Which of the following statements correctly contrasts prokaryotic and eukaryotic cells?

• A. Prokaryotes lack a nucleus and membrane-bound organelles, are usually smaller, and divide by binary fission; eukaryotes have a nucleus and membrane-bound organelles, are larger, and divide by mitosis.
• B. Prokaryotes have a nucleus; eukaryotes do not.
• C. Prokaryotes and eukaryotes are the same in size and division method.
• D. Eukaryotes lack membrane-bound organelles.

Answer: (D)

Understanding the difference between prokaryotic and eukaryotic cells is about how cell structure relates to function. Prokaryotes organize their genetic material in a nucleoid region, lack a true nucleus and membrane-bound organelles, and are usually smaller; they typically reproduce by binary fission. Eukaryotes have a true nucleus enclosed by a nuclear membrane and contain many membrane-bound organelles such as mitochondria and, in plants and algae, chloroplasts; they are generally larger and divide by mitosis for growth and tissue renewal (with meiosis for sexual reproduction). Because eukaryotic cells do have membrane-bound organelles, the statement claiming they lack them isn’t correct.