Cancer
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. Those mutations can
occur spontaneously. The mutations may be also induced by other factors 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 factors can
produce mutations that may start cancer.
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.
Analysis :
Ø Social
Function : to explain about Cancer.
Ø Generic
Structure :
-
a general statement to position the reader: Most of us
are fear from cancer It is reasonable because next to heart disease, cancer is
the second leading cause of death.
-
a sequenced explanation of why or how something
occurs: Cancer cells come from normal cells because of mutations of DNA. Those
mutations can occur spontaneously. The mutations may be also induced by other
factors 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
factors can produce mutations that may start cancer.
Ø Significantn
Lexicogramatical features : focus on generic, non human participants.
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