Which of these word root indicates bone?

Word roots for organs
Stomato = mouth stomatitis
Salpingo = uterine tubes hysterosalpingogram
Dermo = skin dermatitis
Masto/mammo = breast mammography, mastectomy
Osteo = bones osteoporosis

Which prefixes mean undo?

For example, consider the prefix de-. This prefix means to undo something and is usually attached to a verb.