The "frustule" cell wall of diatoms. A dinoflagellate isn't constructed this way. The frustule is composed of two parts which are pretty much identical except for size -- one of the parts is slightly smaller than the other.
Cell mutation could be a possible option
Answer:
The soils with earthworms will show a faster rate of ammonification
Explanation:
Originally, the nitrogen released by organisms when they die (or excrete waste products) is organic nitrogen, e.i., amino acids and nitrogenous bases in DNA. Ammonification is the property that decomposer organisms have to mineralize organic nitrogen in order to produce inorganic nitrogen in the form of ammonium (NH4+). In agroecosystems, earthworm activity can increase the ammonification rate. For example, <em>Lumbricus terrestris</em> is an invasive earthworm (which is native to Europe) that has been shown to increase both ammonification and nitrification (nitrate production) rates in the soil of different ecosystems.
Natural selection? I'm not sure
