- Cell division increases the number of cells in an organism.
- Growth increases the size of individual cells.
- Differentiation is the process by which cells become specialized in structure and function.
During development, a single zygote (fertilized egg) divides through mitosis to produce two cells, then four cells, then eight cells, and so on. As the number of cells increases, the cells also grow in size. At a certain point, the cells begin to differentiate. Some cells become skin cells, others become muscle cells, others become nerve cells, and so on.
The result of cell division, growth, and differentiation is a multicellular organism with a highly organized structure and function.
