(N/A) $\rightarrow$ Habitat: These organisms are mostly marine and photosynthetic.
$\rightarrow$ Body organization: They appear yellow,green,brown,blue,or red depending on the main pigments present in their cells.
$\rightarrow$ Cell wall: The cell wall has stiff cellulose plates on the outer surface.
$\rightarrow$ Flagella: Most of them have two flagella; one lies longitudinally and the other transversely in a furrow between the wall plates.
$\rightarrow$ Special features: Very often,red dinoflagellates (e.g.,$Gonyaulax$) undergo such rapid multiplication that they make the sea appear red (red tides). Toxins released by such large numbers may even kill other marine animals such as fishes.
$\rightarrow$ Reproduction: Dinoflagellates reproduce asexually through cell division or by the formation of zoospores and cysts.
$\rightarrow$ Reserve food: Reserve food is stored in the form of starch and oils. Examples include $Gonyaulax$,$Ceratium$,$Noctiluca$,$Peridinium$,and $Gymnodinium$.