IT is well known that the mind is unable through the eye to estimate any large number of objects without counting them successively. A small number, for instance three or four, it can certainly ...

Cell differentiation is the process by which specialised cells such as muscle, skin or nerve cells, are formed from less specialised cells such as stem cells and their progenitors. Differentiation ...

Plant cells are also able to become longer as they grow. This process is called cell elongation and occurs throughout the plant, not just in the meristems. Cell elongation does not occur in animals.