Did cyanobacteria or seaweed oxygenate the atmosphere?
347938
cyanobacteria...they liked the Carbon and the nitrogen in the primordial atmosphere and they give off oxygen as a product of their metabolism.  But yeah, today seaweed gives off the most oxygen...just think of a forest of trees the size of the atlantic...that's a lot of green!
700720
Seaweed, of course. The sunlight is effective  in that zonal depth.
94116
1. respiration is for animals, and phtosynthesis is for vegetals, bacteria and algae.\n\n2. We (animals) use respiration because our cells need a process called gas exchange ( we take Oxygen from the air and exchange it in our cells for carbon dioxide)\n\n3. This is possible for us because our cells have organs called mitocondria, while vegetal cells have chloroplasts.\n\n4.Photosynthesis is an important biochemical process in which plants, algae, and some bacteria harness the energy of sunlight to produce food. Ultimately, nearly all living things depend on energy produced from photosynthesis for their nourishment, making it vital to life on Earth. It is also responsible for producing the oxygen that makes up a large portion of the Earth's atmosphere. Organisms that produce energy through photosynthesis are called photoautotrophs. Half of all photosynthesis comes not from plants, but from bacteria and algae.\n\nResìration involves the use of developed organs such as lungs.\n\n5. Photosynthesis produces energy from sun light, while\nrespiration produces energy from the Oxygen present in pur atmospheric air.
543438
You should do an experiment, that's what i did.\n \nPhotosynthesis is the production of food compounds from carbon dioxide and water by green plants using energy from sunlight, absorbed by chlorophyll ie. photosynthesis is how plants feed.\n\nlightlightlil\n\n6CO2 + 6H2O                 à C6H12O6 + 6O2\n\n        Raw materials   Products\n\nie.         Green plants make organic substances from inorganic substances.\n\nIn order to keep the equation for photosynthesis simple, glucose is shown as the only food compound produced. However, this does not mean that glucose is not the only food compound produced.\n\nThe process of taking in and giving out gases is known as gaseous exchange. When green plants photosynthesise, they take in CO2 and give out O2. This only happens in daylight when light is available as an energy supply. The exchange of gases in green plants in light is the opposite of that of animals; however this does not mean that green plants do not respire. During daylight, plants photosynthesise and respire at the same time, hence all CO2 produced by the plant during respiration is transformed into O2 and food (and thus energy) for the plant. It is only when the rate of photosynthesis is greater than the rate of respiration that CO2 will be taken in and excess O2 given out.\n\nie.         In darkness O2 is taken in and CO2 is given out - there is no p/s; in dim light the rate of respiration and p/s    is equal - there is no gaseous exchange with the air; in bright light however p/s is faster than respiration          and thus O2 is given out - CO2 is taken in to use for p/s and the CO2 made from the plant’s respiration is   also used to make O2.\n\nie.         The more light (the higher the light intensity), the greater the rate of p/s - unto the LSP [see below].\n\nIf a plant is given plenty of sunlight, carbon dioxide and water, the limit on the rate of p/s is the ability of the plant to absorb these materials and make them react. (eg. total number and capacity of chloroplasts and the physical limitation of carbon dioxide diffusion.) Most of the time plants DO NOT have an unlimited supply and so the rate of p/s is not as high as it might be.\n\nBlackman’s Law states that:\n\n            “The factor in least supply will be the limiting factor.”\n\n\n\nAs the light intensity (LI) increases, the rate of p/s increases, until the plant is photosynthesising as fast as it can - the LSP - Light Saturation Point. When the LSP is reached, plants cannot photosynthesise any faster, even when the light gets brighter. From this point on, according to Blackman’s Law, the factor in least supply will be the limiting factor ie. either CO2, H2O or temperature will be the limiting factor.\n\n\n\nAs the amount of CO2 available increases, the rate of p/s increases, until the plant is photosynthesising as fast as it can - the CSP - CO2 Saturation Point. If both CO2 and light supply are increased together, the rate of p/s will level out. Henceforth it is limited, according to Blackman’s Law, by the factor in least supply, either H2O or temperature. however there is a physical limitation of the carbon dioxide diffusion and the plant’s sunlight absorption.\n\n\n\nAt a lower temperature, the rate of p/s is increasing with increasing LI or CO2 availability, but the LSP or CSP is quickly reached. At a higher temperature, the rate of p/s increased further and reaches the LSP / CSP slower. Thus we can se that temperature affects the rate of p/s - it is higher at higher temperatures.\n\nFrom this information, one can see that if one wants to investigate solely the effect of the quantity of light on Elodea, one must keep both the amount of CO2 and the temperature constant.\n\nLight intensity will decrease as the distance between the light source and the object increases, and vice versa.\n\nThus the relationship between LI and distance can be described as\n\n         1 This value will be very small; multiplying the LI 1000\n\nLI =
696069
Kelp is a great example of a multicellular algae (which is protist), like the "kelp forests" in Alaska.  Check it out.\n\nhttp://www.oceanlight.com/html/kelp.html
995739
cyanobacteria, unchanged for 4 billion years!\n\nhorseshoe crab, the same for 500 million years!
