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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
Their cell wall is… (297 more words) …
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Mainly asexual - binary fission.
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:
- Sound proofing
- Filtration of oils and syrups
- Stone polishing
- As “Heat insulator” in steam boilers i. e. they are used as thermostat because the kieselguhr bad conductor of heat.