The prefix mast(o)- relates to which tissue?

• A. Breast tissue
• B. Lower jaw bone
• C. Upper jaw bone
• D. Destruction

Answer: (A)

The prefix mast(o)- designates breast tissue. It comes from Greek roots meaning breast, and appears in terms like mastitis (inflammation of breast tissue), mastectomy (removal of the breast), and the word mammary gland. A related bone term, mastoid, uses the same root but refers to a bone behind the ear whose name reflects a breast-like shape rather than labeling breast tissue itself. So, when the prefix mast(o)- is used, it points to breast tissue. The other options refer to jaw bones or to destruction and do not align with this prefix.