Algae is commercially cultivated as a nutritional supplement.
The per unit area yield of oil from algae is at least 15 times greater than the next best crop, palm oil.
Algae are usually found in damp places or bodies of water and thus are common in aquatic environments, but they are also found in terrestrial locales.
Algae frequently form part of a symbiosis with other organisms.
Most unicellular and colonial algae are aquatic, and float near the surface of the water.
Some scientists include as algae the prokaryotic (simple cell structure lacking a nucleus or organelles) cyanobacteria, which are aquatic, photosynthetic, and commonly known as "blue-green algae."
The name alga (plural algae) comes from the Latin word for seaweed.
Algae are the base of the aquatic food chain.
Algae can be grown in tanks, raceway-type ponds, and lakes.
Some filamentous blue-green algae have specialized cells, termed heterocysts, in which nitrogen fixation occurs.
Multicellular algae may consist of a row of cells, appearing as a filament, or as a thin plate of cells, or even some larger ones may have bodies with a rudimentary division of labor.
Most of the seaweeds of the warm oceans are red algae.
Algae can be harvested using microscreens, by centrifugation, or by flocculation.
The various types of algae play significant roles in ecology.
Algae (singular alga) are a large and diverse group of photosynthetic, eukaryotic, plant-like organisms that use chlorophyll in capturing light energy, but lack characteristic plant structures such as leaves, roots, flowers, vascular tissue, and seeds.
Algae sometimes are defined as "photosynthetic protists"; however, some taxonomic schemes do not limit them to this kingdom.
Terrestrial algae are usually rather inconspicuous and far more common in moist, tropical regions than dry ones, because algae lack vascular tissues and other adaptations to live on land.
The seaweeds grow mostly in shallow marine waters, but some, such as the red algae, can grow quite deep in the ocean.
All algae have photosynthetic machinery that is considered to derive from the cyanobacteria, and so produce oxygen as a by-product of photosynthesis, unlike the non-cyanobacterial photosynthetic bacteria.
Red and green algae have an "alternation of generations" life cycle.
Sometimes the prokaryotic cyanobacteria, given their aquatic and photosynthetic characteristic, have been included among the algae, and have been referred to as the cyanophytes or blue-green algae.
Green aquatic, the most diverse algae with over seven thousand identified species, are generally aquatic, and the majority are freshwater organisms.
Most of the simpler algae are unicellular flagellates or amoeboids, but colonial and non-motile forms have developed independently among several of the groups.
Among algal species cultivated for their nutritional value include chlorella (a green algae) and dunaliella (Dunaliella salina), which is high in beta-carotene and is used in vitamin C supplements.
Algae is used in the Chinese "vegetable" known as fat choy (which is actually a cyanobacterium).
The carbon dioxide is pumped into a pond, or some kind of tank, on which the algae feed.
The most complex forms are found among the green algae, in a lineage that is considered to have eventually led to the higher land plants.
Algae can endure dryness and other conditions in symbiosis with a fungus as lichen.
The natural pigments produced by algae can be used as an alternative to chemical dyes and coloring agents.
The exact nature of the chloroplasts is different among the different lines of algae, possibly reflecting different endosymbiotic events.
The brown algae include the major seaweeds found on the shores in the temperate zones and the large, offshore beds of kelps.
Many common products, such as hand lotion, lipstick, paint, and ice cream, contain derivatives from algae.
The photosynthetic work done by algae is believed to produce more than three-quarters of the oxygen in the earth's atmosphere; far more than that produced by terrestrial plants.
Algae also can be grown in polyethylene sleeves, and in a photobioreactor.
The designation algae includes diverse phyla, including diatoms (golden algae), green algae, euglenoids (flagellates), brown algae, and red algae, and range from single-celled organisms to giant seaweeds.
Some algae reproduce both sexually and asexually, such as the green algae (for example, Chlamydomonas, a unicellular green algae).
Algae can be used to produce biodiesel fuel, and by estimates can potentially produce superior amounts of oil compared to land-based crops.
The study of algae is called phycology or algology.
Recent treatises on algae often exclude them, and consider as algae only eukaryotic organisms.
The point where these non-algal plants begin and algae stop is usually taken to be the presence of reproductive organs with protective cell layers, a characteristic not found in the other algal groups.
The term algae is mainly used for convenience, rather than taxonomic purposes, as there appears little relationship between the various phyla.
Algae range from single-celled organisms to multi-cellular organisms, some with fairly complex differentiated form and, if marine, called seaweeds.
Algae are used in many wastewater treatment facilities, reducing the need for harmful chemicals, and are used in some power plants to reduce carbon dioxide emissions.