Related topics: climate change , biofuel , photosynthesis
Algae
hideAlgae (pronounced /ˈældʒiː/; singular alga /ˈælɡə/, Latin for "seaweed") are a large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms. The largest and most complex marine forms are called seaweeds. They are photosynthetic, like plants, and "simple" because they lack the many distinct organs found in land plants. For that reason they are currently excluded from being considered plants.
Though the prokaryotic Cyanobacteria (commonly referred to as Blue-green Algae) were traditionally included as "Algae" in older textbooks, many modern sources regard this as outdated and restrict the term Algae to eukaryotic organisms. All true algae therefore have a nucleus enclosed within a membrane and chloroplasts bound in one or more membranes. Algae constitute a paraphyletic and polyphyletic group, as they do not include all the descendants of the last universal ancestor nor do they all descend from a common algal ancestor, although their chloroplasts seem to have a single origin.
Algae lack the various structures that characterize land plants, such as phyllids and rhizoids in nonvascular plants, or leaves, roots, and other organs that are found in tracheophytes. Many are photoautotrophic, although some groups contain members that are mixotrophic, deriving energy both from photosynthesis and uptake of organic carbon either by osmotrophy, myzotrophy, or phagotrophy. Some unicellular species rely entirely on external energy sources and have limited or no photosynthetic apparatus.
Nearly all algae have photosynthetic machinery ultimately derived from the Cyanobacteria, and so produce oxygen as a by-product of photosynthesis, unlike other photosynthetic bacteria such as purple and green sulfur bacteria. Fossilized filamentous algae from the Vindhya basin have been dating back to 1.6 to 1.7 billion years ago.
The first alga to have its genome sequenced was Cyanidioschyzon merolae.
For more information about Algae, read the full article at
Wikipedia.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.
News tagged with algae
Watching Proteins Direct Crystal Growth One Step at a Time (w/ Video)
Dec 16, 2009 |
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(PhysOrg.com) -- Scientists at Berkeley Lab's Molecular Foundry imaged the growth of protein-studded mineral surfaces with unprecedented resolution and provided a glimpse into how living systems engineer key ...
Sick of swine flu? Toxic algae could be the next big threat
Dec 15, 2009 |
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With a new theory surfacing that toxic algae rather than asteroids killed the dinosaurs, scientists are still trying to unravel the mystery of what caused a massive algae bloom off the Northwest Coast that left thousands ...
Researchers Identify Key Molecules in Photosynthesis
Dec 02, 2009 |
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(PhysOrg.com) -- Chemistry professor Harry Frank led an international group of researchers that identified the molecules in algae which direct the organisms to convert sunlight into oxygen. The findings may ...
Golden Oldie: Key Role for Ancient Protein in Algae Photosynthesis
Nov 27, 2009 |
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The discovery that an ancient light harvesting protein plays a pivotal role in the photosynthesis of green algae should help the effort to develop algae as a biofuels feedstock. Researchers with the Lawrence ...
Last time carbon dioxide levels were this high: 15 million years ago, scientists report
Space & Earth / Earth Sciences
Oct 08, 2009 |
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You would have to go back at least 15 million years to find carbon dioxide levels on Earth as high as they are today, a UCLA scientist and colleagues report Oct. 8 in the online edition of the journal Science.
Paper battery may power electronics in clothing and packaging material
Nanotechnology / Nanomaterials
Sep 23, 2009 |
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Imagine a gift wrapped in paper you really do treasure and want to carefully fold and save. That's because the wrapping paper lights up with words like "Happy Birthday" or "Happy Holidays," thanks to a built ...
Killer algae a key player in mass extinctions
Space & Earth / Earth Sciences
Oct 19, 2009 |
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Algae, not asteroids, were the key to the end of the dinosaurs, say two Clemson University researchers. Geologist James W. Castle and ecotoxicologist John H. Rodgers have published findings that toxin producing ...
Forests of Artificial Trees Could Slow Global Warming
Aug 28, 2009 |
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(PhysOrg.com) -- A new study on how technology could help to regulate climate change has studied hundreds of ideas, and selected three considered practical and able to be implemented quickly. The report's ...
Troublesome green algae serve as coating substrate in record-setting battery
Nanotechnology / Nanomaterials
Sep 10, 2009 |
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(PhysOrg.com) -- Unwanted blooms of Cladophora algae throughout the Baltic and in other parts of the world are not entirely without a positive side. A group of researchers at the Angstrom Laboratory at Uppsala University have d ...
'Safety valve' protects photosynthesis from too much light
Nov 25, 2009 |
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Photosynthetic organisms need to cope with a wide range of light intensities, which can change over timescales of seconds to minutes. Too much light can damage the photosynthetic machinery and cause cell death. Scientists ...
Hydrogen-making algae's 'Achilles' heel' discovered
Sep 29, 2009 |
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(PhysOrg.com) -- Scientists have discovered how oxygen stops green algae from producing hydrogen. The findings could help those working towards 'solar H2-farms' in which microorganisms produce hydrogen fuel ...
Algae may be secret weapon in climate change war
Oct 22, 2009 |
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Driven by fluctuations in oil prices, and seduced by the prospect of easing climate change, experts are ramping up efforts to squeeze fuel out of a promising new organism: pond scum.
A new day dawned fast: Recovery from marine mass extinction happened much faster than thought
Space & Earth / Earth Sciences
Oct 02, 2009 |
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(PhysOrg.com) -- In 1979, Luis Alvarez and his collaborators stunned the world with their discovery that an asteroid impact 65 million years ago probably killed off the dinosaurs and much of the the world's ...
Scientists find 'Lucky Luke' of the seas
Sep 03, 2009 |
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Could you filter 100,000 cubic metres of syrup every day to find food in a concentration of two grains of rice per cubic metre?
15,000 reasons to worry about invasive species
Nov 09, 2009 |
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A day at the beach in Wisconsin's North Woods didn't used to go like this. Candy Dailey spent a Fourth of July holiday splashing with grandkids on the sandy shore of Lake Metonga when she felt a nasty sting on her foot.
