Note: It is also classified in protozoa due to its holozoic mode of nutrition and colourless body.
➤ Structure
➤ Reproduction
Note: Exceptionally Noctiluca is diploid so it reproduce by gametic meiosis, therefore its life cycle is Diplontic type.
Note: Their cell wall has silica in very large quantity. Due to this reason, their cell wall is hard. The cell wall does not get destroyed after their death so, at the bottom of the sea, very huge rocks of dead diatoms are formed which are known as "diatomite" or "diatomaceous earth" or "kieselguhr".