<P> Alex secured a position in the surgical residency program at Seattle Grace Hospital after graduating from the University of Iowa . He initially makes a poor impression on his fellow interns meeting fellow interns Meredith Grey (Ellen Pompeo), Cristina Yang (Sandra Oh), George O'Malley (T.R. Knight), and Izzie Stevens (Katherine Heigl) whom he later taunts when he discovers she used to be a lingerie model . After initial disagreements, Alex reveals to Izzie that his father was a heroin addict who used to beat his mother . He became a wrestler so he could defend his mother, and attended university on a wrestling scholarship . He and Izzie begin a friendship . At the end of the first season, George contracts syphilis from Alex through nurse Olivia Harper, causing animosity between the two . </P> <P> Alex asks Izzie out on a date, but he is thrown by the news that he has failed his medical board exams . Izzie is offended since he pays no attention to her during their date and so informs him that she no longer wants to go out with him . He later freezes during an emergency operation, needing George to take over from him . Alex's relationship with Izzie is damaged when he experiences erectile dysfunction with her . He goes on to sleep with Olivia again, and is caught by Izzie and they break up . After retaking his exams, Alex manages a pass, and reunites with Izzie after a bomb scare in the hospital . They break up again, however, when Izzie falls for cardiothoracic patient Denny Duquette . </P> <P> Alex helps Izzie recover from Denny's death and advances Izzie but Izzie backs away since she is still in the process of getting over her loss and they remain friends . Alex spends a period of time working under neonatal surgeon Dr. Addison Montgomery (Kate Walsh), and though he is later released to work for plastic surgeon Dr. Mark Sloan (Eric Dane), he finds his interest returning to Addison's firm . Addison is attracted to Alex, and the two share a kiss and later sleep together . In the aftermath of a ferry accident, Alex rescues a pregnant woman (Elizabeth Reaser) who awakes with amnesia, and grows close to Alex as he helps her forging an identity for herself, picking out the name Ava . After she gives birth to her daughter, Ava's memory eventually returns, although she tries to hide it from Alex as she had recently left a bad marriage . He convinces her to tell him her true identity, and she reveals herself to be Rebecca Pope . Alex turns her down after realizing she's married, feeling that he is not good enough for her . </P> <P> Rebecca returns and she and Alex sleep together before she goes back to her husband . Alex has a brief relationship with intern Lexie Grey (Chyler Leigh), but chooses to be with Rebecca when she returns and tells him she is pregnant . After Rebecca attempted suicide, Izzie convinces Alex to admit her for psychiatric help due to Rebecca's hallucinations of her pregnancy . Alex later breaks down in Izzie's arms, and the two kiss . </P>

When does karev find out rebecca is not pregnant