Biological Classification - Protista: Dinoflagellates, Chrysophytes, and Euglenoids

Vocabulary review covering key characteristics, structures, pigments, and examples of Dinoflagellates, Chrysophytes, and Euglenoids from Chapter 2 Biological Classification.

Dinoflagellates

Mainly marine, photosynthetic protists having cell walls divided into stiff plates, starch as stored food, and two flagella (transverse and longitudinal) that move like whirling whips.

Red tide

The rapid multiplication and spread of dinoflagellates (such as Gonyaulax) across the surface of sea water, responsible for water blooms.

Bioluminescence (Dinoflagellates)

Light emission exhibited by night algae/fire algae dinoflagellates, specifically Noctiluca and Gonyaulax.

Gymnodinium & Gonyaulax

Dinoflagellates that release toxins capable of killing other marine animals, such as fishes.

Chrysophytes

A group of protists comprising diatoms and desmids found in fresh and marine water, which float passively on the surface as plankton and serve as chief producers in the ocean.

Diatom cell wall

A structure consisting of two thin overlapping shells made up of cellulose embedded with silica that fit together like a soap box.

Diatomaceous earth (keiselgurh)

An accumulation of diatom cell wall deposits over billions of years, utilized in stone polishing and the filtration of oils and syrups.

Leucosin (Chrysolaminarin) & fats (Oil)

The stored food reserves found in chrysophytes.

Chrysophyte pigments

Chlorophyll 'a', 'c', and xanthophyll (fucoxanthin).

Pellicle

A protein-rich layer present in euglenoids that replaces the cell wall.

Contractile vacuole (Euglenoids)

An organelle in euglenoids that helps in osmoregulation.

Mixotrophic nutrition

The nutritional mode of euglenoids: photosynthetic (autotrophic) in the presence of sunlight, and heterotrophic when deprived of sunlight.

Euglenoid flagella

Two flagella consisting of one long active flagellum and one short inactive flagellum.

Euglenoid pigments

Chlorophyll 'a', Chlorophyll 'b', and xanthophyll (Zeaxanthin), which are identical to higher plant pigments.

Paramylum and fat

The stored food substances in euglenoids.