What is the term for the fundamental unit of all living things?

The term for the fundamental unit of all living things is a cell. Cells are often referred to as the basic building blocks of life because they carry out essential functions necessary for organisms to survive. Each cell is capable of performing all the vital processes needed for life, such as metabolism, energy conversion, and reproduction.

Cells can exist independently as in unicellular organisms, or they can work in concert as part of multicellular organisms, forming tissues and organs. Tissues, which are made up of clusters of cells working together to perform a specific function, and organs, which are structures made up of tissues, rely on the cell as their foundational element. Furthermore, systems, such as the circulatory or digestive system, are composed of multiple organs that work together to perform more complex biological functions. This structural hierarchy highlights why the cell is considered the fundamental unit of all living things.