The basic unit of all living matter:

The basic unit of all living matter:

• A. Cell
• B. Tissue
• C. Matter
• D. Bulla

Answer: (A)

The fundamental unit of living matter is the cell—the smallest unit that can carry out the processes of life, including metabolism, growth, and response to the environment. Cells are the building blocks from which tissues, organs, and whole organisms are formed, so everything alive ultimately derives from cellular activity. In skin, for example, the epidermis is made of keratinocytes and other cell types, while the dermis contains fibroblasts and immune cells—all working through cellular functions. This concept explains why changes at the cellular level drive skin health, turnover, and barrier function, and why products and treatments are evaluated by how they interact with cells. The other options don’t fit because matter is any substance with mass (not a living unit), and bulla is a blister, a medical term for a skin lesion rather than a basic unit of life; tissue refers to a group of cells organized for a function, which is a level above the cell.

The fundamental unit of living matter is the cell—the smallest unit that can carry out the processes of life, including metabolism, growth, and response to the environment. Cells are the building blocks from which tissues, organs, and whole organisms are formed, so everything alive ultimately derives from cellular activity. In skin, for example, the epidermis is made of keratinocytes and other cell types, while the dermis contains fibroblasts and immune cells—all working through cellular functions. This concept explains why changes at the cellular level drive skin health, turnover, and barrier function, and why products and treatments are evaluated by how they interact with cells. The other options don’t fit because matter is any substance with mass (not a living unit), and bulla is a blister, a medical term for a skin lesion rather than a basic unit of life; tissue refers to a group of cells organized for a function, which is a level above the cell.