Today, the Railroad Retirement program is closely tied to the far better-known Social Security program, and although the Railroad Retirement program and Social Security share a number of common elements, key differences also exist between the two in areas such as funding and benefit structure.
The Cell Cycle. The cell cycle is the life cycle of a cell (Figure 5.3). At the end of the cell cycle, after mitosis has taken place, the parent cell no longer exists; it has given rise to two daughter cells. There are two phases in the cell cycle, interphase and mitosis.
Events during Mitosis. Interphase: Cells may appear inactive during this stage, but they are quite the opposite. This is the longest period of the complete cell cycle during which DNA replicates, the centrioles divide, and proteins are actively produced.