Coscinodiscophyceae

In terms of cell cycle, vegetative cells are diploid and undergo mitosis during normal cell division. In sexual species, oogamous meiosis produces haploid gametes, either ova or sperm cells. These fuse to produce a zygote which expands in size to develop into an auxospore from which full-sized vegetative cells are produced.

In some taxonomy schemes, the centric diatoms are known instead as order Coscinodiscophyceae, and in some schemes as order Biddulphiales. However, diatom taxonomy is changing due to the development of new molecular and genetical analysis tools.