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.
The Delta flight is cheaper. But check a bag at a cost of $25 for the first checked bag each way on Delta, and your total fare climbs to $256 -- more than the cost of the Southwest flight, which includes free first and second checked bags. Add a second checked bag for $35 each way on the Delta flight, and you'll pay a whopping $326.
Checked in baggage limit (weight and number of pieces) for passenger travelling to US? How Delta airlines can track your checked baggage? Can the cabin baggage weight limit be exceeded by 2-3 kgs for international travel (via Emirates flight) ? Do International airlines allow beauty creams in carry on baggage? How much carry-on baggage is permitted in Emirates Airlines for international student travelers?