They are important food Web of marine ecosystem. They look like pearls after their death when their empty cell wall fall in the bottom of the water body and form diatomaceous earth. Hence it is called so,..... Please give it the best...................
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The diatoms- the unique organisms - are sometimes called the jewels of the sea because of the distinctive cell walls. The cell wall of diatoms is chiefly composed of cellulose impregnated with glass like silica. It shows sculpturing and ornamentations. That is why, diatoms are also called as 'pearl of ocean'.

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