A cell is the smallest unit of life, also called the 'building blocks of life' because cells multiply and differentiate to form a multicellular organism as well as give rise to new organism by forming gametes or reproductive spores. A living thing, whether made of one cell (like bacteria) or many cells (like a human), is called an organism. Thus, cells are the basic building blocks of all organisms. Several systems that function together form an organism (like a human being).
