Which observation most strongly indicates that a cell is a eukaryote rather than a prokaryote?

• A. The cell uses DNA as its genetic material.
• B. The cell contains a membrane-bound nucleus enclosing its DNA.
• C. The cell has a plasma membrane surrounding the cytoplasm.
• D. The cell contains ribosomes for protein synthesis.

Answer: (B)

Verified step by step guidance

1. Understand the key differences between prokaryotic and eukaryotic cells. Prokaryotes lack membrane-bound organelles, while eukaryotes have them, including a nucleus.
2. Identify the significance of a membrane-bound nucleus: it encloses the DNA within a distinct compartment, which is a hallmark of eukaryotic cells.
3. Evaluate each observation: using DNA as genetic material, having a plasma membrane, and containing ribosomes are features common to both prokaryotes and eukaryotes.
4. Recognize that the presence of a membrane-bound nucleus enclosing DNA is unique to eukaryotes and thus is the strongest indicator that a cell is eukaryotic.
5. Conclude that the observation 'The cell contains a membrane-bound nucleus enclosing its DNA' most strongly indicates a eukaryotic cell.