Q.What is called differentiation?

Differentiation is the process by which unspecialised cells become specialised in structure and function to form the different tissues and organs of the body.

When a zygote (fertilised egg) divides, the early cells are alike and unspecialised. As development proceeds, these cells gradually take on distinct shapes, internal structures and functions — a nerve cell, a muscle cell, a red blood cell and a gland cell all arise from the same original set of cells but end up very different. This process of change from an unspecialised to a specialised cell is called differentiation.

Key points:

• All body cells carry the same genes, but in each cell type different sets of genes are switched on and off; this selective gene expression is what drives differentiation.
• Differentiation produces the many specialised cell types, which then organise into tissues and organs. …