What is the basic unit of life?

The cell is recognized as the basic unit of life because it is the smallest structural and functional unit capable of performing all life processes. Cells are the building blocks of all living organisms, whether unicellular, like bacteria, or multicellular, like plants and animals. They contain essential components, such as genetic material, cytoplasm, and a plasma membrane that facilitates various biological functions necessary for life, including metabolism, growth, and reproduction.

In contrast, organelles are specialized subunits within a cell that perform particular functions, such as mitochondria for energy production or ribosomes for protein synthesis. Tissues are groups of similar cells that work together to perform a specific function, and organs are structures made up of different types of tissues that work together to carry out complex tasks. While these components are vital to organismal structure and function, they do not themselves fulfill the criteria of being the fundamental unit of life; that role belongs distinctly to the cell.