Information: - The heterokonts or stramenopiles (formally, Heterokonta or Stramenopiles) are a major line of eukaryotes currently containing more than 25,000 known species. Most are algae, ranging from the giant multicellular kelp to the unicellular diatoms, which are a primary component of plankton. Other notable members of the Stramenopiles include the (generally) parasitic oomycetes, including "Phytophthora" of Irish potato famine infamy and "Pythium" which causes seed rot and damping off. - Pythium is a genus of parasitic oomycotes. They were formerly classified as fungi. Most species are plant parasites, but "Pythium insidiosum" is an important pathogen of animals, causing Pythiosis. The feet of the fungus gnat are frequently a vector for their transmission. - Seaweed refers to several species of macroscopic, multicellular, marine algae. - Diatoms are a major group of algae, and are among the most common types of phytoplankton. Diatoms are unicellular, although they can form colonies in the shape of filaments or ribbons (e.g. "Fragilaria"), fans (e.g. "Meridion"), zigzags (e.g. "Tabellaria"), or stars (e.g. "Asterionella"). The first diatom formally described in scientific literature, the colonial "Bacillaria paradoxa", was found in 1783 by Danish naturalist Otto Friedrich Muller. Diatoms are producers within the food chain. A unique feature of diatom cells is that they are enclosed within a cell wall made of silica (hydrated silicon dioxide) called a frustule. These frustules show a wide diversity in form, but are usually almost bilaterally symmetrical, hence the group name. The symmetry is not perfect since one of the valves is slightly larger than the other, allowing one valve to fit inside the edge of the other. Fossil evidence suggests that they originated during, or before, the early Jurassic period. Only male gametes of centric diatoms are capable of movement by means of flagella. Diatom communities are a popular tool for monitoring environmental conditions, past and present, and are commonly used in studies of water quality. - Dictyochales ( or Silicoflagellates ) are a small group of unicellular heterokont algae , found in marine environments . - Charophyta is a division of freshwater green algae. The terrestrial plants, the Embryophyta emerged within Charophyta, with the class Zygnematophyceae as a sister group. In some charophyte groups, such as Zygnematophyceae or conjugating green algae, flagellae are absent and sexual reproduction does not involve free-swimming flagellate sperm. Flagellate sperm, however, are found in stoneworts (Charales) and Coleochaetales, orders of parenchymatous charophytes that are the closest relatives of the land plants, where flagellate sperm are also present in all except the conifers and flowering plants. Fossil stoneworts of Devonian age that are similar to those of the present day have been described from the Rhynie chert of Scotland. - Phytophthora (from Greek ("phyton"), plant and ("phthora"), destruction; the plant-destroyer) is a genus of plant-damaging Oomycetes (water molds), whose member species are capable of causing enormous economic losses on crops worldwide, as well as environmental damage in natural ecosystems. The cell wall of" Phytophthora" is made up of cellulose. The genus was first described by Heinrich Anton de Bary in 1875. Approximately 100 species have been described, although 100500 undiscovered "Phytophthora" species are estimated to exist. - Chlorella is a genus of single-cell green algae belonging to the phylum Chlorophyta. It is spherical in shape, about 2 to 10 m in diameter, and is without flagella. "Chlorella" contains the green photosynthetic pigments chlorophyll-a and -b in its chloroplast. Through photosynthesis, it multiplies rapidly, requiring only carbon dioxide, water, sunlight, and a small amount of minerals to reproduce. - Kelps are large seaweeds (algae) belonging to the brown algae (Phaeophyceae) in the order Laminariales. There are about 30 different genera. - Spirogyra (common names include water silk, mermaid's tresses, and blanket weed) is a genus of filamentous charophyte green algae of the order Zygnematales, named for the helical or spiral arrangement of the chloroplasts that is diagnostic of the genus. It is commonly found in freshwater areas, and there are more than 400 species of "Spirogyra" in the world. "Spirogyra" measures approximately 10 to 100m in width and may grow to several centimeters in length. - A eukaryote (or or ) is any organism whose cells contain a nucleus and other organelles enclosed within membranes. Eukaryotes belong to the taxon Eukarya or Eukaryota. The defining feature that sets eukaryotic cells apart from prokaryotic cells (Bacteria and Archaea) is that they have membrane-bound organelles, especially the nucleus, which contains the genetic material and is enclosed by the nuclear envelope. The presence of a nucleus gives eukaryotes their name, which comes from the Greek ("eu", "well" or "true") and ("karyon", "nut" or "kernel"). Eukaryotic cells also contain other membrane-bound organelles such as mitochondria and the Golgi apparatus. In addition, plants and algae contain chloroplasts. Eukaryotic organisms may be unicellular or multicellular. Only eukaryotes form multicellular organisms consisting of many kinds of tissue made up of different cell types. - Oomycota or oomycetes form a distinct phylogenetic lineage of fungus-like eukaryotic microorganisms. They are filamentous, microscopic, absorptive organisms that reproduce both sexually and asexually. Oomycetes occupy both saprophytic and pathogenic lifestyles, and include some of the most notorious pathogens of plants, causing devastating diseases such as late blight of potato and sudden oak death. One oomycete, the mycoparasite "Pythium oligandrum", is used for biocontrol, attacking plant pathogenic fungi. The oomycetes are also often referred to as water molds (or water moulds), although the water-preferring nature which led to that name is not true of most species, which are terrestrial pathogens. The Oomycota have a very sparse fossil record. A possible oomycete has been described from Cretaceous amber. - Algae (singular "alga" ) is an informal term for a large, diverse group of photosynthetic organisms which are not necessarily closely related, and is thus polyphyletic. Included organisms range from unicellular genera, such as "Chlorella" and the diatoms, to multicellular forms, such as the giant kelp, a large brown alga which may grow up to 50m in length. Most are aquatic and autotrophic and lack many of the distinct cell and tissue types, such as stomata, xylem, and phloem, which are found in land plants. The largest and most complex marine algae are called seaweeds, while the most complex freshwater forms are the Charophyta, a division of green algae which includes, for example, "Spirogyra" and the stoneworts. Given the information, choose the subject and object entities that have the relation of 'taxon rank'.
The answer to this question is:
dictyochales , class