In the history of cell biology, which set correctly lists the three core tenets of classical cell theory?

• A. Cells are the smallest unit of heredity; all cells use oxygen for respiration; new cells form only during embryonic development.
• B. All living organisms are composed of one or more cells; the cell is the basic unit of structure and function in living things; all cells arise from pre-existing cells.
• C. All cells contain a nucleus; all organisms are multicellular; cells arise spontaneously from nonliving matter.
• D. All cells have identical organelles; the cell membrane is the site of DNA replication; all cells arise from pre-existing tissues.

Answer: (B)