It is a DUI offense committed by a minor if a driver under 21 years old has __________of alcohol in his or her system.

In many jurisdictions, a driver under 21 years old is considered to be committing a DUI (Driving Under the Influence) offense if they have any measurable amount of alcohol in their system. This is often referred to as a "zero tolerance" policy, which means that drivers under the legal drinking age of 21 can face penalties for having a blood alcohol concentration (BAC) of 0.01% or higher, although specific laws can vary by state or country.

These laws are designed to prevent underage drinking and driving, emphasizing that any consumption of alcohol by minors is unacceptable while operating a vehicle. Penalties for a DUI offense committed by a minor can include fines, license suspension, mandatory alcohol education programs, or even jail time depending on the severity of the offense and local laws.

To ensure accurate understanding, it's crucial to refer to the specific DUI laws applicable in the relevant state or region, as they can differ significantly.