Final answer:
Hannah will indicate the presence of melanin inside approximately 1000 melanosomes per keratinocyte for her skin model, reflecting the higher melanin content in darker skin. Melanocytes in the stratum basale produce this pigment, transferring it to keratinocytes to protect against UV light.
Step-by-step explanation:
Hannah is building a model of the skin for her esthetics program and must indicate the presence of a pigment in the skin of a dark-colored individual. In this case, Hannah will indicate the presence of melanin inside approximately 1000 melanosomes per keratinocyte (Option A). The skin's color is primarily determined by melanin production from melanocytes found in the base layer of the epidermis. Melanocytes produce melanosomes, which contain melanin and are transferred to keratinocytes. People with darker skin have melanocytes that produce more melanin, which protects the skin from UV damage.
The role of keratinocytes in the skin is significant as they make up most of the cells in the epidermis and have a life cycle that starts from the basal layer and moves towards the surface, eventually flaking off as dead cells. Melanocytes, located in the stratum basale of the epidermis, produce and transfer melanin to keratinocytes which play a crucial role in skin pigmentation and protection against UV light. The hypodermis and deep fascia are not directly involved in pigmentation but are important layers beneath the skin that provide insulation and support.