Why will inserting a start codon into the beginning of a nonsense strand prevent a polypeptide from being made

Question

In my bio paper..
'Flavr Savr' tomotoes are tomatoes that have been genetically modified so that they take longer than normal to ripen. This delay has been achieved by disabling a critical tomatoe gene so that it fails to produce a protein that is needed for the ripening to occur. In order to disable the gene, a start codon is inserted at the beginning of the nonsense strand so that both the sense and nonsense strand are copied into mRNA.

Why will this prevent a polypeptide from being produced?

Answer 1

If both the sense and the nonsense are copied then there will be RNA strands capable of recognizing each other and forming a duplex RNA. When RNA is double stranded it can not be translated so the protein production of just this one product is blocked.

Answer 2

I would think probably not because whatever impact it has on the sense strand will only be read at the end so the mRNA would be transcribed as usual and translated because of its own start codon.