Flexi Says: A cell is the smallest basic living unit of all organisms. Organisms can be unicellular or multicellular, which means that they can be made up of one cell or more than one cell. Some cells in the human body include neurons (nerve cells), leukocytes (white blood cells), and adipocytes (fat cells). A tissue is an aggregate of cells that work together in order to perform a specific function. The four major classes of tissues are connective, epithelial, muscular, and nervous tissues, which all have their own subgroups.
