An aquatic microscopic organism floats passively in water and has a wall formed by two overlapping, silica-containing sh
The organism is a diatom. Diatoms are microscopic plankton whose walls form two thin, overlapping shells embedded with silica. The accumulated deposits of these indestructible walls form diatomaceous earth.
Ref: NCERT Class 11 Biology Chapter 2: Biological Classification Protista - Euglenoids Slime Moulds Protozoans