In which organism is silica present in the cell wall?

Microfossils often present in petroleum-producing formations are those of:

$A$: Holophytic protistans are important phytoplanktons and they contribute $80\%$ of the total photosynthesis.
$R$: They lack chemosynthetic nutrition and utilize non-sulphur organic compounds as the source of electron and proton in carbon assimilation.

Which protozoan possesses a whip-like flagellum?

What is common among $Trypanosoma$,$Noctiluca$,$Monocystis$,and $Giardia$?

$A$: Slime moulds have the characters of both plants and animals.
$R$: Reproductive phase is animal-like and vegetative phase is plant-like.