Which term describes the protective outer layer of the body's cells?

The term that describes the protective outer layer of the body's cells is the cell membrane. The cell membrane, also known as the plasma membrane, serves a crucial role by providing a barrier that separates the interior of the cell from the external environment. This structure is comprised mainly of a phospholipid bilayer, which not only protects the cell's contents but also regulates the movement of substances in and out of the cell, thus maintaining homeostasis.

Understanding the functions of the cell membrane is essential, as it plays a key role in cell communication and transport mechanisms, allowing vital nutrients to enter the cell while keeping harmful substances out. Additionally, it enables the cell to interact with other cells and respond to changes in the environment.

The other terms do not describe the outer layer of the cell. Cytoplasm refers to the jelly-like substance within the cell membrane that contains the organelles. The nucleus is the organelle that houses the cell's genetic material, and chromatin is a form of genetic material found in the nucleus, consisting of DNA and proteins. Each of these components is important for cellular function, but they do not serve as the protective barrier that the cell membrane does.