Give scientific reasons: Diatoms are called the pearls of the ocean.

Reproduction in $Paramecium$ is controlled by

Which of the following organisms are included in the group Protista?

Marine protozoans lack a contractile vacuole 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?

Which of the following is true for $Trypanosoma$?