Explanation Text

How Cancer Occurs

source : gambarselkanker.com

source : gambarselkanker.com

What is cancer? It is actually a group of more than one hundred separate diseases. Most of us are fear from cancer. It is reasonable because next to heart disease, cancer is the second leading cause of death.

Cancer cells come from normal cells because of mutations of DNA. Mutations can happen by chance when a cell is dividing. They can also be caused by the processes of life inside the cell. Or they can be caused by things coming from outside the body, such as the chemicals in tobacco smoke. And some people can inherit faults in particular genes that make them more likely to develop a cancer.

Some genes get damaged every day and cells are very good at repairing them. But over time, the damage may build up. And once cells start growing too fast, they are more likely to pick up further mutations and less likely to be able to repair the damaged genes.

Cancer cells are formed continuously in the organism. It is estimated that there are about 10,000 cancer cells at any given time in a healthy person. Why do some result in macroscopic-level cancers and some do not? First, not all damaged cells can multiply and many of them die quickly. Second, those which potentially divide and form cancer are effectively destroyed by the mechanisms available to the immune system.

Therefore cancer develops if the immune system is not working properly or the amount of cells produced is too great for the immune system to eliminate.

Lexicogrammatical Features   :

1.      Focus on generic, non human participants

2.      Use of simple present

3.      Use temporal and causative relations

4.      Use some passive verbs