why the cell called structural and functional unit of life
Answers
A cell is called the structural unit of life because every form of life is made out of cells, it would be usefull to say that life comes in all sorts of sizes ranging from bacteria to a blue whale but just as bacteria is a type of cell, blue whale are made of cells as well just that they are conected and have different functions (the science that study the different types and their distribution in the body is called histology) so that does it for the structural part of question.
Now cells might be called functional unit of life because they are the factories in which every chemical reaction and every phisical action is taking place, that let you keep on living take breathing of instance the phisiological process of breathing and gaining 02 into your blood cells can only be true understood if you understand the phisical and chemical interactions that happen in your body cells.