Suppose you accidentally find an old preserved permanent slide without a label

Suppose you accidentally find an old preserved permanent slide without a label. In your effort to identify it, you placed the slide under microscope and observed the following features :
(a) Unicellular
(b) Well defined nucleus
© Biflagellate-one flagellum lying longitudinally and the other transversely.
What would you identify it as ? Can you name the kingdom it belongs to ?

As the organism is unicellular with a well defined nucleus it must be a member of Kingdom Protista. Presence of two flagella one lying longitudinally and the other transversely is the characterstic of dinoflagellates. So it is a dinoflagellate.