MCAT Question A Day - 7/7/13 - Answer!
Which substance produced in the skin can act to reduce the probability of skin cancer?
A. Keratin
B. Melanin
C. Sebum
D. Sweat
The correct answer is (B). UV radiation is mutagenic and can be absorbed by DNA in skin cells. Melanin absorbs UV radiation, reducing the chances of it reaching the cells below. Keratin and sebum help conserve moisture in the skin.
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