The morpheme gluco means

• A. Glucose
• B. Tongue
• C. Knowledge
• D. Written, recording

Answer: (A)

Gluco- is a combining form that means sugar. It flags terms related to sugar in the body, such as glucose, glycolysis, and glycemia. Since the question asks for what the morpheme gluco denotes, the term that directly uses this root to refer to the sugar itself is glucose. The other options point to different roots (tongue, knowledge, written/recording), so they don’t fit the meaning of gluco.