There are over 10,000,000,000,000 cells in your body. Although these cells can do different jobs, each one has a nucleus with the same set of 46 chromosomes.
Yet all of this came from a single cell with one set of 46 chromosomes. Within about 6 minutes of fertilization, this cell copied itself to make two cells. This was your first experience of mitosis. Soon after, these two cells copied themselves to make four and so on. You have been subject to mitosis ever since (billions of times).
By copying the original 46 chromosomes, your body has created more than a hundred billion kilometers of DNA - that 's enough to stretch around the Earth 2,500 times. Mitosis has copied a total of about 100 ZB of data. As a rough estimate, this is equivalent to making a million copies of all the hard drives in the world. [1 ZB is a zeta byte of data. This is 1 with twenty four zeros after it].However, although this is an amazing feat, it does sometimes go wrong. This can result in a cancerous growth.
Cancer is a disease that originates in our own cells. A change in the DNA causes a special gene called an oncogene to be switched on. This leads to uncontrollable cell reproduction by mitosis. And this is called Oncogenesis and in the layman 's word is called cancer.
When cells begin to grow in an uncontrolled way, they form a lump called a tumor. Some tumors stay within one specific area. They do not spread into surrounding tissues and may not cause any problems. If it is easy to do so, these benign tumors are usually removed by surgery. There are usually no further problems.
Cancers are dangerous types of growths called malignant tumors. In this type of tumor the cells invade the surrounding tissues. Cancer cells
Step 1 - The primary tumor develops as a group of cells that are growing out of control.
Step 2 - The tumor gets bigger and stimulates blood vessels to supply it from the surrounding tissues.
Step 3 - Tumor cells squeeze
Cited: "Cancer - choosing a treatment program." Family Doctor. . "Cancer and its Causes." Aging well village. New York State Office of Aging. . "Cell Division and Cancer." School Science. . Friedlander, Ed. "Cancer: Causes and Effects." . Quillin, Patrick. "Cancer and Its Causes - Know your Enemy." 15 Oct 2005. Health World. .