BIOLOGY RESEARCH PAPER ULTRAVIOLET RAYS & DNA FACTORS THATINFLUENCE SKIN CANCER BY PATRICE WILLIAMS BSC 1005 LIFE IN ITS BIOLOGICAL ENVIRONMENT PROFESSOR MOORE July 30, 2001 Ultraviolet Rays & DNA Factors thatInfluence Skin Cancer "Cancer", its a disease that has claim the lives of millions, its a disease that so far has no known cure, and its a disease that has many different forms. Cancer is defined as "a malignant form of tumors, which are tissue masses that arise through mutations in the genes that govern cell growth and division" (Starr, 1999, p. 213). Skin cancer is just one of the many forms of cancer that effects us and is the most common cancer in the U. S. Like so many others, I would assume that the major cause of skin cancer was the ultraviolet rays from the sun.

However, there are other factors involved. Our DNA plays a major role in how cancer affects us, it has a major role in genetics too, therefore, environmental and heredity both are factors that assume roles in the effects of cancer. In order to understand these two factors, they must be defined and explained. If they both have major effects on the way skin cancer affects an individual, than what are some preventive measures that we need to know about each. First, skin cancer and our skin structure must be defined and explained. It is a form of cancer, which is a mutation in the genes that affect cell growth and division.

"Skin cancer is a disease in which malignant cells are found in the outer layer of the skin" (HYPERLINK ' web ' web). One form of skin cancer is melanoma, is the rarest but the most virulent of the skin cancers. It is responsible for 75% of all deaths from cancer. It is "a cancer that arises in the melanocytes, the cells that produce melanin.

Melanin is the pigment that gives our skin, hair, and eyes their color and that allows us to tan" (Schofield & Robinson, 2000, p. 1). Melanocytes are located throughout the body, "in the retina of the eye and in the linings of the mouth, nose, anus, rectum, vagina, and spinal cord," (Schofield & Robinson, 2000, p. 6). However, majority of them are located in the skin. The purpose of these cells are to make melanin to protect our skin cells from the sun's ultraviolet rays (UV rays).

The melanocyte cells are found between the dermis (the second layer of skin) and the epidermis (the outermost layer of skin). Normally every ten cells found within the epidermis and dermis are melanocytes the others are cells called keratinocytes. Melanin is made inside the melanocytes then is transferred along the cells' long arms (dendrites) to nearby keratinocytes in the epidermis. Melanoma arises when there is an uncontrollable increase in the reproduction of melanocyte cells. Although, skin cancer mostly develops just below the skin's surface, where an existing mole is located, it can get into the blood vessels and lymphatic channels in the dermis and travel throughout the body.

Basically, cancer develops when there is an abnormal growth or reproduction in cells. One of the factors of that can cause skin cancer in humans is Ultraviolet light (UV). "Ultraviolet (UV) light is essential for life because it is used by plants to generate their energy (and in turn, of course, people and animals generate much of their energy from plants. ) " (Schofield & Robinson, 2000, p. 21). However, that same UV rays from the sun causes the damage to the melanocyte cells, which brings the onsite of melanoma.

UVA, UVB, and UVC are three kinds of ultraviolet lights.