The epidermis of the skin consists of many layers of tightly packed cells. The outermost layer of cells is dead. Which best describes why this occurs?

The epidermis has no blood vessels; they are located in the underlying dermis. Cells near the bottom of the epidermis receive nutrients by diffusion, but as they move toward the surface they become keratinized and die. Therefore, B best describes the reason the outermost cells are dead.

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