For PhD, you have to go to Grad. School. UG is just a step that has to be completed. UG will not prepare one for the carrer of scientists. I would think that just as with Med. School, it is not important where you attend for your UG, but what you as a student and person will do there, what opportunities you will not neglect, and opprotunites are absolutely everywhere. actually at schools that are supposed to be “top”, you will find many lectures are not taught by profs. So, what is a point in the fact that class is taught by world-renowned schientist? On the other hand, there are UGs with less recognized names where you find tha oficial policy is that all lectures are actually given by profs, not TA’s that focus on the undergrads and their research opportunities and that would be an indication of the better school for the UG. But still, the responsibilites are on the student schoulders and not on the insitution. So, from what I can tell based on personal experience, choose the school that you personally prefer to attend and do it after very careful research of the place and not on rankings.