Question

The progressive diminishing size of diatoms is prevented by the production of

• A. zoospotes
• B. arthrospores
• C. auxospores
• D. basidiospores.

Answer 1

The Correct Option is C

Diatoms have cell walls containing silica, constructed in two overlapping halves epitheca and hypotheca which fit together like two parts of a soap box (pennate types) or pair of Petridishes (centric types) . The common mode of multiplication is by binary fission. During fission, the epitheca and hypotheca slightly separate apart with two daughter protoplasts in between, and new cell wall halves are formed. In case, where parent hypotheca serves as the epitheca for the daughter cell, the resulting daughter cells. become smaller than the parent cell (because in? parent cell hypotheca is smaller than epitheca to fit into it). On the other hand, in case where parent epitheca serves ?as the epitheca, the resulting daughter cell is of the same size as the parent cell. However, fertilization .during sexual reproduction produces a zygote which grows in size and forms a rejuvenescent cell, called auxospore. In, this manner, the diatoms size is restored.