Final answer:
The statement is false; dark-skinned individuals usually have more eumelanin, not pheomelanin, which results in black to brown pigmentation. Eumelanin and not pheomelanin are responsible for darker skin tones and protect the skin from UV damage.
Step-by-step explanation:
The statement that people with dark skin pigmentation mostly have pheomelanin in keratinocytes in the epidermis is false. Dark-skinned individuals generally produce more eumelanin, which is responsible for the brown to black pigmentation, not pheomelanin, which provides a red color. Melanocytes are cells located in the basal layer of the epidermis that produce the pigment melanin, which is then transferred to keratinocytes. The concentration and type of melanin produced by melanocytes and present in keratinocytes contribute to the skin's color, where higher concentrations of melanin result in darker skin tones. This process is a defense mechanism, as the accumulation of melanin in keratinocytes protects underlying skin layers from UV ray damage by absorbing and dispelling the harmful radiation.