Page 16 - Kingdom Protist
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Figure 3.3 Diatoms reproduce asexually for several generations before undergoing
sexual reproduction.
Dinoflagellates Plantlike protists that are members of the phylum Pyrrophyta are
called dinoflagel lates. Most members of the phylum are unicellular and have two
flagella at right angles to one another. As these flagella beat, a spinning motion is
created, so dinoflagellates spin as they move through the water. Some members in
this group have cell walls made of thick cellulose plates that resemble helmets or suits
of armor. Other members of this group are bioluminescent, which means they emit
light. Although there are a few freshwater dinoflagellates, most are found in
saltwater. Like diatoms, photosynthetic dinoflagellates are a major component of
phytoplankton. Dinoflagellates vary in how they get their nutritional requirements.
Some dinoflagellates are photosynthetic autotrophs, and other species are
heterotrophs. The heterotrophic dinoflagellates can be carnivorous, parasitic, or
mutualistic. Mutualistic dinoflagellates have relationships with organisms such as
jellyfishes, mollusks, and coral.
Review Vocabulary
Pyrrophyta: pyro– prefix; from Greek; meaning fire.
–phyton from Greek word phyton, meaning plant.
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