NSCI 1404 Study Guide - Midterm Guide: Cell Membrane, Nucleolus, Nuclear Membrane
2 Oct 2016
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Document Summary
At a certain point - the restriction point - the cell is committed to division and moves into the s phase. Each chromosome now consists of two sister chromatids. Metabolic changes assemble the cytoplasmic materials necessary for mitosis and cytokinesis. A nuclear division (mitosis) followed by a cell division (cytokinesis). The period between mitotic divisions - that is, g1, s and g2 - is known as interphase: regulation of the cell cycle. Control of the cell cycle is necessary for a couple of reasons. First, if the cell cycle were not regulated, cells could constantly undergo cell division. While this may be bene cial to certain cells, on the whole constant reproduction without cause would be biologically wasteful. Second, internal regulation of the cell cycle is necessary to signal passage from one phase to the next at appropriate times. This regulation is not achieved through strict time constraints, but rather with feedback from the cell.
