chryosophytes
22.11.4 Chryosophytes Chryosophytes are the most abundant unicellular algae in the oceans. They are also one of the biggest components of plankton, a free-floating collection of microorganisms, eggs, and larvae. As photosynthetic organisms, they produce a significant amount of atmospheric oxygen. The reproduction cycle of chryosophytes is particularly interesting. Note that diatoms reproduce both asexually and sexually. Since diatoms have a rigid cell wall with an outer layer of silica found in sand and glass , the daughter cells produced by mitosis must fit inside the original cell wall. Therefore, each generation of diatoms is smaller than the one before. The reduction in size continues until the diatoms produce sexually, producing a zygote which eventually grows to the original size as it matures.