biology

Planktosphaeria

Planktosphaeria is a biology 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 Planktosphaeria rather than just read about it. In short: Planktosphaeria is a genus of Chlorophyceae of the green algae. It was first described by the phycologist Gilbert Morgan Smith in 1918, with Planktosphaeria gelatinosa as its type species.

Key takeaways

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

Reference excerpt

Planktosphaeria is a genus of Chlorophyceae of the green algae. It was first described by the phycologist Gilbert Morgan Smith in 1918, with Planktosphaeria gelatinosa as its type species. Species of Planktosphaeria are commonly found in freshwater plankton around the world.

Description Planktosphaeria consists of solitary cells or in clusters of 8 to 16. Cells are spherical, usually surrounded by a layer of mucilage, sometimes with multiple layers. Young cells have a single chloroplast with a pyrenoid. Mature cells have numerous angular chloroplasts that are parietal, with one or several pyrenoids. Distinguishing Planktosphaeria from other nonmotile coccoid, spherical algae is difficult. Often, Planktosphaeria forms loose ring-like aggregations shortly after vegetative reproduction; when this happens, the mother cell wall may remain, which is a useful identification trait.

Taxonomy The taxonomy of Planktosphaeria has been muddled in confusion, particularly with regards to the similar genus Follicularia. Follicularia is a genus that produces zoospores, while Planktosphaeria was characterized by reproduction via autospores only. The phycologist Richard C. Starr redefined Planktosphaeria to include Follicularia and subsequently described several species under the name Planktosphaeria; all of these were isolated from soil samples and produced zoospores. Phylogenetic analysis of the strains isolated by Starr has revealed that zoospore-producing "Planktosphaeria" species were separate from autospore-producing algae, and therefore the name Follicularia has been reapplied to zoospore-producing algal strains. However, zoospore-producing "Planktosphaeria" are also polyphyletic, with the strains falling into two separate clades. Strains from one clade were reclassified in a new genus, named Herndonia. The nature and classification of "true" Planktosphaeria gelatinosa is still uncertain, because no authentic strain of Planktosphaeria gelatinosa matching the genus-level characteristics exists.

References

External links AlgaeBase AlgaTerra database Index Nominum Genericorum

Illustrations

Worked examples

Example 1 — a first encounter with Planktosphaeria

Start with the simplest possible case. Write down what Planktosphaeria claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In biology, 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 Planktosphaeria 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 Planktosphaeria 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 Planktosphaeria

In research: Planktosphaeria appears in biology 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 Planktosphaeria 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: Planktosphaeria is common in secondary-school and first-year university syllabi. It links to neighbouring topics Chlorophyceae stubs, Freshwater algae, Sphaeropleales, so understanding it makes those chapters shorter.
In everyday life: Look for Planktosphaeria 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 Planktosphaeria in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Planktosphaeria 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 Planktosphaeria out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Planktosphaeria in simple terms?

Planktosphaeria is a genus of Chlorophyceae of the green algae. It was first described by the phycologist Gilbert Morgan Smith in 1918, with Planktosphaeria gelatinosa as its type species.

Why does Planktosphaeria matter?

Because it connects several biology 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 Planktosphaeria?

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 Planktosphaeria.