I teach high school - But I LOVE inquiry labs.
The first one we do is slime mold and they have to come up with some sort of question about how it will grow.
The questions have to be specific. they also have to really focus on one variable.
slime mold likes - damp, dark and cool. It grows well on agar plates.
students ask questions like
"will slime mold eat flavored oatmeal" or even better "Which type of oatmeal does slime mold prefer - plain, cinnamon rasin, or apple and spice"
There is so much you can do with inquiry labs. It is all about getting the students to ask questions detailed enough to guide thier procedure.
My students moan at first but by the end of the lab they say how much fun it was. I think it really empowers them to answer their own questions