Final answer:
Melanin is the pigment produced by melanocytes in the skin to protect against ultraviolet sun rays. It exists primarily as eumelanin or pheomelanin, and its increased production upon UV exposure results in skin tanning, protecting the DNA from damage and the breakdown of essential nutrients. The option (A) is correct.
Step-by-step explanation:
The pigment produced to protect the skin from the effects of ultraviolet sun rays is called melanin. Melanin is a brown pigment produced by melanocytes in the skin and gives skin most of its color while preventing UV light from penetrating the skin. Melanin occurs in two forms: eumelanin, which provides black and brown colors, and pheomelanin, which gives a red color. The production of melanin increases upon exposure to UV rays from the sun or a tanning salon, causing a tan. This process enhances the protection of the skin by absorbing UV radiation, which could otherwise harm the DNA of epidermal cells and break down essential nutrients like folic acid.
Melanocytes produce melanin in organelles called melanosomes. These melanosomes are transferred to keratinocytes where they help to absorb UV light. The presence of more melanin in the skin enhances UV absorption, contributing to darker skin tones that are more resilient to sun damage. However, an excess of melanin can inhibit the production of vitamin D, which is vital for bone health and calcium absorption. Therefore, option (A) is correct.