Which of the following is known as the basic unit of life?

The cell is known as the basic unit of life because it is the smallest structural and functional unit that can perform all the processes essential for life. Cells are the building blocks of all living organisms, whether they are unicellular, like bacteria, or multicellular, like plants and animals. Each cell contains the necessary components to maintain homeostasis, carry out metabolic reactions, reproduce, and respond to their environment.

Tissues are made up of groups of similar cells that work together to perform a specific function, and organs are composed of different tissues that collaborate for a common purpose within an organism. An organism refers to a complete living being capable of independent existence, which is made up of multiple cells, tissues, and organs working in concert. Therefore, while tissue, organ, and organism are all essential levels of biological organization, the cell itself is the fundamental unit that embodies the characteristics of life.