How come on prison break Michael and Link have different last names?

Question

How come on prison break Michael and Link have different last names?

Answer 1

This was explained in season 1.

Their father abandoned the family when their mother was pregnant with Michael.  She filed for divorce and went back to her maiden name (Scofield), and gave Michael that surname when he was born.

Answer 2

both have the same mother and father but Michael uses his mother maiden  name and lincoln uses his fathers last name.

After his father deserted the family, Michael Scofield took up his mother's maiden name in order to start a new life because his mother told him that his father, Aldo Burrows was addicted to alchohol.[1] After their mother's death from liver cancer, Lincoln became his guardian and took care of him.  

Answer 3

Different fathers?

One of them changed their name possibly. Example: Charlie Sheen and Emilio Estevez are brothers and have different last names.