Question

Siliceous frustules of diatoms being indestructible, piled up at the bottom of ocean and formed a thick bed over billions of years. Such a thick bed is known as

• A. red sea
• B. diatomaceous earth
• C. pseudorocks
• D. red tides

Answer 1

The correct option is B diatomaceous earth

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. Thus, diatoms have left behind large amount of cell deposits in their habitat; this accumulation over billions of years is referred to as 'diatomaceous earth'.

So the correct option is "diatomaceous earth".