Which of the following is true about extra keratin during tanning?

Extra keratin during tanning indeed migrates to the surface and thickens the skin. This process occurs as the skin responds to UV exposure by producing more keratin, which is a protective protein. The thickening of the skin creates a barrier that helps shield underlying layers from further UV damage. This can be particularly beneficial as it provides some level of protection against potential harmful effects of overexposure to UV rays, although it is important to note that this does not eliminate the risk of skin damage.

The presence of extra keratin can also aid in the formation of a tan by creating additional pigmentation and providing a more uniform appearance. Understanding this response is crucial for recognizing how the skin adapts to UV exposure and the implications it has for tanning practices.