What is the basic unit of life?

The basic unit of life is the cell. Cells serve as the fundamental building blocks of all living organisms, whether they are unicellular, like bacteria, or multicellular, like plants and animals. Each cell is capable of performing the functions necessary for life, including metabolism, growth, and reproduction.

While tissues are groups of similar cells that work together to perform a specific function, and organs are composed of multiple tissues working in concert to carry out a broader range of functions, neither can be classified as the basic unit of life. An organism refers to an entire living entity made up of one or more cells, but it is not a single unit itself when considering the definition of the basic unit of life. Thus, the cell is the smallest structure that can be considered alive and is fundamental to all biological processes.