PATHOLOGY MCQ
SKIN
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Different tones of human skin color evolved
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in response to varying levels of UV radiation in the environment
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Randomly and for no reason at all
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Either A or B
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None of the above
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Explanation:
Detailed explanation-1: -Human skin pigmentation is the product of two clines produced by natural selection to adjust levels of constitutive pigmentation to levels of UV radiation (UVR). One cline was generated by high UVR near the equator and led to the evolution of dark, photoprotective, eumelanin-rich pigmentation.
Detailed explanation-2: -Melanin protects skin from the sun’s ultraviolet rays. These can burn the skin and reduce its elasticity, leading to premature aging. People tan because sunlight causes the skin to produce more melanin and darken.
There is 1 question to complete.