Which of the following statements best summarizes the most important principles of the cell theory?

The statement that cells arise from older, preexisting cells and are fundamental to all living organisms encapsulates the core tenets of cell theory. Cell theory, established in the mid-19th century by pioneers like Schleiden, Schwann, and Virchow, emphasizes that all living things are composed of cells, which are the basic units of life. This principle highlights that new cells originate from the division of existing cells, indicating a continuity of life and the importance of cellular replication in growth, development, and reproduction.

Additionally, the concept that cells are fundamental to all living organisms emphasizes their universal role as the building blocks of life, applicable to both unicellular and multicellular organisms. This understanding is crucial in fields ranging from biology to medicine, as it sets the foundation for how organisms function and interact.