Pertanyaan

Read the following text and answer the question! Cancer What is cancer? It is actually a group of more than one hundred separate diseases. Most of us are fear of cancer. It is reasonable because next to the heart disease, cancer is the second leading caused of death. Cancer cells come from normal cells because of mutation of dea. Those mutation can occurs spontaneously. The mutation may be also induced by other factory such as: nuclear and electromagnetic radiation, viruses, bacteria and fungi, parasites, heat, chemicals in the air, water and food, mechanical cell-level injury, free radicals, evolution and ageing of DNA, etc. All such factory can produce mutation that may start cancer. Cancer cells are formed continuously in the organism. It is estimate that there are about 10,000 cancer cells at any given time in a healthy person. Why do some result in macroscopic-level cancer and some do not? First, not all damaged cells can multiple and many of them die quickly. Second, those which potentially divided and form cancer are effectively destroyed by the mechanisms available to the immune system. Therefore cancer develop if the immune system is not working properly or the amount of cells produce is too great for the immune system to eliminated. Source: https://www.digital-recordings.come/ Questions: What factors caused cancer?