Cannot remove Captcha Q&A custom field after plugin removed

I installed buddypress and the buddypress captcha plugin in which i created a question/response field in the plugin...due to some positioning issues on the registration page i deleted the captcha plugin but the question/answer response is stil there! and its merging in with my terms and conditions plugin. i have searched all my custom fields and cannot find where i can delete the captcha field. please help. thanks