Botany - Biological Classification Question with Solution | TestHub

In diatoms, the cell walls form two thin overlapping shells, which fit together as in a soapbox. The walls are embedded with silica and thus, the walls are indestructible. Hence, diatoms have left behind a large amount of cell wall deposits in their habitat; this accumulation over billions of years is referred to as ‘diatomaceous earth’. Being gritty, this soil is used in polishing, filtration of oils and syrups.