The organisms of this group exhibit holozoic,saprophytic,and some parasitic modes of nutrition.

Which of the following parasites causes the disease known as $Sleeping \text{ } Sickness$?

Animals of class $Ciliata$ (Ciliates):

Which organism is structurally and functionally unicellular?

Diatoms are not easily destroyed like other algae because-

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