蓝藻是一种原核的低等藻类植物,有30亿年的历史,共有2,000多种,其中具固氮能力的有100多种。无根、茎、叶、花之分,由于细胞内含有大量藻蓝素,故呈蓝绿色。在显微镜下,看到藻丝上有几个较大而透明的细胞,叫做“异形胞”。凡具固氮能力的蓝藻都有“异形胞”;凡没有“异形胞”的蓝藻均无固氮能力。因此,有无“异形胞”是区别能否固氮的重要标志。固氮蓝藻的细胞内含有色素,吸收空气中的二氧化碳,通过太阳光进行光合作用,不断生长。细胞直接分裂,l分为2,2分为4……。多数能形成段殖体(藻殖段),脱离母体发育成新藻丝;有的能产生孢子,当外界条件适合时,萌发成新藻体。它之所以具 Cyanobacteria is a prokaryotic low-grade algae with a history of 3 billion years and a total of more than 2,000 species, of which more than 100 are nitrogen-fixing. Roots, stems, leaves, flowers of the points, because the cells contain large amounts of phycocyanin, it was blue-green. Under the microscope, there are several larger and transparent cells on the filament of the sliver called “alien cells.” Where have the ability to fix nitrogen have algae “alien cells”; where there is no “alien cells” are no nitrogen-fixing capacity of cyanobacteria. Therefore, whether or not “alien cells” is an important symbol to distinguish between nitrogen fixation. Nitrogen fixation Cyanobacterial cells contain pigments, absorbing carbon dioxide in the air, photosynthesis through the sun, growing. Cell division directly, l divided into 2,2 divided into 4 ....... Most can form a segment of the body (algae segment), separated from the mother into a new algae silk; some can produce spores, when the external conditions fit, germination into a new algae. The reason why it has