Who are Bilbo's ancestors? What conflict might this ancestry create for Bilbo?

Bilbo is the only son of Belladonna Took and the Tooks are a wealthy family but Belladonna and a few of the others had adventurous streaks and they were not nearly as respectable as the Bagginses. In this story, Bilbo is going to lose his respectability on a rather wild adventure.

The most important thing to notice here is the juxtaposition of Baggins-like Hobbit-style respectability and Took-ish disregard for convention in favor of adventure. Of course, Bilbo will end up more like his mother, Belladonna Took, but even as "belladonna" means beautiful (woman) it is also a name for a poison.