"Diatomite" (Kieselguhr) is obtained from which of the following?

Select the correct statements for Dinoflagellates:
$I -$ Mostly found in freshwater.
$II -$ Photosynthetic.
$III -$ Possess two flagella - one longitudinal and one transverse.
$IV -$ Cell wall has stiff cellulose plates on the outer surface.
$V -$ Dinoflagellates appear in different colors.

In $Amoeba$ and $Paramecium$,osmoregulation occurs through . . . . . . .

Select the correct option for the following statements:
$(i)$ All protozoans are heterotrophs and live as predators or parasites.
$(ii)$ $Trypanosoma$ causes sleeping sickness.

$A$ living $Amoeba$ is:

Which of the following organisms resembles the ancestral form from which both animals and plants are believed to have evolved?