Do yout agree that 'A cell is a building unit of on organism'. If yes, explain why?

Explanation

In unicellular organisms, single cell is capable of performing all the functions of life. In multicellular organisms, cells are first organized to form tissues. Different types of tissues get organized to form organs with specific function. Many organs are grouped together to constitute organ system. Many organ systems together constitute an organism. Therefore, cell is a building unit of an organism.