Is the formation of the outer layer of skin cells due to programmed cell death?

The formation of the outer layer of skin cells, known as the stratum corneum, involves a process called keratinization, which is indeed significantly influenced by programmed cell death, also known as apoptosis. During keratinization, the cells in the lower layers of the epidermis undergo a series of changes while moving towards the skin's surface. As these cells migrate upward, they fill with the protein keratin and eventually die, forming a tough, protective layer.

This programmed cell death is a crucial aspect of skin homeostasis, as it allows for the efficient turnover of skin cells. The outermost layer is composed of dead, flattened cells that are continuously shed and replaced by new cells from below. This process helps maintain the integrity of the skin barrier, providing protection against environmental threats while also facilitating the removal of damaged cells.

Thus, the answer is correct as programmed cell death plays a fundamental role in the formation of this outer layer of skin cells, contributing to both structure and function in skin biology.