A divide is the highest ridge of terrain separating river basins. Divides can be relatively small and cover just a few dozen miles, or they can stretch thousands of miles. On either side of a divide, water drains into separate basins. Continue Reading.
Concept 2: Mitosis and the Cell Division Cycle. Cells that are growing and dividing go through a repeating series of events called the cell division cycle (or cell cycle). During the first phase (G1), the cell grows and prepares for DNA replication, which occurs in the subsequent S phase. Further growth takes place in the G2 phase, and finally mitosis occurs in the M phase. G1, S, and G2 are collectively called interphase.
In eukaryotes, the cell cycle consists of four discrete phases: G 1, S, G 2, and M. The S or synthesis phase is when DNA replication occurs, and the M or mitosis phase is when the cell actually divides.The other two phases â G 1 and G 2, the so-called gap phases â are less dramatic but equally important.ells typically spend far more time in interphase than they do in mitosis. Of the four phases, G 1 is most variable in terms of duration, although it is often the longest portion of the cell cycle (Figure 1). Figure 1: The eukaryotic cell cycle. Â© 2013 Nature Education All rights reserved.