Cylindrospermopsis raciborskii mild skin reactions upon exposure. The last two toxins, anatoxin-a and saxitoxin, are thought to be shellfish neurotoxins. Research has shown that "C. raciborskii" can naturally produce butylated hydroxytoluene, an antioxidant, food additive, and industrial chemical. Domain – Bacteria The Tree of Life contains three Domains: Bacteria, Archaea, and Eukarya. Kingdom – Bacteria Bacteria consists of prokaryotic microorganisms. They were among the first life forms to appear on Earth and appear in a wide variety of habitats. Phylum – Cyanobacteria This phylum is characterized by their ability to obtain energy through photosynthesis. They are often called the blue-green algae stemming
Algae their relationship with algae conjectured early. In other cases, some groups were originally characterized as parasitic algae (e.g., "Chlorochytrium"), but later were seen as endophytic algae. Some filamentous bacteria (e.g., "Beggiatoa") were originally seen as algae. Furthermore, groups like the apicomplexans are also parasites derived from ancestors that possessed plastids, but are not included in any group traditionally seen as algae. The first land plants probably evolved from shallow freshwater charophyte algae much like "Chara" almost 500 million years ago. These probably had an isomorphic alternation of generations and were probably filamentous. Fossils of isolated land plant spores suggest land