What is the basic unit of life?

The basic unit of life is the cell. Cells are the smallest structural and functional units of living organisms. They are often referred to as the "building blocks of life" because all living things, from the simplest bacteria to complex multicellular organisms like humans, are composed of cells. Each cell carries out essential processes such as metabolism, growth, and reproduction, which are vital for sustaining life.

Cells can exist as independent organisms, like unicellular organisms, or as part of larger multicellular structures, where they work together to form tissues, organs, and systems. This organization underscores the importance of cells in the context of biological hierarchy, where they serve as the foundational units that allow for more complex life forms to exist.