Atoms combine to form molecules. Different atom combinations create different molecular structures with specific functions.
Molecules combine to form organelles which are the structures that make up cells such as the nucleus.
A tissue is a group of cells that have similar functions and characteristics. 4 basic classifications- epithelial, connective, muscle, and nervous.
Composed of two or more tissue types that perform one or more common function(s). They work together for a specific purpose.
A group of organs that work together to perform a common function (11 different types).