Anatomy & physiology
The cell cycle is composed of four stages. “Most cells periodically divide into two daughter cells, so a cell has a life cycle extending from one division to the next. This cell cycle is divided into four main phases” (Saladin p 128).The first stage is referred to is the G1 stage or the gap phase. The “G” is short for growth. However, during this stage cells do many things. They grow, carry our tasks, and break down protein. They also gain the material they need to replicate their DNA and this happens shortly after. The second phase is the synthesis phase, in this phase nuclear DNA and centrioles make duplicate copies of themselves. They then are distributed between the daughter cells in the next phase of division. “The G2 phase the second growth period of the cell cycle, following DNA replication and preceding prophase, during which the cell forms the materials that make up the spindle” (Dictionary.Com). The next phase is G2 or the second gap phase. It is a short process in this phase, in which the DNA replicates itself and divides itself. In the G2 phase it is similar to phase one with further growth, completes centriole replication, synthesis enzyme replication, and makes more organelles. Any errors are fixed and consistency in DNA are handled at this point. The final of the four phases is M phase, also know as the Mitotic phase. This also is a short phase taking only one to two hours where the nucleus forms into two new daughter cells. According to Saladin, the first G Phase, is when the DNA cells are getting prepared to replicate in the following phase. He also states that the next phase that they do actually replicate in cell devision is in the G2 phase, but it is a quick process only lasting a short four to six hours. During this time is when errors can be detected.
g2 phase. (n.d.). Dictionary.com Unabridged. Retrieved May 05, 2016 from Dictionary.com website http://www.dictionary.com/browse/g2-phase
Saladin, K.S. (2015). Anatomy & physiology: The Unity of Form and Function. New York, NY: McGraw- Hill