Which prefix is used to indicate kidney-related terms?

• A. Nephr(o)
• B. Nas(o)
• C. Ocul
• D. Noct

Answer: (A)

Nephr- (nephr/o or nephro-) is the combining form used to indicate kidney-related terms. It comes from the Greek nephros, and you’ll see it in words like nephrology (study of kidneys), nephron (the kidney’s functional unit), and nephritis (inflammation of the kidney). The other options point to different parts or concepts: nas- relates to the nose, ocul- to the eye, and noct- to night. So when a term is about kidneys, nephr- is the correct prefix to expect.