Question

What is the nature of the cell wall in diatoms? What is diatomaceous earth? Mention any two economic uses of it. Name the group under diatoms belongs to Protista.

Answer 1

Hint: Diatom’s leaves have large amounts of cell deposits in their habitat, which accumulates for years and later forms a gritty matter.

Complete Answer:
- Body of diatoms is covered by a transparent siliceous shell which is called frustule. It is composed of valves which fit like a soap box. The siliceous frustules do not get decayed and further get deposited at the bottom of reservoirs and form the heaps which are further termed as diatomaceous earth. It is also known as diatomite. This diatomaceous earth is gritty in texture.
- Diatomaceous earth are chemically inert and thus are used in filtration of sugars, alcohols, etc., as insulating material in refrigerators, boilers, and sources of water glass. They are also known to be good pollution indicators.
- Diatomite are natural nano-particles and have applications such as, production of, construction ceramics, refractory ceramics, various ceramic products and oxide ceramics, production of humidity control materials, filtration material, production of prolonged-release drug carriers material.
- Diatoms belong to the Chrysophytes group of Photosynthetic Protists.

Additional Information: Diatoms occur in all aquatic and moist terrestrial habitats as either bottom dwellers or free floating. They are microscopic and do not possess flagella except in reproductive state. A major portion of the organic matter synthesized on earth is believed to be produced by these photosynthetic diatoms.

Note: Diatoms are not to be confused with the desmids, both belong to Chrysophytes. Diatoms act as good pollution indicators which are indicators of clean water.