54784
Euglena is a photosynthetic organism. In able to photosynthezise it needs to be exposed to solar radiation, and, in a water environment, that implies living in the top layers of the water, and they use those vesicles as buoyancy.\nParamecium and amoebas are heterotrophic organisms, they do not need solar radiation to survive, so they can lack those vescicles to float on the water.
891771
YOU KNOW THAT OXYGEN IS COLOURLESS AND ODOURLESS SO YOU CAN'T SEE IT AT THE TIME OF ITS PRODUCTION DURING PHOTOSYNTHESIS;THEREFORE ITS EXPERIMENT IS CARRIED OUT UNDER WATER BECAUSE IN WATER YOU CAN SEE OXYGEN BY FORMATION OF BUBBLES.
804350
Plants don't inhale oxygen, they "inhale" carbon dioxide and release it to make oxygen.
189813
Yes gasses in the air (oxygen, nitrogen, CO2, etc.) dissolve in the water (hence the fish and algae breath). Also many pollutants also dissolve in water (much easier than the gasses). If they are present in the air they will dissolve in the water, either by transfer (just the pollutants, not the gasses) or with the gasses.
97554
Dude plants and algea, planton converting carbon dioxide to oxogen in photosythesis. Plus those weird bacteria in the ocean that can do it without light in darkness.
1123212
Not a very well phrased question.  But dissolved CO2 and O2 in water are primarily from the lifeforms inhabiting the water, such as plants, bacteria, and others.  Inorganic chemical reactions (such as volcanic activities) would also contribute to the changes in O2/CO2 balance.
1119264
Yes, algae are the primary producers but the broader group is Phytoplanktons.
398613
Actually, animals preceded plants by a long way-The oxygen first produced was made by cyanobacteria and algae, not plants.  Plants did precede animals onto land, however.  Short answer, we evolved side-by-side for a very short period of time, prior to the formation of choroplasts some billion years ago or so, and after that have evolved separately.
874799
Photosynthesis is the process that all green plants use to convert water and nutrients with the aid of chlorophyll\nand energy from sunlight into food(glucose).\nrespiration is only part of the process that allows all living things(including plants) to produce energy via andosine triphosphate breakdown to grow, move and reproduce. respiration is the process of transporting air(oxygen)into the body to allow breakdown of food into energy and waste products\ngirl, you need more confidence in yourself.\ni don't have a major in biology, infact i only have what you call high school education.\nsome people may want to fool you.\nGod bless,\ngabe\nps, algae is a plant, it may be single celled , but still a plant.
92571
cyanobacteria, aka blue green algae, contain chlorophyll and carry on photosynthesis like green plants.\nThe second reference (tolweb.org)lists lots of them if you need specific examples
875787
Well, this happened once before.  Originally the earth had a very low concentration of atmospheric oxygen and oxygen was toxic to most organisms (they were all single celled back then).  But as organisms started to develop photosynthesis, oxygen was released into the atmosphere in huge amounts causing a massive extinction.  Now most organisms need or tolerate oxygen.  I'm not sure what would happen if the %O2 was increased now......I bet that plants wouldn't like it though.