Cells are the basic units of structure and function in living things. They are the smallest units of living that show the characteristics of life. There are two basic types of cells, Those with nuclei (eukaryotic) and those without (prokaryiotic). All of the cells in a human are eukaryotic. They have many specialized internal structures calle organelles. Some organelles are enclosed in a membrane and others aren't. The main ones are covered in these pages.
Back to Biology Home Page