8th Grade State Standards: 5.5.A.2. Recognize that complex multicellular organisms, including humans, are composed of and defined by interactions of the following: cells, tissues, organs, and systems.
8th Grade National Standards: All organisms are composed of cells--the fundamental unit of life. Most organisms are single cells; other organisms, including humans, are multicellular.
12th Grade National Standards: Cells can differentiate, and complex multicellular organisms are formed as a highly organized arrangement of differentiated cells. In the development of these multicellular organisms, the progeny from a single cell form an embryo in which the cells multiply and differentiate to form the many specialized cells, tissues and organs that comprise the final organism. This differentiation is regulated through the expression of different genes.