Which statement about prokaryotic cells is true?

• A. They have a true nucleus enclosed by a nuclear envelope.
• B. They generally lack a membrane-bound nucleus.
• C. They are always larger than eukaryotic cells.
• D. They contain chloroplasts for photosynthesis.

Answer: (B)

Prokaryotic cells do not have a membrane-bound nucleus. Their genetic material sits in a nucleoid region that is not separated from the rest of the cell by a nuclear envelope. This contrasts with eukaryotic cells, which have a true nucleus enclosed by a nuclear membrane. That fundamental distinction makes the statement true: prokaryotes generally lack a membrane-bound nucleus.

Understanding this helps explain why the other ideas aren’t accurate for prokaryotes. A true nucleus enclosed by a nuclear envelope is a hallmark of eukaryotic cells, not prokaryotic ones. Prokaryotic cells are typically smaller than most eukaryotic cells, not larger. Chloroplasts, the sites of photosynthesis, are organelles found in plant and some algal cells (eukaryotes), not in prokaryotes—though some bacteria can perform photosynthesis without chloroplasts.