrained growth. Enter your email and join our Alge Alge Alge list for updates and news on the industry. Ein beitrag zur Evolutionsforschung. Most are aquatic and autotrophic and lack many of the distinct cell and tissue types, such as stomataxylem and phloemwhich are found in land plants. Algae Article Media Additional Info. Further information: Conceptacle. Marine Algae of California. London: Cambridge University Press. In these symbioses, the algae supply photosynthates organic substances to the host organism providing protection to the algal cells. Visibility Others Premier League Lol see my Clipboard.

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Der einzig wahre König. Kim Huybrechts 46". Lembi, C. Applied and Environmental Microbiology. More information: Nicky Atkinson et al.