Final answer:
Keratinocytes are skin cells that make up the majority of the epidermis.
Step-by-step explanation:
Keratinocytes are skin cells that are a fundamental part of the epidermis, the skin's outer layer. These cells manufacture and store the protein keratin, which gives hair, nails, and skin their hardness and water-resistant properties. Almost 90 percent of epidermal cells are keratinocytes.
They are found in all layers of the epidermis except the stratum basale. As keratinocytes in the stratum corneum (the outermost layer) die, they are shed from the skin's surface and are replaced by new cells coming from the deeper layers.
When a cut occurs and bacteria enter the wound, different types of cells within the skin respond to the infection. It is Langerhans cells, which constitute about 1 percent of epidermal cells, that function as part of the immune system. They detect and fight pathogens that enter the skin. Therefore, in response to the student's question which asks, "If you cut yourself and bacteria enter the wound, which of the following cells would help get rid of the bacteria?", the correct answer would be c. Langerhans cells.
Based on the provided reference options, keratinocytes (Option B) do not have immune functions like fighting off bacteria, thus the correct choice to the initial question "What are keratinocytes?" is B. Skin cells.