Final answer:
The statement is true; the youngest keratinocytes are indeed found in the stratum basale, which is the deepest layer of the epidermis containing stem cells that form these keratinocytes.
Step-by-step explanation:
The statement that the youngest keratinocytes are found in the stratum basale is true. The stratum basale is the innermost or deepest layer of the epidermis, where basal cells, which are stem cells, divide to form all keratinocytes for the epidermis. These young keratinocytes are initially cube-shaped and contain almost no keratin. As they mature, they begin to produce more keratin and are pushed upwards to form the outer layers of the skin.
The stratum basale also contains melanocytes, which produce melanin and give hair and skin their color while protecting against UV radiation. In contrast, the stratum corneum contains dead keratinocytes that regularly slough away. It is also important to note that Langerhans cells are commonly found in the stratum spinosum, not the stratum basale or stratum lucidum.