Question

shawn played catch on the beach with his brother nathan. before playing, shawn applied a sunscreen that coated his skin in a white compound, but nathan forgot to use sunscreen. complete the sentences. as they played, nathans skin quickly appeared to tan as uva waves activated melanin present in his blank. after an hour, nathans skin appeared sunburned. the dermis/epidermis in his skin could not absorb all the incoming uva and uvb waves waves dna in his skin, and blood rushed to the area, causing redness. shawn did not get a sunburn. the blank sunscreen on shawn’s skin protected him by reflecting the sun’s uv waves.

Explanation:

Melanin is a pigment in the epidermis (the outermost layer of skin) that gives skin its color. When UVA waves activate melanin, it can lead to tanning. The epidermis also plays a role in protecting the skin from UV waves. However, if there is too much UV exposure (like UVA and UVB waves), and the epidermis (along with other protective mechanisms) can't fully absorb or block the harmful rays, it can damage the DNA in skin cells. Sunscreen (especially physical sunscreens that work by reflecting UV waves) can provide an extra layer of protection, preventing UV waves from reaching the skin and causing sunburn.

Answer:

As they played, Nathan's skin quickly appeared to tan as UVA waves activated melanin present in his epidermis. After an hour, Nathan's skin appeared sunburned. The epidermis in his skin could not absorb all the incoming UVA and UVB waves, which damaged DNA in his skin, and blood rushed to the area, causing redness. Shawn did not get a sunburn. The physical sunscreen on Shawn's skin protected him by reflecting the Sun's UV waves.