Which of the following is not true for $Euglena$?

$Entamoeba$ differs from $Amoeba$ in not having:

Characteristic spores of diatoms are

Which of the following organisms possesses two nuclei?

Two species of Amoeba $X$ and $Y$ were kept in fresh water and adapted to it. Species $X$ developed a contractile vacuole. When both were transferred to sea water and adapted, both $X$ and $Y$ lost their contractile vacuole. From these observations, we conclude that:

Select the correct option for the following statements:
$(i)$ The sea appears red or golden when red dinoflagellates multiply rapidly.
$(ii)$ $Euglena$ / $Slime$ $molds$ are saprophytic protists.