Every cell in the human body contains the same set of instructions. Why is it that some cells are muscle cells, some cells are nerve cells, and other cells are skin cells?

Different genes are expressed in different cells

Explanation:

The instruction is provided to the cell by the genetic material in the form of genes. Genes are the physical segment present on the DNA which can code for a specific protein.

The genes are present in the cells in the condensed form called chromosome which is present in all the cells of the body.

Although all the cells contain the same type of chromosomes or genes but they differentiate to perform different functions.

The differentiation process involves the expression of different genes in different cells as a result of which different proteins are formed in different cells and they perform different functions.