In sexual reproduction both male and female sex cells are produced. Since the daughter cell is an exact replica of the parent, it is called a clone (The Two Methods, n.d.). Each cell receives the exact same genetic material as it divides which makes it an exact copy of the parent cell. In asexual reproduction there is no need to have two of the species. Differentiate between asexual and sexual reproduction These oncogenes can also prevent a damaged cell from eliminating itself, which causes replication of that mutated cell (Chow, 2010). These are the proteins involved in cell regulation and sometimes they become altered which not only creates abnormal protein products but allows cell division to occur too rapidly which contributes to tumor growth (Chow, 2010). The abnormal cell growth can be caused by what are known as oncogenes (Chow, 2010). These mutated cells tend to divide very rapidly and can lead to malignant tumors (Chow, 2010) and have the ability to spread through the body. Sometimes, these checkpoints lose their sensitivity and damaged or mutated cells are allowed to replicate (Collins, Jacks & Pavletich, 1997). Analyze the loss of cell cycle controls in cancer cellsĪs discussed above, there are regulation mechanisms by which a cell is either approved for replication or programmed to die. Finally, telophase occurs in which the cell begins to form new internal parts such as the nucleus and becomes two new daughter cells (Phases of Mitosis, n.d.). Anaphase begins now in which the chromatids are now pulled apart towards opposite ends of the cell. In metaphase, the spindle has gathered the chromosomes and has now lined them up in the middle of the cell, ready to divide. By this phase, the chromosomes have stopped condensing and the envelope of the nucleus break down, releasing the chromosomes (Phases of Mitosis, n.d.). It is also in this phase that the nucleus disappears. The mitotic spindle starts forming between the centrosomes as they move apart. It is here that the chromosomes begin to condense, which makes them easier to be pulled apart. It then enters what is known as early prophase (Phases of Mitosis, n.d.). Just before mitosis, the cell is in interphase, where it has already copied its DNA. There are four basic phases of mitosis: prophase, metaphase, anaphase and telophase (Phases of Mitosis, n.d.). It is here that sister chromatids are evaluated to ensure they are attached properly to spindle microtubules before they are allowed to move on to anaphase (Boundless, 2016). The final checkpoint is the M-point near the end of the metaphase stage of mitosis. Again, it either gets corrected or it is prevented from entering mitosis. This regulator evaluates all the chromosomes to ensure they have been replicated properly and that the new DNA is correct and without mistakes or damage (Boundless, 2016). The next checkpoint occurs at the G2 phase. If damage has occurred, it either gets corrected or gets prevented from moving on to the next phase (Boundless, 2016). It is here that DNA gets evaluated and checked for damage. The first checkpoint is near the end of the G1 phase. These are points at which cell replication can be halted until certain conditions are met (Boundless, 2016). In eukaryotic cells, there are three main checkpoints. This is to help guarantee that cell mutations are not passed on to the next generation of cells. Explain the regulation of the cell cycleĮvery cell is regulated by particular checkpoints to ensure that the daughter cells are exact duplications.
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