Question

Identify the characteristic features of diatoms.
A. Cell wall is made of pectin, floating on water and producing exospores.
B. Cell wall is made of chitin, fused forms, and produces exospores.
C. Cell walls are made of silica, floating on water, and produce exospores.
D. Cell wall is made of silica, symbolists, and produces zoospores.

Answer 1

Hint: Diatoms are the only organisms on this planet having a transparent, siliceous cell wall. These are actually microscopic algae that inhabit freshwater, saline water, and even soil.

Complete answer:
Diatoms are unicellular, free-living algae.
Some members form filaments, ribbons, or even star-shaped colonies. It has a cell wall made up of transparent, unique silica- often called ‘frustule’.
Diatoms float on water as phytoplanktons and many aquatic animals feed on these.
The specialized cells or spores called exospores are produced by diatoms that grow and develop to regain a normal size.

So, the correct option is C. Cell wall is made of silica, floating on water, and produces exospores.

Note: In diatoms, sexual reproduction also occurs by isogamy and oogamy.
They are able to undergo photosynthetic processes and can store food as oil.