Yes.
In fact,
in the 2013 NCAA men's Basketball tournament, the #12 seed beat the #5 seed in three of the four regionals:
California over UNLV 64-61 in the East; Oregon over Oklahoma State 68-55 in the Midwest; and Mississippi over Wisconsin 57-46 in the West.
no one they were not in the tournament.
16 seed, beat duke last year
Marquette was the #16 seed in the NCAA Men's basketball tournament in 1977. They advanced and won the championship. They were also the only team to ever beat all 4 #1 seeds during the ncaa tournament.
Villanova
Iowa State
No, Illinois has never won the NCAA Men's Basketball Tournament.
No they have not.
about 18 or 20 teams.
Rankings are subjective. The NCAA Tournament games are about matchups.
NO
UNC was a number 1 seed in the 2009 NCAA basketball tournament.
Princeton beat UCLA, 43-41 in the first round.