What is the basic unit that all living things are composed of?

All living organisms are fundamentally composed of cells, which are recognized as the basic unit of life. Cells serve as the structural, functional, and biological unit that carries out all essential processes needed for life. They can vary in complexity, from simple unicellular organisms like bacteria to complex multicellular organisms such as plants and animals, but every living entity comprises at least one cell.

Atoms and molecules, while essential components of matter and part of the cellular structure, are not considered units of life themselves. Tissues, on the other hand, are groups of similar cells that work together to perform a specific function. However, tissues cannot exist independently as the basic unit of life; they rely on the cells that compose them. Thus, recognizing the cell as the fundamental unit underscores its pivotal role in the organization and function of all living organisms.