Ed---
I see you are having more trouble than most admitting we have much to learn about sexuality in the year 2012.
You are hating even the "possibility" that you could be wrong and the Bible is over-stating the nature of male and female as if it were a clear either/or.
If your professor heard you in class stumbling around as you spoke, he was probably telling your the truth: There is "'knowledge" and there is "understanding." Sometimes the two are not one and the same.
The scientific method requires some hypothesis and then studies to prove or disprove them. Even the studies can land you where you began and, too often, even scientists try to prove themselves to be accurate with fake studies.
Some things just remain a mystery and have no clear answer. I see the homosexual thing as such.