Dear aspirant,

Hope you are doing well. Cell is called the structural and functional unit of life because all living organisms are made up of cells and also because they form the building blocks of the main organs of these organisms. It is called functional unit because the cells basically carry out all the functions in our body and carry our all the processes essential for living. Hope you find this helpful. Thank you.

https://learn.careers360.com/ncert/questions/cbse_9_class-science-the_fundamental_unit_of_life/