Wage and Labor Law Exemptions

I have been working for a small environmental consulting company in Texas (company gross >$500,000/year) for over one year. During that time, I have had to work a great deal of overtime without any compensation. My employer explained that since I was a "professional", I was exempt from the Federal laws regarding overtime pay. After reading the definition of a professional, I am not sure that I can be considered one. I have a college degree in biology, but have gone no further. Note section 1a of the Federal guidelines (http://www.dol.gov/dol/allcfr/ESA/Title_29/Part_541/29CFR541.3.htm) regarding the definition of a "professional" for labor purposes. The thing that confuses me is this: could my college degree, or even the limited knowledge that I have gained on the job, be seen as "learning customarily acquired by a prolonged course of specialized intellectual instruction", making me exempt from overtime compensation?

Thanks for your help.