Which prefix means Small?

• A. Micro-
• B. Dia-
• C. Bio-
• D. Trans-

Answer: (A)

Size prefixes in medical terminology show how big or small something is. The prefix micro- means small, often indicating something on a very small scale or one millionth in measurement. That’s why it appears in terms like microscope or microgram—they convey tiny size. The other prefixes have different meanings: dia- means through or across, bio- means life, and trans- means across or beyond. None of those indicate small, so micro- is the best fit for “Small.”