The Mitotic Phase of the Cell Cycle - Essay Example

Mitosis is a complex process that takes place only in eukaryotic cells and the process is known to vary in different species. Animals for instance are known to undergo a form of mitosis called open mitosis. This is where the nuclear envelope disintegrates before the chromosomes separate. Fungi on the other hand are known to undergo closed mitosis where the chromosomes divide within an unbroken cell nucleus (Golitsin and Krylov, 100-150). The process is divided into several stages and these are a result of the different sequences of events that take place upon the completion of one activity to pave way for another.

There are six stages in mitosis and these include interphase, prophase, prometaphase, metaphase, anaphase, and lastly telophase. During the process, the pairs of chromatids shorten and attach to fibers which then pull the sister chromatids to the opposite ends of the cell. Cytokinesis then occurs to create two identical daughter cells (McAinsh, 100-330).Interphase: here the cell prepares for cell division by manufacturing proteins and cytoplasmic organelles. This phase is divided into three stages, first gap (G1), synthesis(S), and second gap (G2).

The last second phase is where chromosomes replicate (McAinsh, 100-330). Prophase: the chromatin shortens into a chromosome. Since at the S phase the genetic material is duplicated, the replicated chromosomes have two sister chromatids that are bound together at the center. At this stage, the centrosomes (coordinating centers for cell microtubules) are pushed to the opposite sides of the cell (McAinsh, 100-330).Prometaphase: the nuclei envelop disassembles and microtubules come into the nuclei space.

Each chromosome then forms two kinetochores at the centromere and each one is attached to each chromatid (Snedden, 1-48).Metaphase: the two centrosomes begin pulling the chromosomes along their attached centromeres toward the end of the cells. The chromosomes become tensed from the longitudinal pull. The centromeres of the chromosomes align along the metaphase plates (McAinsh, 100-330). Anaphase: the proteins that bind the sister chromatids separate and are then pulled apart by the shortening kinetochore microtubules.

They then move to the centrosomes to which they are attached. The nonkinetochore microtubules lengthen and pull the centrosomes to the opposite ends (Snedden, 1-48).Telophase: the nonkinetochore microtubules will continue to lengthen in the process elongating the cell even more. The sister chromosomes attach at opposite ends of the cell. A new nuclear envelope forms around each of the sister chromosomes that have been separated. The sets of chromosomes then unfold back into chromatin thereby completing mitosis (McAinsh, 100-330).