2006-09-13 21:03:09 · 7 answers · asked by ajitmat 2 in Science & Mathematics ➔ Biology
It is your homework question. If you had just put the word into Google you would have had the answer by now, without cheating.
2006-09-13 21:08:08 · answer #1 · answered by Anonymous · 0⤊ 0⤋
Cyanobacteria are aquatic and photosynthetic, that is, they live in the water, and can manufacture their own food. Because they are bacteria, they are quite small and usually unicellular, though they often grow in colonies large enough to see. They have the distinction of being the oldest known fossils, more than 3.5 billion years old, in fact! It may surprise you then to know that the cyanobacteria are still around; they are one of the largest and most important groups of bacteria on earth.
Many Proterozoic oil deposits are attributed to the activity of cyanobacteria. They are also important providers of nitrogen fertilizer in the cultivation of rice and beans. The cyanobacteria have also been tremendously important in shaping the course of evolution and ecological change throughout earth's history. The oxygen atmosphere that we depend on was generated by numerous cyanobacteria during the Archaean and Proterozoic Eras. Before that time, the atmosphere had a very different chemistry, unsuitable for life as we know it today.
The other great contribution of the cyanobacteria is the origin of plants. The chloroplast with which plants make food for themselves is actually a cyanobacterium living within the plant's cells. Sometime in the late Proterozoic, or in the early Cambrian, cyanobacteria began to take up residence within certain eukaryote cells, making food for the eukaryote host in return for a home. This event is known as endosymbiosis, and is also the origin of the eukaryotic mitochondrion.
Because they are photosynthetic and aquatic, cyanobacteria are often called "blue-green algae". This name is convenient for talking about organisms in the water that make their own food, but does not reflect any relationship between the cyanobacteria and other organisms called algae. Cyanobacteria are relatives of the bacteria, not eukaryotes, and it is only the chloroplast in eukaryotic algae to which the cyanobacteria are related
2006-09-13 21:07:18 · answer #2 · answered by Anonymous · 1⤊ 0⤋
blue-green algae, photosynthetic bacteria that contain chlorophyll. For many years they were classified in the plant kingdom along with algae, but discoveries made possible by the electron microscope and new biochemical techniques have shown them to be prokaryotes more similar to bacteria than to plants, and they are now placed in the kingdom Monera. Cyanobacteria are familiar to many as a component of pond scum. Despite their name, different species can be red, brown, or yellow; blooms (dense masses on the surface of a body of water) of a red species are said to have given the Red Sea its name. Nitrogen-fixing cyanobacteria need only nitrogen and carbon dioxide to live.
2006-09-13 21:12:24 · answer #3 · answered by chatgal 2 · 0⤊ 0⤋
Used to be called blue-green algae, these are bacteria-like prokaryotes that do photosynthesis.
2006-09-17 12:03:51 · answer #4 · answered by Lorelei 2 · 0⤊ 0⤋
Bacteria made up of cyanide
2006-09-13 21:05:59 · answer #5 · answered by Anonymous · 0⤊ 0⤋
Bacteria that can do photosynthesis. So named for their cyan colour.
2006-09-13 21:11:50 · answer #6 · answered by Who_am_i 1 · 0⤊ 0⤋
blue-green algae
2006-09-13 21:10:33 · answer #7 · answered by MrZ 6 · 0⤊ 1⤋