Which prefix means between two structures?

• A. Inter-
• B. Intra-
• C. Para-
• D. Pre-

Answer: (A)

The prefix inter- expresses relationships between two or more structures, meaning “between.” It’s used when something lies or occurs between parts, such as intercellular (between cells), intercostal (between the ribs), and interatrial (between the atria).

This fits the idea of “between two structures” best because other prefixes describe different relationships: intra- means within a single structure (intracellular = inside a cell), para- means beside or near (paranasal = near the nasal cavity), and pre- means before in time or in front of (preoperative = before surgery).