text: In many of these organisms, flagella are covered by lateral hairs called mastigonemes.
full_question: In many of these organisms, flagella are covered by lateral hairs called mastigonemes. Duringcytokinesis, some of these organisms form "pit connections" and "pit plugs." A grouping of theseorganisms receives buoyancy from gas-filled structures called pneumatocysts (emphasize the "U" sound).Chlorophyte and charophyte ones possess both the a and b forms of chlorophyll. Most heterokonts arethese organisms. They produce the polysaccharide (*) agarose, and like Cyanobacteria, they can causediscolorations of water known as "blooms." They range in size from the tiny phytoplankton diatoms to the massivegiant kelp. For 10 points, name these protists that come in brown, green, and red types.
first_sentence: In many of these organisms, flagella are covered by lateral hairs called mastigonemes.
raw_answer:  algae [prompt on protists; prompt on phytoplankton; accept heterokonts until mentioned; accept specific types of algae, such as brown algae or green algae or red algae]