Cancer 2

Essay by EssaySwap ContributorHigh School, 10th grade February 2008

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Introduction to Cancer The individual unruly cell that has escaped the normal regulatory control mechanisms is the basic unit of cancer.

Inside the nucleus is a substance called DNA, which contains genetic information for the body, organized in units called genes. These genes contain the complete plans for the body. They determine weather you have a blue or a green eye, weather you will have two or four legs, etc. They send out information that tells the cell what chemicals to make, as well as how much and when to make them.

In nucleus, genes are joined together, like beads on a chain, into structures called chromosomes. A normal human body cell has 46 chromosomes, which contain an average of several thousand genes each. During certain phases of the cell's life cycle, the chromosomes are stretched out into long, thin strands, and they are tangled together into a network called chromatin.

In addition to genes, chromosomes contain proteins, some of which cover the genes that are not "turned on" at the particular time.

The original genetic information, stored in a coded form DNA, is carried out of the nucleus by RNA and then translated into proteins by ribosomes. 70% of oncogenes are located in the weak points of the chromosomes-hereditary regions where the DNA molecule may break or its portions may be rearranged into new combinations. Actually most of the times, the nucleus and the DNA are constantly exposed to substances that may alter the genes. But these alterations are almost always prepared by intricate mechanism with the function of preventing havoc in the cell. But if these changes persist in a given cell, that altered gene will breed true. Such damage to the chromosome may remove the oncogene from the influence of the genetic control mechanisms that normally govern...