Where does mitosis take place?

• A. Multicellular organisms
• B. Single-celled organisms
• C. Prokaryotic cells
• D. All living cells

Answer: (A)

Mitosis is the division of the nucleus in cells that have a true nucleus (eukaryotic cells). Prokaryotic cells lack a membrane-bound nucleus and divide by binary fission, not mitosis. Among the options, multicellular organisms are the best fit because their many cells routinely undergo mitosis for growth, development, and tissue maintenance. Some single-celled eukaryotes also divide by mitosis, but many single-celled organisms (like bacteria) do not, so the statement that applies to multicellular organisms is the most appropriate here.