1. Which layer of the skin is primarily responsible for thermoregulation? A. Epidermis B. Dermis C. Hypodermis D. Stratum corneum Answer: B. Dermis Rationale: The dermis layer contains blood vessels and sweat glands that help regulate body temperature. 2. Melanocytes are found in which layer of the skin? A. Stratum basale B. Stratum spinosum C. Stratum granulosum D. Stratum lucidum Answer: A. Stratum basale Rationale: Melanocytes, which produce the pigment melanin, are located in the stratum basale layer of the epidermis. 3. Which of the following cells are involved in the immune response of the skin? A. Keratinocytes B. Melanocytes C. Langerhans cells D. Merkel cells Answer: C. Langerhans cells Rationale: Langerhans cells are antigen-presenting cells that play a role in the skin's immune response. 4. What is the main function of the subcutaneous layer? A. Protection against pathogens B. Synthesis of vitamin D C. Insulation and energy storage D. Sensory perception Answer: C. Insulation and energy storage Rationale: The subcutaneous layer, primarily composed of adipose tissue, provides insulation and stores energy. 5. A patient presents with a severe sunburn. Which degree of burn does