The Prototype design pattern is all about cloning an object. Mitosis, the process in a cell division by which the nucleus divides resulting in two new nuclei, each of which has exactly the same chromosome and DNA content as the original cell, is an example of biological cloning [j.mp/mmitosis].
The following figure, provided by www.sourcemaking.com, shows an example of the mitotic division of a cell [j.mp/pprotpat]:
Another popular example of (artificial) cloning is Dolly, the sheep [j.mp/wikidolly].