Which term is the formal name for the deepest epidermal layer where cells divide and form new cells?

• A. Stratum granulosum
• B. Stratum germinativum
• C. Stratum lucidum
• D. Stratum corneum

Answer: (B)

The deepest epidermal layer where cells divide and form new cells is the stratum germinativum, also called the basal layer. This layer sits on the basement membrane at the dermal–epidermal junction and houses actively dividing stem cells that produce new keratinocytes. As these cells form, they migrate upward to replace those shed from the surface, building the protective epidermal barrier. The term germinativum literally means “forming new cells,” which is precisely what happens here.

For context, the layer above this one begins the process of keratinization, and layers further up include the granular layer where keratinization accelerates, the clear layer in thick skin, and the outermost cornified layer of dead cells.