Question

Exposure to ultraviolet radiation changes skin tone by shielding the nucleus with

Answer 1

Melanin reduces ultraviolet induced DNA damage by absorbing or scattering the ultraviolet radiation that otherwise would have been absorbed by the DNA. This prevents the development of melanoma, a potentially deadly form of skin cancer, as well as other health problems related to exposure to strong solar radiation.

Answer 2

Melanocytes insert melanin into adjacent keratinocytes where it forms a protective UV radiation shield over their nuclei. ... Other people are predisposed to make melanin at a slower rate, which results in a lighter skin color. A person's rate of melanin production can be influenced by exposure to UV radiation.