The prefix endo- means which of the following?

The prefix endo- means which of the following?

• A. Outside
• B. Above
• C. Behind
• D. Within

Answer: (D)

Endo- comes from Greek and means inside or within. It’s used in terms like endoscope (an instrument used to look inside), endocardium (the inner lining of the heart), and endoskeleton (an internal skeleton). So when you see endo-, it signals something being inside. That makes the meaning “within” the best fit. The other directional ideas—outside, above, behind—are conveyed by different prefixes (for example, ex- for outside or epi- for above), which is why they don’t match endo- as closely.

Endo- comes from Greek and means inside or within. It’s used in terms like endoscope (an instrument used to look inside), endocardium (the inner lining of the heart), and endoskeleton (an internal skeleton). So when you see endo-, it signals something being inside. That makes the meaning “within” the best fit. The other directional ideas—outside, above, behind—are conveyed by different prefixes (for example, ex- for outside or epi- for above), which is why they don’t match endo- as closely.