Answer: Diatoms have a cell wall that includes silica, while dinoflagellates have a cell wall that includes cellulose.
Step-by-step 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.