How are genes turned off and on?
How are genes turned off and on? Unless they schedule an appointment for highlights at the salon, many people who started out blond wave goodbye to their lighter-color hair as they grow up. Do the stresses of adulthood scare our childhood hair away? Or, let’s take another example of a childhood trait lost to adulthood — the ability to digest dairy. Thanks to an enzyme called lactase, most young children can digest milk. But as children grow older, it’s common to lose that ability. What’s happening here? It all comes down to a process called gene regulation. This is how our genes are turned off and on, for minor things like hair color and vital functions like protection from cancer. Within our bodies, we house trillions of cells, all busily going about doing their jobs while we enjoy our days. Each of those cells has a nucleus that contains our DNA — genetic material passed on to us from our
