Virchow stated that all cells come from preexisting cells.

• A. Cells come from preexisting cells
• B. All organisms are made of cells
• C. Cells are the basic unit of life
• D. The nucleus is the control center of the cell

Answer: (A)

The essential idea being tested is how new cells arise. Virchow’s idea—the statement that all cells come from preexisting cells—captures the mechanism of cell formation: cells divide to create new cells, rather than appearing out of nowhere. This explains how growth, tissue repair, and development occur at the cellular level and is a specific assertion of cell theory.

That’s why the phrase about cells coming from preexisting cells is the best fit. The other statements describe important aspects of cell theory—like all organisms being made of cells or cells being the basic unit of life—but they don’t address how new cells originate. The note about the nucleus as the control center is an older, more simplified view of cell function and doesn’t relate to the origin of cells.