Humor writing is a piece of fiction or nonfiction written with the express purpose of being funny. How it strikes a humorous chord and the resulting laughs (or groans) it produces depends on the piece. For example, a piece may be satirical without necessarily being laugh-out-loud funny.
A cell wall is a structural layer surrounding some types of cells, just outside the cell membrane. It can be tough, flexible, and sometimes rigid. It provides the cell with both structural support and protection, and also acts as a filtering mechanism.
