What is the basic unit of life?

The basic unit of life is a cell, which is the smallest structural and functional unit of an organism. Cells carry out all the essential processes of life, such as metabolism, energy production, and replication. They are often referred to as the "building blocks of life" because all living organisms, from single-celled bacteria to complex multicellular organisms like humans, are composed of cells.

Cells can perform various functions depending on their type, such as nerve cells transmitting signals or muscle cells facilitating movement. Understanding that cells are the fundamental units helps clarify how larger structures, such as tissues (composed of groups of similar cells) and organs (composed of different tissues), are organized in living organisms.

In contrast, atoms are the basic units of matter but do not represent life. Tissues represent groups of cells working together, but they are not the smallest unit of life themselves. Organs consist of multiple tissues working in tandem to perform complex functions, making them a higher level of organization beyond cells.