A scientist is observing a eukaryotic cell and a prokaryotic cell. Which structure could she only observe in the eukaryotic cell?

Eukaryotic cells have a membrane-bound nucleus that contains their DNA. Prokaryotic cells also have cytoplasm, DNA, and ribosomes, but they do not have a nucleus. Therefore, the structure found only in the eukaryotic cell is a nucleus.

AI-written and checked against the verified answer.