Cell biology represents chemical system in animal and plants by which its maintain cell structures and reproduce new cells in body and therefor cells are called fundamental units of life in all living things. Cell theory basically divided in three parts : a) All living cells are made-up of one or more cells, b) In any organism, cells are basic units of structures and functions, c) cell are results of replications of existing cells.
All cells are not same that means in same organism having different cell shape, size and structure and also we can say that cells having diversity