Final answer:
True, melanin is the primary pigment in tanning. It is produced in response to UV exposure, leading to skin darkening as a protective measure. Over time, the tan fades as melanin-containing cells are shed from the skin.
Step-by-step explanation:
Melanin is indeed the primary pigment involved in tanning, so the statement is true. When the skin is exposed to UV rays from the sun or a tanning salon, melanin synthesis increases, and the pigment is accumulated in the keratinocytes which leads to a darker skin tone, or tan. This process is a protective mechanism to shield the DNA of epidermal cells from potential UV ray damage. Melanin comes in two primary forms: eumelanin, providing black and brown colors, and pheomelanin, offering a red hue. The amount of melanin in one's skin varies to maintain a balance between sunlight exposure, protection from UV radiation, and the production of necessary nutrients like folic acid and vitamin D.
Aside from melanin, other pigments such as carotene and hemoglobin also contribute to skin color, particularly in skin with lower melanin levels. It's important to note that melanin production and accumulation is an impermanent adaptation. Over time, as melanin-filled keratinocytes are naturally shed from the skin, the tan fades, which is why maintaining a tan requires ongoing sun exposure.