Expert: Paras Anand - 1/20/2009

Question
How do some cells become brain cells and others become skin cells,when the DNA in ALL the cells is exactly the same, In other words, if the instructions are exactly the same,how does one cell become a brain cell and another a skin cell?

Answer
Hi! Teena,
Thank you for your question.
This process where cells perfrom specific function is called differentiation.
Although DNA is same in all the cells, the major tasks in the cells are carried by proteins. DNA transcribes to RNA and RNA translates to proteins. The regulation of transcription and translation, ultimately decididing which proteins will be available, makes a cell either skin or brain cell.

Best,