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Division - Pyrrophyta - Class Dinophyceae -Dinoflagellates

  • Habitat: Dinoflagellates are marine, they are usually abundant in plankton but some occur in fresh water.

  • Forms: Unicellular, cell wall has stiff cellulose plates on the outer surface. Most of them have two flagella; one lies longitudinally and the other transversely in a furrow between the wall plates.

  • Nutrition: Photosynthetic and reserve food is starch and oil.

Note: In Dinoflagellates, the nutrition is mainly holophytic (photosynthetic), because they have chloroplast.

Examples of dinoflagellates –

Noctiluca, Ceratium, Gonyaulax, Gymnodinium, Pyrocystis

Image showing examples of dinoflagellates.

Image Showing Examples of Dinoflagellates.

Noctiluca, Ptychodiscus, Ceratium and Gonyaulax are the examples of dinoflagellates.

Structure:

  1. Their cell wall is… (297 more words) …

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Reproduction

  1. Mainly asexual - binary fission.

  2. Sexual reproduction - Very rare - by gametic meiosis.

Note: The zygote formed during sexual reproduction is called as “Auxospore”. Auxospore is an asexual structure.

Use of Diatoms:

  1. Sound proofing
  2. Filtration of oils and syrups
  3. Stone polishing
  4. As “Heat insulator” in steam boilers i. e. they are used as thermostat because the kieselguhr bad conductor of heat.
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