| environ. |
diatom Unicellular algae, some of which are colonial, green or brownish in colour (but all contain chlorophyll) and with siliceous and often highly sculptured cell walls. Diatoms make up much of the producer level in marine and freshwater food chains, and they have contributed to the formation of oil reserves. Deposits of diatomaceous earths were formed by the accumulation of diatom cell walls (单细胞藻类。 其中一些是无性的，颜色为绿色或褐色(但都含叶绿素)，含有硅质的细胞壁呈高塑性。 硅藻在海水和淡水食物链中处于生产者阶层，他们有助于石油储备的形成，硅藻细胞壁的聚集造成了硅质土的沉积。) |
