Which option best summarizes the three classic tenets of the original cell theory in the history of cell biology?

• A. Cells are composed primarily of DNA; the nucleus is the control center of the cell; and mitochondria are the site of photosynthesis.
• B. All living organisms are composed of one or more cells; the cell is the basic unit of structure and function in living things; and all cells arise from pre-existing cells.
• C. All cells contain membrane-bound organelles; the ribosome is the basic unit of life; and all cells arise only by spontaneous generation.
• D. All organisms are composed of tissues; tissues are the basic unit of life; and new tissues arise spontaneously from nonliving material.

Answer: (B)