Every human starts out as a single cell, a fertilized egg, which then divides and develops into various cell types, such as skin cells, liver cells, and blood cells. Although these cell types look and function differently, they contain exactly the same DNA. But, how can the same genetic code be used to build more than two hundred different cell types in a human body? Researchers have shown that a cell’s function comes down to the thousands of genes that are present in a person’s DNA seque...
