Skin is classified as which biological structure?

• A. Tissue
• B. Organ
• C. System
• D. Cell

Answer: (B)

An organ is a structure formed by different tissue types that work together to perform a specific function. The skin fits this idea because it brings together several tissues into one integrated unit. The outer layer, the epidermis, is mainly epithelial tissue, while the underlying dermis contains connective tissue along with nerves, blood vessels, glands, and other components. This coordinated arrangement supports multiple roles—protection, sensation, temperature regulation, and metabolic activities like vitamin D synthesis. It isn’t a tissue by itself, since a tissue is a group of similar cells, and it isn’t a system, which would be a group of organs, nor a single cell, which the skin obviously is not. The skin’s structure and combined functions define it as an organ.