UV light does not just create repairable dimers in DNA bases, it can and does rip DNA apart. Enough exposure would cause more than enough irreparable damage to kill the cell and 99% of the cell being destroyed is certainly not salvageable.
Regional service for the airline is served by Delta Connection. Delta typically charges a fee for all checked bags on domestic flights, with most international flights having an allowance of one or two free checked bags per passenger, depending on destination.
Several major airlines waive checked bag fees for cardholders. For example, Delta SkyMiles cardholders can check one bag for free on Delta flights, and United MileagePlus Club cardholders can check two bags for free. (Restrictions and annual credit card fees may apply, and vary based on airline and type of card.