science

Gyrista

Gyrista is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Gyrista rather than just read about it. In short: Gyrista is a clade of stramenopile protists containing three diverse groups: the mostly photosynthetic Ochrophyta, the parasitic Pseudofungi, and the recently described group of nanoflagellates known as Bigyromonada. Members of this clade are characterized by the presence of a helix or a double helix/ring system in the ciliary transition region.

Key takeaways

Gyrista belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Gyrista to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Gyrista from memory before moving on to harder problems.

Reference excerpt

Gyrista is a clade of stramenopile protists containing three diverse groups: the mostly photosynthetic Ochrophyta, the parasitic Pseudofungi, and the recently described group of nanoflagellates known as Bigyromonada. Members of this clade are characterized by the presence of a helix or a double helix/ring system in the ciliary transition region.

Systematics

Taxonomic history Gyrista was first described in 1998 by protistologist Thomas Cavalier-Smith in his work A revised six-kingdom system of life, originally as a superphylum containing two phyla: Ochrophyta, the heterokont algae; and Bigyra, which then contained the pseudofungi and bigyromonads together with the opalines. Later, the name Bigyra was modified to contain opalines, bicosoecids and labyrinthulomycetes, while the Ochrophyta, Pseudofungi and Bigyromonada remained as groups within Gyrista.

Molecular phylogenetics Gyrista was seen in 2017 as the sister group to phylum Bigyra, which contains the Sagenista and Opalozoa. Together, Gyrista and Bigyra form the clade Stramenopiles or Heterokonta.

A phylogenetic analysis in a 2022 preprint recovered a monophyletic Bigyromonada sister to Pseudofungi. The "Bigyra" is paraphyletic:

Classification The 2018 revised taxonomy of Gyrista is the following, with the inclusion of new ochrophyte classes described in 2020 and 2021:

Subphylum Bigyromonada Cavalier-Smith 1998 Class Developea Aleoshin et al. ex Cavalier-Smith 2017 [=Bigyromonadea Cavalier-Smith 1997] Class Pirsonea Cavalier-Smith 2017 Subphylum Pseudofungi Cavalier-Smith 1986 [=Heterokontimycotina M.W. Dick 1976] Class Hyphochytrea Cavalier-Smith 1986 [=Hyphochytriomycota Whittaker 1969] Class Oomycetes Winter in Rabenhorst 1879 [=Oomycota Arx 1967; Peronosporomycetes M.W. Dick 2001] Subphylum Ochrophytina Cavalier-Smith 1995 [=Heterokontophyta van den Hoek et al. 1978; Stramenochromes Leipe et al. 1994] Infraphylum Chrysista Cavalier-Smith 1991 Superclass Limnistia Cavalier-Smith 1996 emend. 2006 Class Eustigmatophyceae Hibberd & Leedale (1971) Class Chrysomonadea Saville-Kent 1881 stat. nov. Pascher 1910 emend. Cavalier-Smith 2017 [=Chrysophyceae Pascher 1914] Class Picophagea Cavalier-Smith 2006 emend. 2017 [=Synchromophyceae Horn et al. 2007] Superclass Raphidoistia Cavalier-Smith 1986 orth. mut. 2006 Class Raphidomonadea Chadefaud ex Silva 1980 Subclass Raphidophycidae Cavalier-Smith 2013 Subclass Raphopoda Cavalier-Smith 2013 Superclass Fucistia Cavalier-Smith 1995 Class Aurophyceae Cavalier-Smith 2013 Subclass Aurearenophycidae Kai Yoshii Nakayama & Inouye 2008 (as Aurearenophyceae) stat. nov. Cavalier-Smith 2013 Subclass Phaeothamniophycidae Andersen & Bailey 1998 (as Phaeothamniophyceae) stat. nov. Cavalier-Smith 2006 Class Chrysomerophyceae Cavalier-Smith 1995 Class Chrysoparadoxophyceae Wetherbee et al. 2019 Class Phaeosacciophyceae R.A.Andersen L.Graf & H.S.Yoon 2020 Class Schizocladiophyceae Henry Okuda & Kawai 2003 Class Phaeophyceae Kjellman 1891 [=Fucophyceae Warming 1884; Melanophyceae Rabenhorst 1863] Class Xanthophyceae Allorge ex Fritsch 1935 [=Tribophyceae Hibberd 1981; Heterokontae Luther 1899] Infraphylum Diatomista Derelle et al. ex Cavalier-Smith 2017 Superclass Hypogyrista Cavalier-Smith 1995 stat. nov. 2006 Class Dictyochophyceae Silva 1980 [=Dictyochia Haeckel 1894; Alophycidae Cavalier-Smith 2006] Subclass Pedinellia Cavalier-Smith 1986 stat. nov. 2017 [=Actinochrysophyceae Cavalier-Smith 1995; Axodines] Subclass Pelagophycidae Andersen & Saunders 1993 (as Pelagophyceae) ex Cavalier-Smith 2006 Class Pinguiophyceae Kawachi et al. 2002 Superclass Khakista Cavalier-Smith 2000 stat. nov. 2017 Class Bolidophyceae Class Diatomeae [=Bacillariophyceae] Subclass Corethrophycidae Round & Crawford 1990 Subclass Rhizosoleniophycidae Round & Crawford 1990 Subclass Eucentricophycidae Cavalier-Smith 2000 Subclass Bacillariophycidae [=Pennatia Pennatia Schütt 1896; =Pennatophycidae] Ochrophytina incertae sedis Class Olisthodiscophyceae Barcytė Eikrem & M. Eliáš 2021

Notes

References

Illustrations

Worked examples

Example 1 — a first encounter with Gyrista

Start with the simplest possible case. Write down what Gyrista claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Gyrista before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Gyrista ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Gyrista

In research: Gyrista appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Gyrista in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Gyrista is common in secondary-school and first-year university syllabi. It links to neighbouring topics Stramenopile taxa, so understanding it makes those chapters shorter.
In everyday life: Look for Gyrista outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Gyrista in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Gyrista means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Gyrista out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Gyrista in simple terms?

Why does Gyrista matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Gyrista?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Gyrista.