In mathematics, especially in set theory, a setA is a subset of a set B, or equivalently B is a superset of A, if A is "contained" inside B, that is, all elements of A are also elements of B. A and B may coincide. The relationship of one set being a subset of another is called inclusion or sometimes containment.
A flagellate is an organism with one or more whip-like organelles called flagella. Some cells in may be flagellate, for instance the spermatozoa of most phyla. do not produce flagellate cells, but , , green algae, some gymnosperms and other closely related plants do. Likewise, most fungi do not produce cells with flagellae, but the primitive fungal do. Many take the form of single-celled flagellates.