Modern cell theory is also known as cell doctrine or cell principle.
This theory states that:
(i) The bodies of all living beings are made up of cells and their products.
(ii) Cells are the structural and functional units of living organisms.
(iii) Life exists only in cells because all the activities of life are performed by cells.
(iv) Each cell maintains its individuality. It has a specific internal environment and homeostasis.
(v) Growth of an organism involves the growth and multiplication of its cell. New cells arise from pre-existing cells through division.
