Example of form follows function in cell biology

Example: human's arm and bat's wing share the same evolutionary origin and exhibit similar internal anatomical structures, but they have different forms because these structures have different functions

Explanation:  

The idea "Form Follows Function" indicates that the form/shape of a structure is directly associated with the function of that structure. The relation form-function is a consequence of the evolutionary process. Thus, in different species, analogous structures that share the same evolutionary origin can have different forms and/or shapes because they perform distinct functions, such as in the example above.