Biology: Concepts and Investigations 2nd Edition by Mariëlle Hoefnagels

Exercise 31

A researcher removes a tumor from a mouse and breaks it up into individual cells. He injects each cell into a different mouse. Although all of the mice in the experiment are genetically identical and were raised in the same environment, they develop cancers that spread at different rates. Some mice die quickly, some linger, and others recover. What do these results indicate about the cells that made up the original tumor?