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.
Answer:
Diatoms have a cell wall that includes silica, while dinoflagellates have a cell wall that includes cellulose.
Explanation:
Diatoms are unicellular algae. Some of them can live in colonies forming filaments or ribbons, they are surrounded by a cell wall made of silica called a frustula.
They are microscopic animals, almost always single-celled. They have flagella. They can be divided into two large groups differentiated by the presence or absence of cellulosic plaques in the cell wall or amphysm.
