Diatoms By, Jase Franke

Scientific Classification Domain: Eukaryote Kingdom: Chromalveolata Phylum: Heterokontophyta Class: Bacillariophyceae

What Are Diatoms? Diatoms are unicellular organisms that have a glassy covering composed of two parts of called frustules (hydrated silicon dioxide), one larger and one smaller that fit together like a box. They are one of the most common phytoplankton.

Facts They are the producers in food chain. Their cell wall is made of silica. Fossil evidence shows that they may have originated during the Jurassic Period.

Reproduction When the diatoms reach a certain size they reproduce asexually. The gametes shed their frustules and fertilize each other, forming a zygote. The Zygote continually grows before forming new frustules.

Facts When Diatoms die, their frustules sink and accumulate on the bottom of the sea. Over time, the frustules form into sedimentary rock. Over time, geological events have caused these deposits to surface on land. This is called diatomaceous earth.

Pennate diatoms (Pennales) An order of diatoms (Bacillariophyceae) in which their form is often circular, and the markings on the valves are radial. Pennales are apart of the Diatom species. The order is named for the shape of their cell walls.

Pennate Diatoms (Pennales) They are producers. They are also one of the most common phytoplankton.