Final answer:
The basal cell layer of the epidermis is known as the stratum germinativum or stratum basale, which is the deepest layer where stem cells produce keratinocytes.
Step-by-step explanation:
The layer of the epidermis that is also known as the basal cell layer is b. stratum germinativum, or stratum basale. This deepest epidermal layer attaches the epidermis to the basal lamina with a basement membrane located below it. In this layer, the basal cells are stem cells responsible for producing new keratinocytes.
As the newly formed keratinocytes are produced by these stem cells in the stratum basale, they get pushed upwards, creating the multiple layers of the epidermis.