I'm confused about TA-ing... is this a course on how to be a TA, or are you just talking about a course you TA-ed? If it is a course you TA-ed, I'm assuming it's not on your transcript and should be listed as work experience instead. If it's a course on how to be a TA, I guess I would probably list it as "education". For the research project, I would classify it as whatever department you did your project in (mine was in biochemistry, so I listed it as "chemistry"). The ethnic studies class sounds like "behavioral and social sciences" to me, but what department taught the class?
If you go into AMCAS and click on the HELP button at the top of the page, then go to "course work", then "course work classifications" on the side toolbar, it lists what courses go with what classification.
