Master the Biology Bash: 2025 MCAT Biological Systems Practice Challenge!

Melanocytes are specialized cells located in the epidermis, the outer layer of the skin, and are primarily responsible for the production of melanin. This pigment plays a crucial role in determining skin color and protecting the skin from the harmful effects of ultraviolet (UV) radiation from the sun. Melanin absorbs UV light, preventing it from damaging the DNA in skin cells, which helps reduce the risk of skin cancer.

Carotene, while present in the skin and contributing to coloration, is derived from dietary sources such as carrots and is not produced by melanocytes. Hemoglobin is a protein found in red blood cells responsible for transporting oxygen and gives blood its red color but is unrelated to pigmentation produced in skin cells. Collagen is a structural protein that provides strength and elasticity to the skin, but it does not contribute to pigmentation.

Thus, melanin is the correct answer as it directly reflects the pigment produced by melanocytes in the skin.