PUBLIC MARKS from fotopol with tags "photographies exceptionnelles" & unicellulaire

What are diatoms? Diatoms are delicate unicellular organisms that have a yellow-brown chloroplast that enables them to photosynthesize. Their cell walls are made of silica almost like a glass house. The construction of the cell wall, called the frustule, consists of two valves that fit into each other like a little pill box.