gpas with recruitment

1.) do sororitys look at your high school GPA?
2.) I know they obviously look at your GPA from first semester, but how is it taken into account? I know they all have minimum GPA requirements. Are they just cutting people who are below that, or specifically looking for people who are well above that? So like, if a sorority has a minimum GPA of 2.7, are they really looking for a girl who has a 3.5, or are they just cutting all the girls who are below?
3.) how much is difficulty of classes taken into account? is a type-a premed student more competitive than a more liberal arts/humanities person who's also involved in a lot of activities on grounds?