Radioisotopes and Life Processes (Revised)

by Walter E. Kisieleski; Renato Baserga

CELL CYCLE AND GENE ACTION: LIFE IS THE SECRET OF DNA

Some circumstantial evidence is very strong, as when you find a trout in the milk.

Henry David Thoreau

For a biologist interested in the mechanism of cell proliferation, the most important event in the life of a cell was, until very recently, cell division. As we mentioned, when a cell divides into two daughter cells, it undergoes a process called mitosis; mitosis itself is subdivided into four stages called prophase, metaphase, anaphase, and telophase. Mitosis in most cells takes less than one hour. Between one mitosis and the next, there can be an interval, from a few hours to several days in length, during which a cell is said to be in interphase. The entire period between the midpoints of two successive mitoses is called the cell cycle.