Hypothetical types of biochemistry in the late 1960s, these machines are often classed as computers (or computer-guided robots) and filed under "silicon-based life", even though the silicon backing matrix of these processors is not nearly as fundamental to their operation as carbon is for "wet life". Arsenic, which is chemically similar to phosphorus, while poisonous for most life forms on Earth, is incorporated into the biochemistry of some organisms. Some marine algae incorporate arsenic into complex organic molecules such as arsenosugars and arsenobetaines. Fungi and bacteria can produce volatile methylated arsenic compounds. Arsenate reduction and arsenite oxidation have been observed in microbes ("Chrysiogenes arsenatis").
Tamil Nadu cultivated plants and 230 red-listed species. The Gymnosperm diversity of the country is 64 species of which Tamil Nadu has four indigenous species and about 60 introduced species. The Pteridophytes diversity of India includes 1022 species of which Tamil Nadu has about 184 species. Vast numbers of bryophytes, lichen, fungi, algae and bacteria are among the wild plant diversity of Tamil Nadu. Common plant species include the state tree: palmyra palm, eucalyptus, rubber, cinchona, clumping bamboos ("Bambusa arundinacea"), common teak, "Anogeissus latifolia", Indian laurel, grewia, and blooming trees like Indian labumusum, ardisia, and solanaceae. Rare and unique plant life includes