What is considered the basic unit of life?

The cell is regarded as the basic unit of life because it is the smallest structural and functional unit capable of performing all the processes necessary for life. Cells provide the fundamental building blocks that make up more complex structures in living organisms. They can carry out essential functions such as metabolism, growth, and reproduction independently.

In contrast, tissues, organs, and organisms are more complex arrangements made up of one or many cells. Tissues are groups of similar cells working together to achieve a specific function, organs are structures composed of different types of tissues that perform specialized tasks, and organisms are living entities that can be made up of many systems formed from multiple organs. Therefore, while these other options represent levels of biological organization, the cell stands alone as the most basic functional unit that defines life.