New York State Cosmetology Practice Exam 2025 - Free Cosmetology Practice Questions and Study Guide

The dermis is the correct answer as it is the layer of skin that contains living cells. This layer is situated beneath the epidermis and is composed of connective tissue that provides strength and elasticity to the skin. It includes vital structures such as hair follicles, sweat glands, blood vessels, and nerve endings, which all contribute to the skin's overall function and health. The dermis is critical for regulating temperature and sensation.

In contrast, the epidermis, which is the outermost layer of skin, consists mainly of dead skin cells that have already undergone the process of keratinization, which gives the skin its protective barrier. The hypodermis, also known as the subcutaneous layer, is primarily composed of fat and connective tissue, serving as insulation and cushioning for the body. While the subcutaneous layer plays an essential role in fat storage and thermoregulation, it is not where living cells are primarily found. In summary, the dermis is the active layer containing the living cells necessary for various skin functions.