What is the basic unit of life?

The basic unit of life is cells. Cells are the fundamental building blocks of all living organisms, from the simplest unicellular bacteria to complex multicellular organisms like humans. Each cell functions as an independent unit, carrying out essential life processes such as metabolism, growth, and reproduction.

Cells come in various types tailored to their specific roles. For example, muscle cells are specialized for movement, while nerve cells are adapted for transmitting signals. As the smallest structural and functional units, they play a crucial role in the organization of living systems. When cells group together, they form tissues, which in turn can combine to create organs. This hierarchical structure shows that while other options represent higher levels of biological organization, they are made up of cells. Understanding that cells are the foundation of life is vital in cell biology and broader biological sciences.