What causes the tanning of skin when exposed to uv radiation where is it found?

Excessive UV radiation causes sunburn along with other direct and indirect DNA damage to the skin, and the body naturally combats and seeks to repair the damage and protect theskin by creating and releasing further melanin into the skin's cells. With the production of the melanin, the skincolor darkens.

Air goes past the epiglottis and into the trachea when you breathe in. from there, it goes to your vocal cords in the larynx until it reaches the bronchi. from the bronchi, air passes into each lung.