Cells are the building blocks of all living organisms .
- Every single living organism is made up of cells .
- The human body has from around a billion to trillions of cells .
- Similarly other organisms are also made of a large number of cells based on their complexity.
- Cells can be of various shapes and sizes based on their functions .
For example -
In the human body, the cells vary in their shape (could be polyhedral, oval, discoidal, cylindrical, spindle shaped) and size .
- The shape of the cells is decided by the function they perform :
- White blood cells that defend the body against pathogens are Amoeboid shaped
- Nerve cells are long and branched that conduct nerve impulses
- Muscle cell s are cylindrical or spindle shaped cells concerned with the movement of body parts