Answer:
Each cell contains the same set of DNA but different genes are turned off or on depending on the cell's function.
Step-by-step explanation:
Every cell contains the same amount and same DNA in the nucleus, the only difference in differentiated cells is that DNA not relevant to the cell's function are silenced and hence not expressed. As the cell therefore only expresses genes to perform a specific function, it is said to be differentiated and specialised for that particular function. Note that the earlier answer given is incorrect.